[REL] v1.0.0-beta4

The way keys were handled in QWeb was mostly ok, but a little naive. It
is fine when we deal with a list of dom nodes, since the reconciliation
algorithm need only to be able to differentiate/reconcile nodes in that
list, but it is an issue with components, which needs to globally be
able to find themselves in their parent's children map.

Because of the way this was handled, there were situations were Owl
internal virtual dom would crash, since components wrongly assumed that
they were already rendered in a different place.

To fix this, we generalize the way keys are generated, by concatenating
all sub keys coming from each iteration loops.

closes #584

README.md

@@ -104,8 +104,8 @@ Submit a PR!
 
 If you want to use a simple `<script>` tag, the last release can be downloaded here:
 
-- [owl-1.0.0-beta2.js](https://github.com/odoo/owl/releases/download/v1.0.0-beta2/owl.js)
-- [owl-1.0.0-beta2.min.js](https://github.com/odoo/owl/releases/download/v1.0.0-beta2/owl.min.js)
+- [owl-1.0.0-beta4.js](https://github.com/odoo/owl/releases/download/v1.0.0-beta4/owl.js)
+- [owl-1.0.0-beta4.min.js](https://github.com/odoo/owl/releases/download/v1.0.0-beta4/owl.min.js)
 
 Some npm scripts are available:
 

doc/reference/component.md

@@ -628,10 +628,20 @@ as it will be translated to:
 
 ```js
 button.addEventListener("click", () => {
-  component.state.counter++;
+  context.state.counter++;
 });
 ```
 
+Warning: inline expressions are evaluated in the context of the template. This
+means that they can access the component methods and properties. But if they set
+a key, the inline statement will actually not modify the component, but a key in
+a sub scope.
+
+```xml
+<button t-on-click="value = 1">Set value to 1 (does not work!!!)</button>
+<button t-on-click="state.value = 1">Set state.value to 1 (work as expected)</button>
+```
+
 In order to remove the DOM event details from the event handlers (like calls to
 `event.preventDefault`) and let them focus on data logic, _modifiers_ can be
 specified as additional suffixes of the `t-on` directive.
@@ -946,7 +956,7 @@ For example, here is how we could implement an `ErrorBoundary` component:
     <t t-if="state.error">
         Error handled
     </t>
-    <t t-else="1">
+    <t t-else="">
         <t t-slot="default" />
     </t>
 </div>

doc/reference/context.md

@@ -57,7 +57,7 @@ class SomeComponent extends Component {
       <t t-if=device.isMobile>
           some simplified user interface
       </t>
-      <t t-else="1">
+      <t t-else="">
           a more advanced user interface
       </t>
     </div>`;

doc/reference/qweb_templating_language.md

@@ -28,7 +28,7 @@ generate a virtual dom representation of the HTML.
 ```xml
 <div>
     <span t-if="somecondition">Some string</span>
-    <ul t-else="1">
+    <ul t-else="">
         <li t-foreach="messages" t-as="message">
             <t t-esc="message"/>
         </li>
@@ -101,7 +101,7 @@ precisely, the result of a template rendering should have a single root node:
 <!–– ok: result has one single root node ––>
 <t>
     <div t-if="someCondition">foo</div>
-    <span t-else="1">bar</span>
+    <span t-else="">bar</span>
 </t>
 ```
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "owl-framework",
-  "version": "1.0.0-beta2",
+  "version": "1.0.0-beta4",
   "description": "Odoo Web Library (OWL)",
   "main": "src/index.ts",
   "engines": {

roadmap.md

@@ -1,6 +1,6 @@
 # 🦉 OWL Roadmap 🦉
 
-- Current version: 1.0.0-beta2
+- Current version: 1.0.0-beta4
 - Status: mostly stable
 
 This roadmap is only an attempt at predicting Owl's future.  Everything may

src/component/directive.ts

@@ -1,6 +1,6 @@
 import { QWeb } from "../qweb/index";
 import { INTERP_REGEXP } from "../qweb/compilation_context";
-import { MODS_CODE } from "../qweb/extensions";
+import { makeHandlerCode, MODS_CODE } from "../qweb/extensions";
 
 //------------------------------------------------------------------------------
 // t-component
@@ -189,7 +189,7 @@ QWeb.addDirective({
   extraNames: ["props"],
   priority: 100,
   atNodeEncounter({ ctx, value, node, qweb }): boolean {
-    ctx.addLine("//COMPONENT");
+    ctx.addLine(`// Component '${value}'`);
     ctx.rootContext.shouldDefineQWeb = true;
     ctx.rootContext.shouldDefineParent = true;
     ctx.rootContext.shouldDefineUtils = true;
@@ -197,7 +197,7 @@ QWeb.addDirective({
     let hasDynamicProps = node.getAttribute("t-props") ? true : false;
 
     // t-on- events and t-transition
-    const events: [string, string[], string, string][] = [];
+    const events: [string, string][] = [];
     let transition: string = "";
     const attributes = (<Element>node).attributes;
     const props: { [key: string]: string } = {};
@@ -205,13 +205,7 @@ QWeb.addDirective({
       const name = attributes[i].name;
       const value = attributes[i].textContent!;
       if (name.startsWith("t-on-")) {
-        const [eventName, ...mods] = name.slice(5).split(".");
-        let extraArgs;
-        let handlerValue = value.replace(/\(.*\)/, function(args) {
-          extraArgs = args.slice(1, -1);
-          return "";
-        });
-        events.push([eventName, mods, handlerValue, extraArgs]);
+        events.push([name, value]);
       } else if (name === "t-transition") {
         transition = value;
       } else if (!name.startsWith("t-")) {
@@ -284,32 +278,15 @@ QWeb.addDirective({
         }
       }
       let eventsCode = events
-        .map(function([eventName, mods, handlerValue, extraArgs]) {
-          let params = "context";
-          if (extraArgs) {
-            if (ctx.loopNumber) {
-              let argId = ctx.generateID();
-              // we need to evaluate the arguments now, because the handler will
-              // be set asynchronously later when the widget is ready, and the
-              // context might be different.
-              ctx.addLine(`let arg${argId} = ${ctx.formatExpression(extraArgs)};`);
-              params = `context, arg${argId}`;
-            } else {
-              params = `context, ${ctx.formatExpression(extraArgs)}`;
-            }
-          }
-          let handler = `function (e) {if(!context.__owl__.isMounted){return}`;
-          handler += mods
-            .map(function(mod) {
-              return T_COMPONENT_MODS_CODE[mod];
-            })
-            .join("");
-          if (handlerValue) {
-            handler += `const fn = context['${handlerValue}'];`;
-            handler += `if (fn) { fn.call(${params}, e); } else { context.${handlerValue}; }`;
-          }
-          handler += `}`;
-          return `vn.elm.addEventListener('${eventName}', ${handler});`;
+        .map(function([name, value]) {
+          const { event, handler } = makeHandlerCode(
+            ctx,
+            name,
+            value,
+            false,
+            T_COMPONENT_MODS_CODE
+          );
+          return `vn.elm.addEventListener('${event}', ${handler});`;
         })
         .join("");
       const styleExpr = tattStyle || (styleAttr ? `'${styleAttr}'` : false);

src/qweb/base_directives.ts

@@ -1,6 +1,7 @@
 import { CompilationContext } from "./compilation_context";
 import { QWeb } from "./qweb";
 import { htmlToVDOM } from "../vdom/html_to_vdom";
+import { QWebVar } from "./expression_parser";
 
 /**
  * Owl QWeb Directives
@@ -39,11 +40,11 @@ function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Compilatio
   let exprID: string;
   if (typeof value === "string") {
     exprID = `_${ctx.generateID()}`;
-    ctx.addLine(`var ${exprID} = ${ctx.formatExpression(value)};`);
+    ctx.addLine(`let ${exprID} = ${ctx.formatExpression(value)};`);
   } else {
     exprID = `scope.${value.id}`;
   }
-  ctx.addIf(`${exprID} || ${exprID} === 0`);
+  ctx.addIf(`${exprID} != null`);
 
   if (ctx.escaping) {
     let protectID;
@@ -61,7 +62,7 @@ function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Compilatio
       let nodeID = ctx.generateID();
       ctx.rootContext.rootNode = nodeID;
       ctx.rootContext.parentTextNode = nodeID;
-      ctx.addLine(`var vn${nodeID} = {text: ${exprID}};`);
+      ctx.addLine(`let vn${nodeID} = {text: ${exprID}};`);
       if (ctx.rootContext.shouldDefineResult) {
         ctx.addLine(`result = vn${nodeID}`);
       }
@@ -119,7 +120,7 @@ QWeb.addDirective({
     ctx.rootContext.shouldDefineScope = true;
     const variable = node.getAttribute("t-set")!;
     let value = node.getAttribute("t-value")!;
-    ctx.variables[variable] = ctx.variables[variable] || {};
+    ctx.variables[variable] = ctx.variables[variable] || ({} as QWebVar);
     let qwebvar = ctx.variables[variable];
     const hasBody = node.hasChildNodes();
 
@@ -140,7 +141,7 @@ QWeb.addDirective({
       const _parentNode = ctx.parentNode;
       ctx.parentNode = tempParentNodeID;
 
-      ctx.addLine(`const c${tempParentNodeID} = new utils.VDomArray();`);
+      ctx.addLine(`let c${tempParentNodeID} = new utils.VDomArray();`);
       const nodeCopy = node.cloneNode(true) as Element;
       for (let attr of ["t-set", "t-value", "t-if", "t-else", "t-elif"]) {
         nodeCopy.removeAttribute(attr);
@@ -215,6 +216,7 @@ QWeb.addDirective({
     // Step 1: sanity checks
     // ------------------------------------------------
     ctx.rootContext.shouldDefineScope = true;
+    ctx.rootContext.shouldDefineUtils = true;
     if (node.nodeName !== "t") {
       throw new Error("Invalid tag for t-call directive (should be 't')");
     }
@@ -228,7 +230,7 @@ QWeb.addDirective({
     // ------------------------------------------------
     if (!qweb.subTemplates[subTemplate]) {
       qweb.subTemplates[subTemplate] = true;
-      const subTemplateFn = qweb._compile(subTemplate, nodeTemplate.elem, ctx);
+      const subTemplateFn = qweb._compile(subTemplate, nodeTemplate.elem, ctx, true);
       qweb.subTemplates[subTemplate] = subTemplateFn;
     }
 
@@ -242,7 +244,9 @@ QWeb.addDirective({
       ctx.indent();
       protectID = ctx.startProtectScope();
       const nodeCopy = node.cloneNode(true) as Element;
-      nodeCopy.removeAttribute("t-call");
+      for (let attr of ["t-if", "t-else", "t-elif", "t-call"]) {
+        nodeCopy.removeAttribute(attr);
+      }
       const parentNode = ctx.parentNode;
       ctx.parentNode = "__0";
       // this local scope is intended to trap c__0
@@ -260,17 +264,17 @@ QWeb.addDirective({
     // Step 4: add the appropriate function call to current component
     // ------------------------------------------------
     const callingScope = hasBody ? "scope" : "Object.assign(Object.create(context), scope)";
+    const parentComponent = `utils.getComponent(context)`;
+    const keyCode = ctx.loopNumber || ctx.hasKey0 ? `, key: ${ctx.generateTemplateKey()}` : "";
+    const parentNode = ctx.parentNode ? `c${ctx.parentNode}` : "result";
+    const extra = `Object.assign({}, extra, {parentNode: ${parentNode}, parent: ${parentComponent}${keyCode}})`;
     if (ctx.parentNode) {
-      ctx.addLine(
-        `this.subTemplates['${subTemplate}'].call(this, ${callingScope}, Object.assign({}, extra, {parentNode: c${ctx.parentNode}}));`
-      );
+      ctx.addLine(`this.subTemplates['${subTemplate}'].call(this, ${callingScope}, ${extra});`);
     } else {
       // this is a t-call with no parentnode, we need to extract the result
       ctx.rootContext.shouldDefineResult = true;
       ctx.addLine(`result = []`);
-      ctx.addLine(
-        `this.subTemplates['${subTemplate}'].call(this, ${callingScope}, Object.assign({}, extra, {parentNode: result}));`
-      );
+      ctx.addLine(`this.subTemplates['${subTemplate}'].call(this, ${callingScope}, ${extra});`);
       ctx.addLine(`result = result[0]`);
     }
 
@@ -299,16 +303,16 @@ QWeb.addDirective({
     const elems = node.getAttribute("t-foreach")!;
     const name = node.getAttribute("t-as")!;
     let arrayID = ctx.generateID();
-    ctx.addLine(`var _${arrayID} = ${ctx.formatExpression(elems)};`);
+    ctx.addLine(`let _${arrayID} = ${ctx.formatExpression(elems)};`);
     ctx.addLine(`if (!_${arrayID}) { throw new Error('QWeb error: Invalid loop expression')}`);
     let keysID = ctx.generateID();
     let valuesID = ctx.generateID();
-    ctx.addLine(`var _${keysID} = _${valuesID} = _${arrayID};`);
+    ctx.addLine(`let _${keysID} = _${valuesID} = _${arrayID};`);
     ctx.addIf(`!(_${arrayID} instanceof Array)`);
     ctx.addLine(`_${keysID} = Object.keys(_${arrayID});`);
     ctx.addLine(`_${valuesID} = Object.values(_${arrayID});`);
     ctx.closeIf();
-    ctx.addLine(`var _length${keysID} = _${keysID}.length;`);
+    ctx.addLine(`let _length${keysID} = _${keysID}.length;`);
     let varsID = ctx.startProtectScope();
     const loopVar = `i${ctx.loopNumber}`;
     ctx.addLine(`for (let ${loopVar} = 0; ${loopVar} < _length${keysID}; ${loopVar}++) {`);
@@ -330,6 +334,13 @@ QWeb.addDirective({
         `Directive t-foreach should always be used with a t-key! (in template: '${ctx.templateName}')`
       );
     }
+    if (nodeCopy.hasAttribute("t-key")) {
+      const expr = ctx.formatExpression(nodeCopy.getAttribute("t-key")!);
+      ctx.addLine(`let key${ctx.loopNumber} = ${expr};`);
+      nodeCopy.removeAttribute("t-key");
+    } else {
+      ctx.addLine(`let key${ctx.loopNumber} = i${ctx.loopNumber};`);
+    }
 
     nodeCopy.removeAttribute("t-foreach");
     qweb._compileNode(nodeCopy, ctx);

src/qweb/compilation_context.ts

@@ -26,12 +26,13 @@ export class CompilationContext {
   templateName: string;
   allowMultipleRoots: boolean = false;
   hasParentWidget: boolean = false;
-  currentKey: string = "";
+  hasKey0: boolean = false;
+  keyStack: boolean[] = [];
 
   constructor(name?: string) {
     this.rootContext = this;
     this.templateName = name || "noname";
-    this.addLine("var h = this.h;");
+    this.addLine("let h = this.h;");
   }
 
   generateID(): number {
@@ -46,19 +47,17 @@ export class CompilationContext {
    * Such a key is necessary when we need to associate an id to some element
    * generated by a template (for example, a component)
    */
-  generateTemplateKey(): string {
+  generateTemplateKey(prefix: string = ""): string {
     const id = this.generateID();
-    let locationExpr = `\`__${this.generateID()}__`;
-    for (let i = 0; i < this.loopNumber - 1; i++) {
-      locationExpr += `\${i${i + 1}}__`;
+    if (this.loopNumber === 0 && !this.hasKey0) {
+      return `'${prefix}__${id}__'`;
     }
-    if (this.currentKey) {
-      const k = this.currentKey;
-      this.addLine(`let k${id} = ${locationExpr}\` + ${k};`);
-    } else {
-      locationExpr += this.loopNumber ? `\${i${this.loopNumber}}__\`` : "`";
-      this.addLine(`let k${id} = ${locationExpr};`);
+    let key = `\`${prefix}__${id}__`;
+    let start = this.hasKey0 ? 0 : 1;
+    for (let i = start; i < this.loopNumber + 1; i++) {
+      key += `\${key${i}}__`;
     }
+    this.addLine(`let k${id} = ${key}\`;`);
     return `k${id}`;
   }
 
@@ -113,11 +112,11 @@ export class CompilationContext {
   }
 
   indent() {
-    this.indentLevel++;
+    this.rootContext.indentLevel++;
   }
 
   dedent() {
-    this.indentLevel--;
+    this.rootContext.indentLevel--;
   }
 
   addLine(line: string): number {
@@ -177,7 +176,7 @@ export class CompilationContext {
   startProtectScope(): number {
     const protectID = this.generateID();
     this.rootContext.shouldDefineScope = true;
-    this.addLine(`const _origScope${protectID} = scope;`);
+    this.addLine(`let _origScope${protectID} = scope;`);
     this.addLine(`scope = Object.assign(Object.create(context), scope);`);
     return protectID;
   }

src/qweb/expression_parser.ts

@@ -81,7 +81,7 @@ const STATIC_TOKEN_MAP: { [key: string]: TKind } = {
 
 // note that the space after typeof is relevant. It makes sure that the formatted
 // expression has a space after typeof
-const OPERATORS = ".,===,==,+,!==,!=,!,||,&&,>=,>,<=,<,?,-,*,/,%,typeof ,=>".split(",");
+const OPERATORS = "...,.,===,==,+,!==,!=,!,||,&&,>=,>,<=,<,?,-,*,/,%,typeof ,=>,=,;".split(",");
 
 type Tokenizer = (expr: string) => Token | false;
 

src/qweb/extensions.ts

@@ -26,48 +26,66 @@ export const MODS_CODE = {
   stop: "e.stopPropagation();"
 };
 
+interface HandlerInfo {
+  event: string;
+  handler: string;
+}
+
+const FNAMEREGEXP = /^[$A-Z_][0-9A-Z_$]*$/i;
+
+export function makeHandlerCode(
+  ctx,
+  fullName,
+  value,
+  putInCache: boolean,
+  modcodes = MODS_CODE
+): HandlerInfo {
+  const [event, ...mods] = fullName.slice(5).split(".");
+  if (!event) {
+    throw new Error("Missing event name with t-on directive");
+  }
+  let code: string;
+  // check if it is a method with no args, a method with args or an expression
+  let args: string = "";
+  const name: string = value.replace(/\(.*\)/, function(_args) {
+    args = _args.slice(1, -1);
+    return "";
+  });
+  const isMethodCall = name.match(FNAMEREGEXP);
+
+  // then generate code
+  if (isMethodCall) {
+    ctx.rootContext.shouldDefineUtils = true;
+    const comp = `utils.getComponent(context)`;
+    if (args) {
+      let argId = ctx.generateID();
+      ctx.addLine(`let args${argId} = [${ctx.formatExpression(args)}];`);
+      code = `${comp}['${name}'](...args${argId}, e);`;
+      putInCache = false;
+    } else {
+      code = `${comp}['${name}'](e);`;
+    }
+  } else {
+    // if we get here, then it is an expression
+    putInCache = false;
+    code = ctx.formatExpression(value);
+  }
+  const modCode = mods.map(mod => modcodes[mod]).join("");
+  let handler = `function (e) {if (!context.__owl__.isMounted){return}${modCode}${code}}`;
+  if (putInCache) {
+    const key = ctx.generateTemplateKey(event);
+    ctx.addLine(`extra.handlers[${key}] = extra.handlers[${key}] || ${handler};`);
+    handler = `extra.handlers[${key}]`;
+  }
+  return { event, handler };
+}
+
 QWeb.addDirective({
   name: "on",
   priority: 90,
   atNodeCreation({ ctx, fullName, value, nodeID }) {
-    const [eventName, ...mods] = fullName.slice(5).split(".");
-    if (!eventName) {
-      throw new Error("Missing event name with t-on directive");
-    }
-    let extraArgs;
-    let handlerName = value.replace(/\(.*\)/, function(args) {
-      extraArgs = args.slice(1, -1);
-      return "";
-    });
-    let params = extraArgs ? `context, ${ctx.formatExpression(extraArgs)}` : "context";
-    let handler = `function (e) {if (!context.__owl__.isMounted){return}`;
-    handler += mods
-      .map(function(mod) {
-        return MODS_CODE[mod];
-      })
-      .join("");
-    if (handlerName) {
-      if (!extraArgs) {
-        handler += `const fn = context['${handlerName}'];`;
-        handler += `if (fn) { fn.call(${params}, e); } else { context.${handlerName}; }`;
-        handler += `}`;
-        ctx.addLine(
-          `extra.handlers['${eventName}' + ${nodeID}] = extra.handlers['${eventName}' + ${nodeID}] || ${handler};`
-        );
-        ctx.addLine(`p${nodeID}.on['${eventName}'] = extra.handlers['${eventName}' + ${nodeID}];`);
-      } else {
-        const handlerKey = `handler${ctx.generateID()}`;
-        ctx.addLine(
-          `const ${handlerKey} = context['${handlerName}'] && context['${handlerName}'].bind(${params});`
-        );
-        handler += `if (${handlerKey}) { ${handlerKey}(e); } else { context.${value}; }`;
-        handler += `}`;
-        ctx.addLine(`p${nodeID}.on['${eventName}'] = ${handler};`);
-      }
-    } else {
-      handler += "}";
-      ctx.addLine(`p${nodeID}.on['${eventName}'] = ${handler};`);
-    }
+    const { event, handler } = makeHandlerCode(ctx, fullName, value, true);
+    ctx.addLine(`p${nodeID}.on['${event}'] = ${handler};`);
   }
 });
 
@@ -285,9 +303,20 @@ QWeb.addDirective({
 QWeb.addDirective({
   name: "key",
   priority: 45,
-  atNodeEncounter({ ctx, value }) {
-    let id = ctx.generateID();
-    ctx.addLine(`const nodeKey${id} = ${ctx.formatExpression(value)};`);
-    ctx.currentKey = `nodeKey${id}`;
+  atNodeEncounter({ ctx, value, node }) {
+    if (ctx.loopNumber === 0) {
+      ctx.keyStack.push(ctx.rootContext.hasKey0);
+      ctx.rootContext.hasKey0 = true;
+    }
+    ctx.addLine("{");
+    ctx.indent();
+    ctx.addLine(`let key${ctx.loopNumber} = ${ctx.formatExpression(value)};`);
+  },
+  finalize({ ctx }) {
+    ctx.dedent();
+    ctx.addLine("}");
+    if (ctx.loopNumber === 0) {
+      ctx.rootContext.hasKey0 = ctx.keyStack.pop() as boolean;
+    }
   }
 });

src/qweb/qweb.ts

@@ -1,7 +1,7 @@
 import { EventBus } from "../core/event_bus";
 import { h, patch, VNode } from "../vdom/index";
 import { CompilationContext } from "./compilation_context";
-import { shallowEqual } from "../utils";
+import { shallowEqual, escape } from "../utils";
 import { addNS } from "../vdom/vdom";
 
 /**
@@ -119,7 +119,13 @@ const UTILS: Utils = {
           return vnode.text;
         }
       })
-      .join();
+      .join("");
+  },
+  getComponent(obj) {
+    while (obj && !obj.hasOwnProperty("__owl__")) {
+      obj = obj.__proto__;
+    }
+    return obj;
   }
 };
 
@@ -348,8 +354,17 @@ export class QWeb extends EventBus {
       return vnode.text!;
     }
     const node = document.createElement(vnode.sel);
-    const result = patch(node, vnode);
-    return (<HTMLElement>result.elm).outerHTML;
+    const elem = patch(node, vnode).elm as HTMLElement;
+    function escapeTextNodes(node) {
+      if (node.nodeType === 3) {
+        node.textContent = escape(node.textContent);
+      }
+      for (let n of node.childNodes) {
+        escapeTextNodes(n);
+      }
+    }
+    escapeTextNodes(elem);
+    return elem.outerHTML;
   }
 
   /**
@@ -368,7 +383,12 @@ export class QWeb extends EventBus {
     });
   }
 
-  _compile(name: string, elem: Element, parentContext?: CompilationContext): CompiledTemplate {
+  _compile(
+    name: string,
+    elem: Element,
+    parentContext?: CompilationContext,
+    defineKey?: boolean
+  ): CompiledTemplate {
     const isDebug = elem.attributes.hasOwnProperty("t-debug");
     const ctx = new CompilationContext(name);
     if (elem.tagName !== "t") {
@@ -381,6 +401,10 @@ export class QWeb extends EventBus {
       ctx.hasParentWidget = true;
       ctx.shouldDefineResult = false;
       ctx.addLine(`let c${ctx.parentNode} = extra.parentNode;`);
+      if (defineKey) {
+        ctx.addLine(`let key0 = extra.key || "";`);
+        ctx.hasKey0 = true;
+      }
     }
     this._compileNode(elem, ctx);
 
@@ -451,16 +475,13 @@ export class QWeb extends EventBus {
         // this is an unusual situation: this text node is the result of the
         // template rendering.
         let nodeID = ctx.generateID();
-        ctx.addLine(`var vn${nodeID} = {text: \`${text}\`};`);
+        ctx.addLine(`let vn${nodeID} = {text: \`${text}\`};`);
         ctx.addLine(`result = vn${nodeID};`);
         ctx.rootContext.rootNode = nodeID;
         ctx.rootContext.parentTextNode = nodeID;
       }
       return;
     }
-    if (ctx !== ctx.rootContext) {
-      ctx = ctx.subContext("currentKey", ctx.currentKey);
-    }
 
     const firstLetter = node.tagName[0];
     if (firstLetter === firstLetter.toUpperCase()) {
@@ -663,7 +684,7 @@ export class QWeb extends EventBus {
             ctx.addLine(`let ${classObj} = {${classDef}};`);
           }
         } else {
-          ctx.addLine(`var _${attID} = '${value}';`);
+          ctx.addLine(`let _${attID} = '${value}';`);
           if (!name.match(/^[a-zA-Z]+$/)) {
             // attribute contains 'non letters' => we want to quote it
             name = '"' + name + '"';
@@ -699,12 +720,12 @@ export class QWeb extends EventBus {
           const attValue = (<Element>node).getAttribute(attName);
           if (attValue) {
             const attValueID = ctx.generateID();
-            ctx.addLine(`var _${attValueID} = ${formattedValue};`);
+            ctx.addLine(`let _${attValueID} = ${formattedValue};`);
             formattedValue = `'${attValue}' + (_${attValueID} ? ' ' + _${attValueID} : '')`;
             const attrIndex = attrs.findIndex(att => att.startsWith(attName + ":"));
             attrs.splice(attrIndex, 1);
           }
-          ctx.addLine(`var _${attID} = ${formattedValue};`);
+          ctx.addLine(`let _${attID} = ${formattedValue};`);
           attrs.push(`${attName}: _${attID}`);
           handleBooleanProps(attName, attID);
         }
@@ -720,9 +741,9 @@ export class QWeb extends EventBus {
         const attID = ctx.generateID();
         let staticVal = (<Element>node).getAttribute(attName);
         if (staticVal) {
-          ctx.addLine(`var _${attID} = '${staticVal} ' + ${formattedExpr};`);
+          ctx.addLine(`let _${attID} = '${staticVal} ' + ${formattedExpr};`);
         } else {
-          ctx.addLine(`var _${attID} = ${formattedExpr};`);
+          ctx.addLine(`let _${attID} = ${formattedExpr};`);
         }
         attrs.push(`${attName}: _${attID}`);
       }
@@ -730,13 +751,13 @@ export class QWeb extends EventBus {
       // t-att= attributes
       if (name === "t-att") {
         let id = ctx.generateID();
-        ctx.addLine(`var _${id} = ${ctx.formatExpression(value!)};`);
+        ctx.addLine(`let _${id} = ${ctx.formatExpression(value!)};`);
         tattrs.push(id);
       }
     }
     let nodeID = ctx.generateID();
-    let nodeKey = ctx.currentKey || nodeID;
-    const parts = [`key:${nodeKey}`];
+    let key = ctx.loopNumber || ctx.hasKey0 ? `\`\${key${ctx.loopNumber}}_${nodeID}\`` : nodeID;
+    const parts = [`key:${key}`];
     if (attrs.length + tattrs.length > 0) {
       parts.push(`attrs:{${attrs.join(",")}}`);
     }
@@ -762,9 +783,12 @@ export class QWeb extends EventBus {
       ctx.addLine(`}`);
       ctx.closeIf();
     }
-    ctx.addLine(`var vn${nodeID} = h('${node.nodeName}', p${nodeID}, c${nodeID});`);
+    ctx.addLine(`let vn${nodeID} = h('${node.nodeName}', p${nodeID}, c${nodeID});`);
     if (ctx.parentNode) {
       ctx.addLine(`c${ctx.parentNode}.push(vn${nodeID});`);
+    } else if (ctx.loopNumber || ctx.hasKey0) {
+      ctx.rootContext.shouldDefineResult = true;
+      ctx.addLine(`result = vn${nodeID};`);
     }
 
     return nodeID;

src/store.ts

@@ -141,6 +141,9 @@ export function useStore(selector, options: SelectorOptions = {}): any {
     },
     set(target, k, v) {
       throw new Error("Store state should only be modified through actions");
+    },
+    has(target, k) {
+      return k in result;
     }
   });
 }

src/utils.ts

@@ -58,12 +58,9 @@ export function escape(str: string | number | undefined): string {
   if (typeof str === "number") {
     return String(str);
   }
-  return str
-    .replace(/&/g, "&")
-    .replace(/</g, "&lt;")
-    .replace(/>/g, "&gt;")
-    .replace(/"/g, "&#x27;")
-    .replace(/`/g, "&#x60;");
+  const p = document.createElement("p");
+  p.textContent = str;
+  return p.innerHTML;
 }
 
 /**

tests/__snapshots__/animations.test.ts.snap

@@ -8,12 +8,11 @@ exports[`animations t-transition combined with component 1`] = `
     let QWeb = this.constructor;
     let parent = context;
     let scope = Object.create(context);
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('div', p1, c1);
-    //COMPONENT
-    let k3 = \`__4__\`;
-    let w2 = k3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k3]] : false;
+    let vn1 = h('div', p1, c1);
+    // Component 'Child'
+    let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
     let props2 = {};
     if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
         w2.destroy();
@@ -30,9 +29,9 @@ exports[`animations t-transition combined with component 1`] = `
         w2 = new W2(parent, props2);
         const __patch2 = w2.__patch;
         w2.__patch = fiber => {__patch2.call(w2, fiber); if(!w2.__owl__.transitionInserted){w2.__owl__.transitionInserted = true;utils.transitionInsert(w2.__owl__.vnode, 'chimay');}};
-        parent.__owl__.cmap[k3] = w2.__owl__.id;
+        parent.__owl__.cmap['__3__'] = w2.__owl__.id;
         let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-        let pvnode = h('dummy', {key: k3, hook: {remove() {},destroy(vn) {let finalize = () => {
+        let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {let finalize = () => {
           w2.destroy();
         };
         delete w2.__owl__.transitionInserted;
@@ -53,13 +52,12 @@ exports[`animations t-transition combined with t-component and t-if 1`] = `
     let QWeb = this.constructor;
     let parent = context;
     let scope = Object.create(context);
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('div', p1, c1);
+    let vn1 = h('div', p1, c1);
     if (scope['state'].display) {
-        //COMPONENT
-        let k3 = \`__4__\`;
-        let w2 = k3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k3]] : false;
+        // Component 'Child'
+        let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
         let props2 = {};
         if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
             w2.destroy();
@@ -76,9 +74,9 @@ exports[`animations t-transition combined with t-component and t-if 1`] = `
             w2 = new W2(parent, props2);
             const __patch2 = w2.__patch;
             w2.__patch = fiber => {__patch2.call(w2, fiber); if(!w2.__owl__.transitionInserted){w2.__owl__.transitionInserted = true;utils.transitionInsert(w2.__owl__.vnode, 'chimay');}};
-            parent.__owl__.cmap[k3] = w2.__owl__.id;
+            parent.__owl__.cmap['__3__'] = w2.__owl__.id;
             let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-            let pvnode = h('dummy', {key: k3, hook: {remove() {},destroy(vn) {let finalize = () => {
+            let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {let finalize = () => {
           w2.destroy();
         };
         delete w2.__owl__.transitionInserted;
@@ -100,13 +98,12 @@ exports[`animations t-transition combined with t-component, remove and re-add be
     let QWeb = this.constructor;
     let parent = context;
     let scope = Object.create(context);
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('div', p1, c1);
+    let vn1 = h('div', p1, c1);
     if (scope['state'].flag) {
-        //COMPONENT
-        let k3 = \`__4__\`;
-        let w2 = k3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k3]] : false;
+        // Component 'Child'
+        let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
         let props2 = {};
         if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
             w2.destroy();
@@ -123,9 +120,9 @@ exports[`animations t-transition combined with t-component, remove and re-add be
             w2 = new W2(parent, props2);
             const __patch2 = w2.__patch;
             w2.__patch = fiber => {__patch2.call(w2, fiber); if(!w2.__owl__.transitionInserted){w2.__owl__.transitionInserted = true;utils.transitionInsert(w2.__owl__.vnode, 'chimay');}};
-            parent.__owl__.cmap[k3] = w2.__owl__.id;
+            parent.__owl__.cmap['__3__'] = w2.__owl__.id;
             let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-            let pvnode = h('dummy', {key: k3, hook: {remove() {},destroy(vn) {let finalize = () => {
+            let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {let finalize = () => {
           w2.destroy();
         };
         delete w2.__owl__.transitionInserted;
@@ -144,9 +141,9 @@ exports[`animations t-transition with no delay/duration 1`] = `
 ) {
     // Template name: \\"test\\"
     let utils = this.constructor.utils;
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('span', p1, c1);
+    let vn1 = h('span', p1, c1);
     p1.hook = {
       insert: vn => {
         utils.transitionInsert(vn, 'jupiler');
@@ -165,9 +162,9 @@ exports[`animations t-transition, on a simple node (insert) 1`] = `
 ) {
     // Template name: \\"test\\"
     let utils = this.constructor.utils;
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('span', p1, c1);
+    let vn1 = h('span', p1, c1);
     p1.hook = {
       insert: vn => {
         utils.transitionInsert(vn, 'chimay');

tests/animations.test.ts

@@ -254,11 +254,11 @@ describe("animations", () => {
     widget.state.display = false;
     patchNextFrame(cb => {
       expect(fixture.innerHTML).toBe(
-        '<div><span class="chimay-leave chimay-leave-active" data-owl-key="__4__">blue</span></div>'
+        '<div><span class="chimay-leave chimay-leave-active" data-owl-key="__3__">blue</span></div>'
       );
       cb();
       expect(fixture.innerHTML).toBe(
-        '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="__4__">blue</span></div>'
+        '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="__3__">blue</span></div>'
       );
       def.resolve();
     });
@@ -371,7 +371,7 @@ describe("animations", () => {
 
     await def; // wait for the mocked repaint to be done
     widget.el!.querySelector("span")!.dispatchEvent(new Event("transitionend")); // mock end of css transition
-    expect(fixture.innerHTML).toBe('<div><span class="" data-owl-key="__4__">blue</span></div>');
+    expect(fixture.innerHTML).toBe('<div><span class="" data-owl-key="__3__">blue</span></div>');
   });
 
   test("transitionInsert is called the correct amount of times", async () => {
@@ -405,14 +405,14 @@ describe("animations", () => {
     widget.state.flag = false;
     await nextTick();
     expect(fixture.innerHTML).toBe(
-      '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="__4__">blue</span></div>'
+      '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="__3__">blue</span></div>'
     );
     expect(QWeb.utils.transitionInsert).toBeCalledTimes(1);
 
     widget.state.flag = true;
     await nextTick();
     expect(fixture.innerHTML).toBe(
-      '<div><span class="chimay-enter-active chimay-enter-to" data-owl-key="__4__">blue</span></div>'
+      '<div><span class="chimay-enter-active chimay-enter-to" data-owl-key="__3__">blue</span></div>'
     );
     expect(QWeb.utils.transitionInsert).toBeCalledTimes(2);
 
@@ -423,7 +423,7 @@ describe("animations", () => {
 
     expect(QWeb.utils.transitionInsert).toBeCalledTimes(3);
     widget.el!.querySelector("span")!.dispatchEvent(new Event("transitionend"));
-    expect(fixture.innerHTML).toBe('<div><span class="" data-owl-key="__4__">blue</span></div>');
+    expect(fixture.innerHTML).toBe('<div><span class="" data-owl-key="__3__">blue</span></div>');
     QWeb.utils.transitionInsert = oldTransitionInsert;
   });
 });

tests/component/__snapshots__/props_validation.test.ts.snap

@@ -8,12 +8,11 @@ exports[`props validation props are validated in dev mode (code snapshot) 1`] =
     let QWeb = this.constructor;
     let parent = context;
     let scope = Object.create(context);
-    var h = this.h;
+    let h = this.h;
     let c1 = [], p1 = {key:1};
-    var vn1 = h('div', p1, c1);
-    //COMPONENT
-    let k3 = \`__4__\`;
-    let w2 = k3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k3]] : false;
+    let vn1 = h('div', p1, c1);
+    // Component 'Child'
+    let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
     let props2 = {message:1};
     if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
         w2.destroy();
@@ -28,9 +27,9 @@ exports[`props validation props are validated in dev mode (code snapshot) 1`] =
         let W2 = context.constructor.components[componentKey2] || QWeb.components[componentKey2]|| scope['Child'];
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
-        parent.__owl__.cmap[k3] = w2.__owl__.id;
+        parent.__owl__.cmap['__3__'] = w2.__owl__.id;
         let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-        let pvnode = h('dummy', {key: k3, hook: {remove() {},destroy(vn) {w2.destroy();}}});
+        let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
     }

tests/component/__snapshots__/slots.test.ts.snap

@@ -0,0 +1,488 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`t-slot directive can define and call slots 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"Parent\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    // Component 'Dialog'
+    let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
+    let props2 = {};
+    if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
+        w2.destroy();
+        w2 = false;
+    }
+    if (w2) {
+        w2.__updateProps(props2, extra.fiber, Object.assign(Object.create(context), scope));
+        let pvnode = w2.__owl__.pvnode;
+        c1.push(pvnode);
+    } else {
+        let componentKey2 = \`Dialog\`;
+        let W2 = context.constructor.components[componentKey2] || QWeb.components[componentKey2]|| scope['Dialog'];
+        if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
+        w2 = new W2(parent, props2);
+        parent.__owl__.cmap['__3__'] = w2.__owl__.id;
+        w2.__owl__.slotId = 1;
+        let fiber = w2.__prepare(extra.fiber, Object.assign(Object.create(context), scope), () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+        let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
+        c1.push(pvnode);
+        w2.__owl__.pvnode = pvnode;
+    }
+    w2.__owl__.parentLastFiberId = extra.fiber.id;
+    return vn1;
+}"
+`;
+
+exports[`t-slot directive can define and call slots 2`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"Dialog\\"
+    let h = this.h;
+    let c6 = [], p6 = {key:6};
+    let vn6 = h('div', p6, c6);
+    let c7 = [], p7 = {key:7};
+    let vn7 = h('div', p7, c7);
+    c6.push(vn7);
+    const slot8 = this.constructor.slots[context.__owl__.slotId + '_' + 'header'];
+    if (slot8) {
+        slot8.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c7, parent: extra.parent || context}));
+    }
+    let c9 = [], p9 = {key:9};
+    let vn9 = h('div', p9, c9);
+    c6.push(vn9);
+    const slot10 = this.constructor.slots[context.__owl__.slotId + '_' + 'footer'];
+    if (slot10) {
+        slot10.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c9, parent: extra.parent || context}));
+    }
+    return vn6;
+}"
+`;
+
+exports[`t-slot directive can define and call slots 3`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_header_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    c1.push(vn4);
+    c4.push({text: \`header\`});
+}"
+`;
+
+exports[`t-slot directive can define and call slots 4`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_footer_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('span', p5, c5);
+    c1.push(vn5);
+    c5.push({text: \`footer\`});
+}"
+`;
+
+exports[`t-slot directive content is the default slot 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    c1.push(vn4);
+    c4.push({text: \`sts rocks\`});
+}"
+`;
+
+exports[`t-slot directive dafault slots can define a default content 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    let h = this.h;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    const slot5 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
+    if (slot5) {
+        slot5.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c4, parent: extra.parent || context}));
+    } else {
+        c4.push({text: \`default content\`});
+    }
+    return vn4;
+}"
+`;
+
+exports[`t-slot directive default slot work with text nodes 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    c1.push({text: \`sts rocks\`});
+}"
+`;
+
+exports[`t-slot directive multiple roots are allowed in a default slot 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    c1.push(vn4);
+    c4.push({text: \`sts\`});
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('span', p5, c5);
+    c1.push(vn5);
+    c5.push({text: \`rocks\`});
+}"
+`;
+
+exports[`t-slot directive multiple roots are allowed in a named slot 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_content_template\\"
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    c1.push(vn4);
+    c4.push({text: \`sts\`});
+    let c5 = [], p5 = {key:5};
+    let vn5 = h('span', p5, c5);
+    c1.push(vn5);
+    c5.push({text: \`rocks\`});
+}"
+`;
+
+exports[`t-slot directive named slots can define a default content 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__1\\"
+    let h = this.h;
+    let c4 = [], p4 = {key:4};
+    let vn4 = h('span', p4, c4);
+    const slot5 = this.constructor.slots[context.__owl__.slotId + '_' + 'header'];
+    if (slot5) {
+        slot5.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c4, parent: extra.parent || context}));
+    } else {
+        c4.push({text: \`default content\`});
+    }
+    return vn4;
+}"
+`;
+
+exports[`t-slot directive refs are properly bound in slots 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_footer_template\\"
+    let utils = this.constructor.utils;
+    context.__owl__.refs = context.__owl__.refs || {};
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c8 = [], p8 = {key:8,on:{}};
+    let vn8 = h('button', p8, c8);
+    c1.push(vn8);
+    extra.handlers['click__9__'] = extra.handlers['click__9__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);};
+    p8.on['click'] = extra.handlers['click__9__'];
+    const ref10 = \`myButton\`;
+    p8.hook = {
+      create: (_, n) => {
+        context.__owl__.refs[ref10] = n.elm;
+      },
+      destroy: () => {
+        delete context.__owl__.refs[ref10];
+      },
+    };
+    c8.push({text: \`do something\`});
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_footer_template\\"
+    let utils = this.constructor.utils;
+    let h = this.h;
+    let c1 = extra.parentNode;
+    let c8 = [], p8 = {key:8,on:{}};
+    let vn8 = h('button', p8, c8);
+    c1.push(vn8);
+    extra.handlers['click__9__'] = extra.handlers['click__9__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);};
+    p8.on['click'] = extra.handlers['click__9__'];
+    c8.push({text: \`do something\`});
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 2 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"Link\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let _11 = scope['props'].to;
+    let c12 = [], p12 = {key:12,attrs:{href: _11}};
+    let vn12 = h('a', p12, c12);
+    const slot13 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
+    if (slot13) {
+        slot13.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c12, parent: extra.parent || context}));
+    }
+    return vn12;
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 2 2`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"App\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('u', p2, c2);
+    c1.push(vn2);
+    let _3 = scope['state'].users;
+    if (!_3) { throw new Error('QWeb error: Invalid loop expression')}
+    let _4 = _5 = _3;
+    if (!(_3 instanceof Array)) {
+        _4 = Object.keys(_3);
+        _5 = Object.values(_3);
+    }
+    let _length4 = _4.length;
+    let _origScope6 = scope;
+    scope = Object.assign(Object.create(context), scope);
+    for (let i1 = 0; i1 < _length4; i1++) {
+        scope.user_first = i1 === 0
+        scope.user_last = i1 === _length4 - 1
+        scope.user_index = i1
+        scope.user = _4[i1]
+        scope.user_value = _5[i1]
+        let key1 = scope['user'].id;
+        let c7 = [], p7 = {key:\`\${key1}_7\`};
+        let vn7 = h('li', p7, c7);
+        c2.push(vn7);
+        // Component 'Link'
+        let k9 = \`__9__\${key1}__\`;
+        let w8 = k9 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k9]] : false;
+        let props8 = {to:'/user/'+scope['user'].id};
+        if (w8 && w8.__owl__.currentFiber && !w8.__owl__.vnode) {
+            w8.destroy();
+            w8 = false;
+        }
+        if (w8) {
+            w8.__updateProps(props8, extra.fiber, Object.assign(Object.create(context), scope));
+            let pvnode = w8.__owl__.pvnode;
+            c7.push(pvnode);
+        } else {
+            let componentKey8 = \`Link\`;
+            let W8 = context.constructor.components[componentKey8] || QWeb.components[componentKey8]|| scope['Link'];
+            if (!W8) {throw new Error('Cannot find the definition of component \\"' + componentKey8 + '\\"')}
+            w8 = new W8(parent, props8);
+            parent.__owl__.cmap[k9] = w8.__owl__.id;
+            w8.__owl__.slotId = 1;
+            let fiber = w8.__prepare(extra.fiber, Object.assign(Object.create(context), scope), () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+            let pvnode = h('dummy', {key: k9, hook: {remove() {},destroy(vn) {w8.destroy();}}});
+            c7.push(pvnode);
+            w8.__owl__.pvnode = pvnode;
+        }
+        w8.__owl__.parentLastFiberId = extra.fiber.id;
+    }
+    scope = _origScope6;
+    return vn1;
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 2 3`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let c7 = extra.parentNode;
+    c7.push({text: \`User \`});
+    let _10 = scope['user'].name;
+    if (_10 != null) {
+        c7.push({text: _10});
+    }
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 3 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"Link\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let _10 = scope['props'].to;
+    let c11 = [], p11 = {key:11,attrs:{href: _10}};
+    let vn11 = h('a', p11, c11);
+    const slot12 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
+    if (slot12) {
+        slot12.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c11, parent: extra.parent || context}));
+    }
+    return vn11;
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 3 2`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"App\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    let c2 = [], p2 = {key:2};
+    let vn2 = h('u', p2, c2);
+    c1.push(vn2);
+    let _3 = scope['state'].users;
+    if (!_3) { throw new Error('QWeb error: Invalid loop expression')}
+    let _4 = _5 = _3;
+    if (!(_3 instanceof Array)) {
+        _4 = Object.keys(_3);
+        _5 = Object.values(_3);
+    }
+    let _length4 = _4.length;
+    let _origScope6 = scope;
+    scope = Object.assign(Object.create(context), scope);
+    for (let i1 = 0; i1 < _length4; i1++) {
+        scope.user_first = i1 === 0
+        scope.user_last = i1 === _length4 - 1
+        scope.user_index = i1
+        scope.user = _4[i1]
+        scope.user_value = _5[i1]
+        let key1 = scope['user'].id;
+        let c7 = [], p7 = {key:\`\${key1}_7\`};
+        let vn7 = h('li', p7, c7);
+        c2.push(vn7);
+        scope.userdescr = 'User '+scope['user'].name;
+        // Component 'Link'
+        let k9 = \`__9__\${key1}__\`;
+        let w8 = k9 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k9]] : false;
+        let props8 = {to:'/user/'+scope['user'].id};
+        if (w8 && w8.__owl__.currentFiber && !w8.__owl__.vnode) {
+            w8.destroy();
+            w8 = false;
+        }
+        if (w8) {
+            w8.__updateProps(props8, extra.fiber, Object.assign(Object.create(context), scope));
+            let pvnode = w8.__owl__.pvnode;
+            c7.push(pvnode);
+        } else {
+            let componentKey8 = \`Link\`;
+            let W8 = context.constructor.components[componentKey8] || QWeb.components[componentKey8]|| scope['Link'];
+            if (!W8) {throw new Error('Cannot find the definition of component \\"' + componentKey8 + '\\"')}
+            w8 = new W8(parent, props8);
+            parent.__owl__.cmap[k9] = w8.__owl__.id;
+            w8.__owl__.slotId = 1;
+            let fiber = w8.__prepare(extra.fiber, Object.assign(Object.create(context), scope), () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+            let pvnode = h('dummy', {key: k9, hook: {remove() {},destroy(vn) {w8.destroy();}}});
+            c7.push(pvnode);
+            w8.__owl__.pvnode = pvnode;
+        }
+        w8.__owl__.parentLastFiberId = extra.fiber.id;
+    }
+    scope = _origScope6;
+    return vn1;
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 3 3`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let c7 = extra.parentNode;
+    if (scope.userdescr != null) {
+        c7.push({text: scope.userdescr});
+    }
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 4 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"App\\"
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    scope.userdescr = 'User '+scope['state'].user.name;
+    // Component 'Link'
+    let w2 = '__3__' in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap['__3__']] : false;
+    let props2 = {to:'/user/'+scope['state'].user.id};
+    if (w2 && w2.__owl__.currentFiber && !w2.__owl__.vnode) {
+        w2.destroy();
+        w2 = false;
+    }
+    if (w2) {
+        w2.__updateProps(props2, extra.fiber, Object.assign(Object.create(context), scope));
+        let pvnode = w2.__owl__.pvnode;
+        c1.push(pvnode);
+    } else {
+        let componentKey2 = \`Link\`;
+        let W2 = context.constructor.components[componentKey2] || QWeb.components[componentKey2]|| scope['Link'];
+        if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
+        w2 = new W2(parent, props2);
+        parent.__owl__.cmap['__3__'] = w2.__owl__.id;
+        w2.__owl__.slotId = 1;
+        let fiber = w2.__prepare(extra.fiber, Object.assign(Object.create(context), scope), () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+        let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
+        c1.push(pvnode);
+        w2.__owl__.pvnode = pvnode;
+    }
+    w2.__owl__.parentLastFiberId = extra.fiber.id;
+    return vn1;
+}"
+`;
+
+exports[`t-slot directive slots are rendered with proper context, part 4 2`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"slot_default_template\\"
+    let scope = Object.create(context);
+    let h = this.h;
+    let c1 = extra.parentNode;
+    if (scope.userdescr != null) {
+        c1.push({text: scope.userdescr});
+    }
+}"
+`;
+
+exports[`t-slot directive template can just return a slot 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"__template__2\\"
+    let utils = this.constructor.utils;
+    let result;
+    let h = this.h;
+    const slot6 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
+    if (slot6) {
+        let children7= []
+        result = {}
+        slot6.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: children7, parent: extra.parent || context}));
+        utils.defineProxy(result, children7[0]);
+    }
+    return result;
+}"
+`;

tests/component/slots.test.ts

@@ -0,0 +1,883 @@
+import { Component, Env } from "../../src/component/component";
+import { QWeb } from "../../src/qweb/qweb";
+import { xml } from "../../src/tags";
+import { useState, useRef } from "../../src/hooks";
+import { makeTestFixture, makeTestEnv, nextTick } from "../helpers";
+
+//------------------------------------------------------------------------------
+// Setup and helpers
+//------------------------------------------------------------------------------
+
+// We create before each test:
+// - fixture: a div, appended to the DOM, intended to be the target of dom
+//   manipulations.  Note that it is removed after each test.
+// - env: a WEnv, necessary to create new components
+
+let fixture: HTMLElement;
+let env: Env;
+
+beforeEach(() => {
+  fixture = makeTestFixture();
+  env = makeTestEnv();
+  env.qweb.addTemplate("Component<any,any>", "<div></div>");
+  env.qweb.addTemplate(
+    "Counter",
+    `<div><t t-esc="state.counter"/><button t-on-click="inc">Inc</button></div>`
+  );
+  env.qweb.addTemplate("WidgetA", `<div>Hello<t t-component="b"/></div>`);
+  env.qweb.addTemplate("WidgetB", `<div>world</div>`);
+  Component.env = env;
+});
+
+afterEach(() => {
+  fixture.remove();
+});
+
+function children(w: Component<any, any>): Component<any, any>[] {
+  const childrenMap = w.__owl__.children;
+  return Object.keys(childrenMap).map(id => childrenMap[id]);
+}
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+describe("t-slot directive", () => {
+  test("can define and call slots", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Dialog>
+                  <t t-set="header"><span>header</span></t>
+                  <t t-set="footer"><span>footer</span></t>
+               </Dialog>
+            </div>
+            <div t-name="Dialog">
+              <div><t t-slot="header"/></div>
+              <div><t t-slot="footer"/></div>
+            </div>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(
+      "<div><div><div><span>header</span></div><div><span>footer</span></div></div></div>"
+    );
+    expect(env.qweb.templates.Parent.fn.toString()).toMatchSnapshot();
+    expect(env.qweb.templates.Dialog.fn.toString()).toMatchSnapshot();
+    expect(QWeb.slots["1_header"].toString()).toMatchSnapshot();
+    expect(QWeb.slots["1_footer"].toString()).toMatchSnapshot();
+  });
+
+  test("named slots can define a default content", async () => {
+    class Dialog extends Component<any, any> {
+      static template = xml`
+          <span>
+            <t t-slot="header">default content</t>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Dialog/></div>`;
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>default content</span></div>");
+    expect(env.qweb.templates[Dialog.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("dafault slots can define a default content", async () => {
+    class Dialog extends Component<any, any> {
+      static template = xml`
+          <span>
+            <t t-slot="default">default content</t>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Dialog/></div>`;
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>default content</span></div>");
+    expect(env.qweb.templates[Dialog.template].fn.toString()).toMatchSnapshot();
+  });
+
+  test("default content is not rendered if slot is provided", async () => {
+    class Dialog extends Component<any, any> {
+      static template = xml`
+          <span>
+            <t t-slot="default">default content</t>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Dialog>hey</Dialog></div>`;
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>hey</span></div>");
+  });
+
+  test("default content is not rendered if named slot is provided", async () => {
+    class Dialog extends Component<any, any> {
+      static template = xml`
+          <span>
+            <t t-slot="header">default content</t>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Dialog><t t-set="header">hey</t></Dialog></div>`;
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>hey</span></div>");
+  });
+
+  test("slots are rendered with proper context", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+              <span class="counter"><t t-esc="state.val"/></span>
+              <Dialog>
+                <t t-set="footer"><button t-on-click="doSomething">do something</button></t>
+              </Dialog>
+            </div>
+            <span t-name="Dialog"><t t-slot="footer"/></span>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+      state = useState({ val: 0 });
+      doSomething() {
+        this.state.val++;
+      }
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(
+      '<div><span class="counter">0</span><span><button>do something</button></span></div>'
+    );
+
+    fixture.querySelector("button")!.click();
+    await nextTick();
+
+    expect(fixture.innerHTML).toBe(
+      '<div><span class="counter">1</span><span><button>do something</button></span></div>'
+    );
+    expect(QWeb.slots["1_footer"].toString()).toMatchSnapshot();
+  });
+
+  test("slots are rendered with proper context, part 2", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+              <a t-name="Link" t-att-href="props.to">
+                  <t t-slot="default"/>
+              </a>
+              <div t-name="App">
+                  <u><li t-foreach="state.users" t-as="user" t-key="user.id">
+                      <Link to="'/user/' + user.id">User <t t-esc="user.name"/></Link>
+                  </li></u>
+              </div>
+          </templates>
+      `);
+    class Link extends Component<any, any> {}
+
+    class App extends Component<any, any> {
+      state = useState({
+        users: [
+          { id: 1, name: "Aaron" },
+          { id: 2, name: "David" }
+        ]
+      });
+      static components = { Link };
+    }
+
+    const app = new App();
+    await app.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(
+      '<div><u><li><a href="/user/1">User Aaron</a></li><li><a href="/user/2">User David</a></li></u></div>'
+    );
+    expect(env.qweb.templates.Link.fn.toString()).toMatchSnapshot();
+    expect(env.qweb.templates.App.fn.toString()).toMatchSnapshot();
+
+    // test updateprops here
+    app.state.users[1].name = "Mathieu";
+    await nextTick();
+    expect(fixture.innerHTML).toBe(
+      '<div><u><li><a href="/user/1">User Aaron</a></li><li><a href="/user/2">User Mathieu</a></li></u></div>'
+    );
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("slots are rendered with proper context, part 3", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+              <a t-name="Link" t-att-href="props.to">
+                  <t t-slot="default"/>
+              </a>
+              <div t-name="App">
+                  <u><li t-foreach="state.users" t-as="user" t-key="user.id" >
+                      <t t-set="userdescr" t-value="'User ' + user.name"/>
+                      <Link to="'/user/' + user.id"><t t-esc="userdescr"/></Link>
+                  </li></u>
+              </div>
+          </templates>
+      `);
+    class Link extends Component<any, any> {}
+
+    class App extends Component<any, any> {
+      state = useState({
+        users: [
+          { id: 1, name: "Aaron" },
+          { id: 2, name: "David" }
+        ]
+      });
+      static components = { Link };
+    }
+
+    const app = new App();
+    await app.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(
+      '<div><u><li><a href="/user/1">User Aaron</a></li><li><a href="/user/2">User David</a></li></u></div>'
+    );
+    expect(env.qweb.templates.Link.fn.toString()).toMatchSnapshot();
+    expect(env.qweb.templates.App.fn.toString()).toMatchSnapshot();
+
+    // test updateprops here
+    app.state.users[1].name = "Mathieu";
+    await nextTick();
+    expect(fixture.innerHTML).toBe(
+      '<div><u><li><a href="/user/1">User Aaron</a></li><li><a href="/user/2">User Mathieu</a></li></u></div>'
+    );
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("slots are rendered with proper context, part 4", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+              <a t-name="Link" t-att-href="props.to">
+                  <t t-slot="default"/>
+              </a>
+              <div t-name="App">
+                  <t t-set="userdescr" t-value="'User ' + state.user.name"/>
+                  <Link to="'/user/' + state.user.id"><t t-esc="userdescr"/></Link>
+              </div>
+          </templates>
+      `);
+    class Link extends Component<any, any> {}
+
+    class App extends Component<any, any> {
+      state = useState({ user: { id: 1, name: "Aaron" } });
+      static components = { Link };
+    }
+
+    const app = new App();
+    await app.mount(fixture);
+
+    expect(fixture.innerHTML).toBe('<div><a href="/user/1">User Aaron</a></div>');
+
+    expect(env.qweb.templates.App.fn.toString()).toMatchSnapshot();
+
+    // test updateprops here
+    app.state.user.name = "David";
+    await nextTick();
+    expect(fixture.innerHTML).toBe('<div><a href="/user/1">User David</a></div>');
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("refs are properly bound in slots", async () => {
+    class Dialog extends Component<any, any> {
+      static template = xml`<span><t t-slot="footer"/></span>`;
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`
+            <div>
+              <span class="counter"><t t-esc="state.val"/></span>
+              <Dialog>
+                <t t-set="footer"><button t-ref="myButton" t-on-click="doSomething">do something</button></t>
+              </Dialog>
+            </div>
+          `;
+      static components = { Dialog };
+      state = useState({ val: 0 });
+      button = useRef("myButton");
+      doSomething() {
+        this.state.val++;
+      }
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(
+      '<div><span class="counter">0</span><span><button>do something</button></span></div>'
+    );
+
+    parent.button.el!.click();
+    await nextTick();
+
+    expect(fixture.innerHTML).toBe(
+      '<div><span class="counter">1</span><span><button>do something</button></span></div>'
+    );
+    expect(QWeb.slots["1_footer"].toString()).toMatchSnapshot();
+  });
+
+  test("content is the default slot", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Dialog>
+                  <span>sts rocks</span>
+               </Dialog>
+            </div>
+            <div t-name="Dialog"><t t-slot="default"/></div>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><div><span>sts rocks</span></div></div>");
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("default slot work with text nodes", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Dialog>sts rocks</Dialog>
+            </div>
+            <div t-name="Dialog"><t t-slot="default"/></div>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><div>sts rocks</div></div>");
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("multiple roots are allowed in a named slot", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Dialog>
+                  <t t-set="content">
+                      <span>sts</span>
+                      <span>rocks</span>
+                  </t>
+               </Dialog>
+            </div>
+            <div t-name="Dialog"><t t-slot="content"/></div>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><div><span>sts</span><span>rocks</span></div></div>");
+    expect(QWeb.slots["1_content"].toString()).toMatchSnapshot();
+  });
+
+  test("multiple roots are allowed in a default slot", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Dialog>
+                  <span>sts</span>
+                  <span>rocks</span>
+               </Dialog>
+            </div>
+            <div t-name="Dialog"><t t-slot="default"/></div>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><div><span>sts</span><span>rocks</span></div></div>");
+    expect(QWeb.slots["1_default"].toString()).toMatchSnapshot();
+  });
+
+  test("missing slots are ignored", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+              <Dialog/>
+            </div>
+            <span t-name="Dialog">
+              <t t-slot="default"/>
+              <span>some content</span>
+              <t t-slot="footer"/>
+            </span>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span><span>some content</span></span></div>");
+  });
+
+  test("t-debug on a t-set (defining a slot)", async () => {
+    const consoleLog = console.log;
+    console.log = jest.fn();
+
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+              <Dialog><t t-set="content" t-debug="">abc</t></Dialog>
+            </div>
+            <span t-name="Dialog">
+              <t t-slot="content"/>
+            </span>
+          </templates>
+      `);
+    class Dialog extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Dialog };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+    expect(console.log).toHaveBeenCalledTimes(0);
+    console.log = consoleLog;
+  });
+
+  test("slot preserves properly parented relationship", async () => {
+    env.qweb.addTemplates(`
+          <templates>
+            <div t-name="Parent">
+               <Child>
+                  <GrandChild/>
+               </Child>
+            </div>
+            <div t-name="Child"><t t-slot="default"/></div>
+            <div t-name="GrandChild">Grand Child</div>
+          </templates>
+      `);
+    class Child extends Component<any, any> {}
+    class GrandChild extends Component<any, any> {}
+    class Parent extends Component<any, any> {
+      static components = { Child, GrandChild };
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><div><div>Grand Child</div></div></div>");
+
+    const parentChildren = children(parent);
+    expect(parentChildren.length).toBe(1);
+    expect(parentChildren[0]).toBeInstanceOf(Child);
+
+    const childrenChildren = children(parentChildren[0]);
+    expect(childrenChildren.length).toBe(1);
+    expect(childrenChildren[0]).toBeInstanceOf(GrandChild);
+  });
+
+  test("nested slots: evaluation context and parented relationship", async () => {
+    let slot;
+    class Slot extends Component<any, any> {
+      static template = xml`<span t-esc="props.val"/>`;
+      constructor(parent, props) {
+        super(parent, props);
+        slot = this;
+      }
+    }
+    class GrandChild extends Component<any, any> {
+      static template = xml`<div><t t-slot="default"/></div>`;
+    }
+    class Child extends Component<any, any> {
+      static components = { GrandChild };
+      static template = xml`
+          <GrandChild>
+            <t t-slot="default"/>
+          </GrandChild>`;
+    }
+    class Parent extends Component<any, any> {
+      static components = { Child, Slot };
+      static template = xml`<Child><Slot val="state.val"/></Child>`;
+      state = useState({ val: 3 });
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>3</span></div>");
+    expect(slot.__owl__.parent).toBeInstanceOf(GrandChild);
+  });
+
+  test("slot are properly rendered if inner props are changed", async () => {
+    env.qweb.addTemplates(`
+      <templates>
+          <div t-name="SomeComponent">
+              SC:<t t-esc="props.val"/>
+          </div>
+  
+  
+          <div t-name="GenericComponent">
+              <t t-slot="default" />
+          </div>
+  
+          <div t-name="App">
+              <button t-on-click="inc">Inc[<t t-esc="state.val"/>]</button>
+              <GenericComponent>
+                  <SomeComponent val="state.val"/>
+              </GenericComponent>
+          </div>
+      </templates>
+      `);
+    class SomeComponent extends Component<any, any> {}
+    class GenericComponent extends Component<any, any> {}
+    class App extends Component<any, any> {
+      static components = { GenericComponent, SomeComponent };
+      state = useState({ val: 4 });
+
+      inc() {
+        this.state.val++;
+      }
+    }
+    const app = new App();
+    await app.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><button>Inc[4]</button><div><div> SC:4</div></div></div>");
+    (<any>fixture.querySelector("button")).click();
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><button>Inc[5]</button><div><div> SC:5</div></div></div>");
+  });
+
+  test("slots and wrapper components", async () => {
+    class Link extends Component<any, any> {
+      static template = xml`
+          <a href="abc">
+              <t t-slot="default"/>
+          </a>`;
+    }
+
+    class A extends Component<any, any> {
+      static template = xml`<Link>hey</Link>`;
+      static components = { Link: Link };
+    }
+
+    const a = new A();
+    await a.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(`<a href="abc">hey</a>`);
+  });
+
+  test("template can just return a slot", async () => {
+    class Child extends Component<any, any> {
+      static template = xml`<span><t t-esc="props.value"/></span>`;
+    }
+    class SlotComponent extends Component<any, any> {
+      static template = xml`<t t-slot="default"/>`;
+    }
+
+    class Parent extends Component<any, any> {
+      static template = xml`
+          <div>
+              <SlotComponent><Child value="state.value"/></SlotComponent>
+          </div>`;
+      static components = { SlotComponent, Child };
+      state = useState({ value: 3 });
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><span>3</span></div>");
+
+    expect(QWeb.TEMPLATES[SlotComponent.template].fn.toString()).toMatchSnapshot();
+
+    parent.state.value = 5;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><span>5</span></div>");
+  });
+
+  test("multiple slots containing components", async () => {
+    class C extends Component<any, any> {
+      static template = xml`<span><t t-esc="props.val"/></span>`;
+    }
+    class B extends Component<any, any> {
+      static template = xml`<div><t t-slot="s1"/><t t-slot="s2"/></div>`;
+    }
+    class A extends Component<any, any> {
+      static template = xml`
+          <B>
+            <t t-set="s1"><C val="1"/></t>
+            <t t-set="s2"><C val="2"/></t>
+          </B>`;
+      static components = { B, C };
+    }
+
+    const a = new A();
+    await a.mount(fixture);
+
+    expect(fixture.innerHTML).toBe(`<div><span>1</span><span>2</span></div>`);
+  });
+
+  test("slots in t-foreach and re-rendering", async () => {
+    class Child extends Component<any, any> {
+      static template = xml`<span><t t-esc="state.val"/><t t-slot="default"/></span>`;
+      state = useState({ val: "A" });
+      mounted() {
+        this.state.val = "B";
+      }
+    }
+    class Parent extends Component<any, any> {
+      static components = { Child };
+      static template = xml`
+          <div>
+            <t t-foreach="Array(2)" t-as="n" t-key="n_index">
+              <Child><t t-esc="n_index"/></Child>
+            </t>
+          </div>`;
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><span>A0</span><span>A1</span></div>");
+
+    await nextTick(); // wait for the changes triggered in mounted to be applied
+    expect(fixture.innerHTML).toBe("<div><span>B0</span><span>B1</span></div>");
+  });
+
+  test("slots in t-foreach with t-set and re-rendering", async () => {
+    class Child extends Component<any, any> {
+      static template = xml`
+          <span>
+            <t t-esc="state.val"/>
+            <t t-slot="default"/>
+          </span>`;
+      state = useState({ val: "A" });
+      mounted() {
+        this.state.val = "B";
+      }
+    }
+    class ParentWidget extends Component<any, any> {
+      static components = { Child };
+      static template = xml`
+          <div>
+            <t t-foreach="Array(2)" t-as="n" t-key="n_index">
+              <t t-set="dummy" t-value="n_index"/>
+              <Child><t t-esc="dummy"/></Child>
+            </t>
+          </div>`;
+    }
+
+    const widget = new ParentWidget();
+    await widget.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><span>A0</span><span>A1</span></div>");
+
+    await nextTick(); // wait for changes triggered in mounted to be applied
+    expect(fixture.innerHTML).toBe("<div><span>B0</span><span>B1</span></div>");
+  });
+
+  test("nested slots in same template", async () => {
+    let child, child2, child3;
+    class Child extends Component<any, any> {
+      static template = xml`
+          <span id="c1">
+            <div>
+              <t t-slot="default"/>
+            </div>
+          </span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        child = this;
+      }
+    }
+    class Child2 extends Component<any, any> {
+      static template = xml`
+          <span id="c2">
+            <t t-slot="default"/>
+          </span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        child2 = this;
+      }
+    }
+    class Child3 extends Component<any, any> {
+      static template = xml`
+          <span>Child 3</span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        child3 = this;
+      }
+    }
+    class Parent extends Component<any, any> {
+      static components = { Child, Child2, Child3 };
+      static template = xml`
+          <span id="parent">
+            <Child>
+              <Child2>
+                <Child3/>
+              </Child2>
+            </Child>
+          </span>`;
+    }
+
+    const widget = new Parent();
+    await widget.mount(fixture);
+    expect(fixture.innerHTML).toBe(
+      '<span id="parent"><span id="c1"><div><span id="c2"><span>Child 3</span></span></div></span></span>'
+    );
+
+    expect(child3.__owl__.parent).toStrictEqual(child2);
+    expect(child2.__owl__.parent).toStrictEqual(child);
+    expect(child.__owl__.parent).toStrictEqual(widget);
+  });
+
+  test("t-slot nested within another slot", async () => {
+    let portal, modal, child3;
+    class Child3 extends Component<any, any> {
+      static template = xml`
+          <span>Child 3</span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        child3 = this;
+      }
+    }
+    class Modal extends Component<any, any> {
+      static template = xml`
+          <span id="modal">
+            <t t-slot="default"/>
+          </span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        modal = this;
+      }
+    }
+    class Portal extends Component<any, any> {
+      static template = xml`
+          <span id="portal">
+            <t t-slot="default"/>
+          </span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        portal = this;
+      }
+    }
+    class Dialog extends Component<any, any> {
+      static components = { Modal, Portal };
+      static template = xml`
+          <span id="c2">
+            <Modal>
+              <Portal>
+                <t t-slot="default"/>
+              </Portal>
+             </Modal>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static components = { Child3, Dialog };
+      static template = xml`
+          <span id="c1">
+            <Dialog>
+              <Child3/>
+            </Dialog>
+          </span>`;
+    }
+
+    const widget = new Parent();
+    await widget.mount(fixture);
+    expect(fixture.innerHTML).toBe(
+      '<span id="c1"><span id="c2"><span id="modal"><span id="portal"><span>Child 3</span></span></span></span></span>'
+    );
+
+    expect(child3.__owl__.parent).toStrictEqual(portal);
+    expect(portal.__owl__.parent).toStrictEqual(modal);
+  });
+
+  test("t-slot supports many instances", async () => {
+    let child3;
+    class Child3 extends Component<any, any> {
+      static template = xml`
+          <span>Child 3</span>`;
+      constructor(parent, props) {
+        super(parent, props);
+        child3 = this;
+      }
+    }
+    class Dialog extends Component<any, any> {
+      static template = xml`
+          <span id="c2">
+            <t t-slot="default"/>
+          </span>`;
+    }
+    class Parent extends Component<any, any> {
+      static components = { Child3, Dialog };
+      static template = xml`
+          <span id="c1">
+            <Dialog>
+              <Child3 val="state.lol"/>
+            </Dialog>
+          </span>`;
+      state = { lol: "k" };
+    }
+
+    const widget = new Parent();
+    await widget.mount(fixture);
+    expect(child3.props.val).toBe("k");
+
+    const widget_1 = new Parent();
+    widget_1.state.lol = "m";
+    await widget_1.mount(fixture);
+    expect(child3.props.val).toBe("m");
+  });
+
+  test("slots in slots, with vars", async () => {
+    class B extends Component<any, any> {
+      static template = xml`<span><t t-slot="default"/></span>`;
+    }
+    class A extends Component<any, any> {
+      static template = xml`
+          <div>
+            <B>
+              <t t-slot="default"/>
+            </B>
+          </div>`;
+      static components = { B };
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`
+          <div>
+            <t t-set="test" t-value="state.name"/>
+            <A>
+              <p>hey<t t-esc="test"/></p>
+            </A>
+          </div>`;
+      static components = { A };
+      state = { name: "aaron" };
+    }
+
+    const parent = new Parent();
+    await parent.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><div><span><p>heyaaron</p></span></div></div>");
+  });
+});

tests/helpers.ts

@@ -1,4 +1,4 @@
-import { Env } from "../src/component/component";
+import { Env, Component } from "../src/component/component";
 import { scheduler } from "../src/component/scheduler";
 import { EvalContext, QWeb } from "../src/qweb/qweb";
 import { CompilationContext } from "../src/qweb/compilation_context";
@@ -25,6 +25,7 @@ beforeEach(() => {
   slots = Object.assign({}, QWeb.slots);
   nextId = QWeb.nextId;
   TEMPLATES = Object.assign({}, QWeb.TEMPLATES);
+  Component.scheduler.tasks = [];
 });
 
 afterEach(() => {
@@ -32,6 +33,7 @@ afterEach(() => {
   QWeb.slots = slots;
   QWeb.nextId = nextId;
   QWeb.TEMPLATES = TEMPLATES;
+  Component.scheduler.tasks = [];
 });
 
 // helpers
@@ -121,11 +123,8 @@ export function renderToString(
   context: EvalContext = {},
   extra?: any
 ): string {
-  const node = renderToDOM(qweb, t, context, extra);
-  const result = node instanceof Text ? node.textContent! : node.outerHTML;
-  if (result !== qweb.renderToString(t, context, extra)) {
-    throw new Error("HTML string returned by renderToString helper does not match QWeb render");
-  }
+  const result = qweb.renderToString(t, context, extra);
+  expect(qweb.templates[t].fn.toString()).toMatchSnapshot();
   return result;
 }
 

tests/qweb/qweb.test.ts

@@ -120,9 +120,11 @@ describe("t-esc", () => {
     expect(renderToString(qweb, "test", { var: "ok" })).toBe("<span>ok</span>");
   });
 
-  test.skip("escaping", () => {
+  test("escaping", () => {
     qweb.addTemplate("test", `<span><t t-esc="var"/></span>`);
-    expect(renderToString(qweb, "test", { var: "<ok>" })).toBe("<span>&lt;ok&gt;</span>");
+    expect(renderToString(qweb, "test", { var: "<ok>abc</ok>" })).toBe(
+      "<span>&amp;lt;ok&amp;gt;abc&amp;lt;/ok&amp;gt;</span>"
+    );
   });
 
   test("escaping on a node", () => {
@@ -139,17 +141,49 @@ describe("t-esc", () => {
     qweb.addTemplate("test", `<span t-esc="var">nope</span>`);
     expect(renderToString(qweb, "test")).toBe("<span>nope</span>");
   });
+
   test("t-esc is escaped", () => {
     qweb.addTemplate("test", `<div><t t-set="var"><p>escaped</p></t><t t-esc="var"/></div>`);
     const domRendered = renderToDOM(qweb, "test");
     expect(domRendered.textContent).toBe("<p>escaped</p>");
   });
+
   test("t-esc=0 is escaped", () => {
     qweb.addTemplate("test", `<span><t t-esc="0"/></span>`);
     qweb.addTemplate("testCaller", `<div><t t-call="test"><p>escaped</p></t></div>`);
     const domRendered = renderToDOM(qweb, "testCaller") as HTMLElement;
     expect(domRendered.querySelector("span")!.textContent).toBe("<p>escaped</p>");
   });
+
+  test("div with falsy values", () => {
+    qweb.addTemplate(
+      "test",
+      `
+      <div>
+        <p t-esc="v1"/>
+        <p t-esc="v2"/>
+        <p t-esc="v3"/>
+        <p t-esc="v4"/>
+        <p t-esc="v5"/>
+      </div>`
+    );
+    const vals = {
+      v1: false,
+      v2: undefined,
+      v3: null,
+      v4: 0,
+      v5: ""
+    };
+    expect(renderToString(qweb, "test", vals)).toBe(
+      "<div><p>false</p><p></p><p></p><p>0</p><p></p></div>"
+    );
+  });
+
+  test("t-esc work with spread operator", () => {
+    qweb.addTemplate("test", `<span><t t-esc="[...state.list]"/></span>`);
+    const result = renderToString(qweb, "test", { state: { list: [1, 2] } });
+    expect(result).toBe("<span>1,2</span>");
+  });
 });
 
 describe("t-raw", () => {
@@ -256,6 +290,18 @@ describe("t-set", () => {
     );
   });
 
+  test("t-set with content and sub t-esc", () => {
+    qweb.addTemplate(
+      "test",
+      `<div>
+        <t t-set="setvar"><t t-esc="beep"/> boop</t>
+        <t t-esc="setvar"/>
+      </div>`
+    );
+
+    expect(renderToString(qweb, "test", { beep: "beep" })).toBe("<div>beep boop</div>");
+  });
+
   test("evaluate value expression, part 2", () => {
     qweb.addTemplate(
       "test",
@@ -318,12 +364,13 @@ describe("t-set", () => {
         <t t-set="v1" t-value="'after'"/>
         <t t-set="v3" t-value="true"/>
         <t t-raw="v2"/>
-      </div>`);
+      </div>`
+    );
 
-      expect(renderToString(qweb, "test")).toBe("<div><span>before</span></div>");
-    });
+    expect(renderToString(qweb, "test")).toBe("<div><span>before</span></div>");
+  });
 
-    test("t-set with t-value (truthy) and body", () => {
+  test("t-set with t-value (truthy) and body", () => {
     qweb.addTemplate(
       "test",
       `<div>
@@ -335,10 +382,11 @@ describe("t-set", () => {
         <t t-set="v1" t-value="'after'"/>
         <t t-set="v3" t-value="false"/>
         <t t-raw="v2"/>
-      </div>`);
+      </div>`
+    );
 
-      expect(renderToString(qweb, "test")).toBe("<div>Truthy</div>");
-    });
+    expect(renderToString(qweb, "test")).toBe("<div>Truthy</div>");
+  });
 });
 
 describe("t-if", () => {
@@ -426,7 +474,7 @@ describe("t-if", () => {
   });
 
   test("t-esc with t-elif", () => {
-    qweb.addTemplate("test", `<div><t t-if="false">abc</t><t t-else="1" t-esc="'x'"/></div>`);
+    qweb.addTemplate("test", `<div><t t-if="false">abc</t><t t-else="" t-esc="'x'"/></div>`);
     expect(renderToString(qweb, "test")).toBe("<div>x</div>");
   });
 
@@ -618,7 +666,7 @@ describe("attributes", () => {
     expect(result).toBe(`<div foo="a 0 is 1 of 2 ]"></div>`);
   });
 
-  test.skip("various escapes", () => {
+  test("various escapes", () => {
     // not needed??
     qweb.addTemplate(
       "test",
@@ -634,7 +682,7 @@ describe("attributes", () => {
       baz: 1,
       qux: { qux: "<>" }
     });
-    const expected = `<div foo="&lt;foo" bar="&lt;bar&gt;" baz="&lt;&quot;&lt;baz&gt;&quot;&gt;" qux="&lt;&gt;"></div>`;
+    const expected = '<div foo="<foo" bar="0" baz="<1>" qux="<>"></div>';
     expect(result).toBe(expected);
   });
 
@@ -880,6 +928,23 @@ describe("t-call (template calling", () => {
     expect(trim(renderToString(qweb, "abcd"))).toBe(expected);
   });
 
+  test("t-call, conditional and t-set in t-call body", () => {
+    QWeb.registerTemplate("callee1", "<div>callee1</div>");
+    QWeb.registerTemplate("callee2", '<div>callee2 <t t-esc="v"/></div>');
+    QWeb.registerTemplate(
+      "caller",
+      `<div>
+        <t t-set="v1" t-value="'elif'"/>
+        <t t-if="v1 === 'if'" t-call="callee1" />
+        <t t-elif="v1 === 'elif'" t-call="callee2" >
+          <t t-set="v" t-value="'success'" />
+        </t>
+       </div>`
+    );
+    const rendered = renderToString(qweb, "caller");
+    expect(rendered).toBe(`<div><div>callee2 success</div></div>`);
+  });
+
   test("t-call with t-set inside and outside", () => {
     qweb.addTemplates(`
       <templates>
@@ -1272,6 +1337,69 @@ describe("t-on", () => {
     expect(owner.state.counter).toBe(2);
   });
 
+  test("t-on with inline statement, part 2", () => {
+    qweb.addTemplate("test", `<button t-on-click="state.flag = !state.flag">Toggle</button>`);
+    let owner = {
+      state: {
+        flag: true
+      }
+    };
+    const node = renderToDOM(qweb, "test", owner, { handlers: [] });
+    expect(owner.state.flag).toBe(true);
+    (<HTMLElement>node).click();
+    expect(owner.state.flag).toBe(false);
+    (<HTMLElement>node).click();
+    expect(owner.state.flag).toBe(true);
+  });
+
+  test("t-on with inline statement, part 3", () => {
+    qweb.addTemplate("test", `<button t-on-click="state.n = someFunction(3)">Toggle</button>`);
+    let owner = {
+      someFunction(n) {
+        return n + 1;
+      },
+      state: {
+        n: 11
+      }
+    };
+    const node = renderToDOM(qweb, "test", owner, { handlers: [] });
+    expect(owner.state.n).toBe(11);
+    (<HTMLElement>node).click();
+    expect(owner.state.n).toBe(4);
+  });
+
+  test("t-on with t-call", async () => {
+    expect.assertions(2);
+    qweb.addTemplate("sub", `<p t-on-click="update">lucas</p>`);
+    qweb.addTemplate("main", `<div><t t-call="sub"/></div>`);
+
+    let owner = {
+      update() {
+        expect(this).toBe(owner);
+      }
+    };
+
+    const node = renderToDOM(qweb, "main", owner, { handlers: [] });
+    (<HTMLElement>node).querySelector("p")!.click();
+  });
+
+  test("t-on, with arguments and t-call", async () => {
+    expect.assertions(3);
+    qweb.addTemplate("sub", `<p t-on-click="update(value)">lucas</p>`);
+    qweb.addTemplate("main", `<div><t t-call="sub"/></div>`);
+
+    let owner = {
+      update(val) {
+        expect(this).toBe(owner);
+        expect(val).toBe(444);
+      },
+      value: 444
+    };
+
+    const node = renderToDOM(qweb, "main", owner, { handlers: [] });
+    (<HTMLElement>node).querySelector("p")!.click();
+  });
+
   test("t-on with prevent and/or stop modifiers", async () => {
     expect.assertions(7);
     qweb.addTemplate(
@@ -1644,7 +1772,7 @@ describe("debugging", () => {
     console.log = jest.fn();
     qweb.addTemplate(
       "test",
-      `<div t-debug="1"><t t-if="true"><span t-debug="1">hey</span></t></div>`
+      `<div t-debug=""><t t-if="true"><span t-debug="">hey</span></t></div>`
     );
     qweb.render("test");
     expect(qweb.templates.test.fn.toString()).toMatchSnapshot();
@@ -1658,7 +1786,7 @@ describe("debugging", () => {
     console.log = jest.fn();
     qweb.addTemplates(`
       <templates>
-      <p t-name="sub" t-debug="1">coucou</p>
+      <p t-name="sub" t-debug="">coucou</p>
       <div t-name="test">
         <t t-call="sub"/>
       </div>

tests/qweb/qweb_expressions.test.ts

@@ -50,6 +50,12 @@ describe("tokenizer", () => {
       { type: "OPERATOR", value: "typeof " },
       { type: "SYMBOL", value: "a" }
     ]);
+
+    expect(tokenize("a...1")).toEqual([
+      { type: "SYMBOL", value: "a" },
+      { type: "OPERATOR", value: "..." },
+      { type: "VALUE", value: "1" }
+    ]);
   });
 
   test("strings", () => {
@@ -170,4 +176,17 @@ describe("expression evaluation", () => {
       "scope['list'].map((elem,index)=>elem+index)"
     );
   });
+
+  test("assignation", () => {
+    expect(compileExpr("a = b", {})).toBe("scope['a']=scope['b']");
+    expect(compileExpr("a += b", {})).toBe("scope['a']+=scope['b']");
+    expect(compileExpr("a -= b", {})).toBe("scope['a']-=scope['b']");
+    expect(compileExpr("a.b = !a.b", {})).toBe("scope['a'].b=!scope['a'].b");
+  });
+
+  test("spread operator", () => {
+    expect(compileExpr("[...state.list]", {})).toBe("[...scope['state'].list]");
+    expect(compileExpr("f(...state.list)", {})).toBe("scope['f'](...scope['state'].list)");
+    expect(compileExpr("f([...list])", {})).toBe("scope['f']([...scope['list']])");
+  });
 });

tests/router/__snapshots__/link.test.ts.snap

@@ -6,17 +6,17 @@ exports[`Link component can render simple cases 1`] = `
     // Template name: \\"__template__1\\"
     let utils = this.constructor.utils;
     let scope = Object.create(context);
-    var h = this.h;
-    let _5 = utils.toObj({'router-link-active':scope['isActive']});
-    var _6 = scope['href'];
-    let c7 = [], p7 = {key:7,attrs:{href: _6},class:_5,on:{}};
-    var vn7 = h('a', p7, c7);
-    extra.handlers['click' + 7] = extra.handlers['click' + 7] || function (e) {if (!context.__owl__.isMounted){return}const fn = context['navigate'];if (fn) { fn.call(context, e); } else { context.navigate; }};
-    p7.on['click'] = extra.handlers['click' + 7];
+    let h = this.h;
+    let _4 = utils.toObj({'router-link-active':scope['isActive']});
+    let _5 = scope['href'];
+    let c6 = [], p6 = {key:6,attrs:{href: _5},class:_4,on:{}};
+    let vn6 = h('a', p6, c6);
+    extra.handlers['click__7__'] = extra.handlers['click__7__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['navigate'](e);};
+    p6.on['click'] = extra.handlers['click__7__'];
     const slot8 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
     if (slot8) {
-        slot8.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c7, parent: extra.parent || context}));
+        slot8.call(this, context.__owl__.scope, Object.assign({}, extra, {parentNode: c6, parent: extra.parent || context}));
     }
-    return vn7;
+    return vn6;
 }"
 `;

tests/router/__snapshots__/route_component.test.ts.snap

@@ -9,35 +9,37 @@ exports[`RouteComponent can render simple cases 1`] = `
     let parent = context;
     let scope = Object.create(context);
     let result;
-    var h = this.h;
+    let h = this.h;
     if (scope['routeComponent']) {
-        const nodeKey5 = scope['env'].router.currentRouteName;
-        //COMPONENT
-        let k7 = \`__8__\` + nodeKey5;
-        let w6 = k7 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k7]] : false;
-        let vn9 = {};
-        result = vn9;
-        let props6 = Object.assign({}, scope['env'].router.currentParams);
-        if (w6 && w6.__owl__.currentFiber && !w6.__owl__.vnode) {
-            w6.destroy();
-            w6 = false;
+        {
+            let key0 = scope['env'].router.currentRouteName;
+            // Component 'routeComponent'
+            let k5 = \`__5__\${key0}__\`;
+            let w4 = k5 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k5]] : false;
+            let vn6 = {};
+            result = vn6;
+            let props4 = Object.assign({}, scope['env'].router.currentParams);
+            if (w4 && w4.__owl__.currentFiber && !w4.__owl__.vnode) {
+                w4.destroy();
+                w4 = false;
+            }
+            if (w4) {
+                w4.__updateProps(props4, extra.fiber, undefined);
+                let pvnode = w4.__owl__.pvnode;
+                utils.defineProxy(vn6, pvnode);
+            } else {
+                let componentKey4 = \`routeComponent\`;
+                let W4 = context.constructor.components[componentKey4] || QWeb.components[componentKey4]|| scope['routeComponent'];
+                if (!W4) {throw new Error('Cannot find the definition of component \\"' + componentKey4 + '\\"')}
+                w4 = new W4(parent, props4);
+                parent.__owl__.cmap[k5] = w4.__owl__.id;
+                let fiber = w4.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+                let pvnode = h('dummy', {key: k5, hook: {remove() {},destroy(vn) {w4.destroy();}}});
+                utils.defineProxy(vn6, pvnode);
+                w4.__owl__.pvnode = pvnode;
+            }
+            w4.__owl__.parentLastFiberId = extra.fiber.id;
         }
-        if (w6) {
-            w6.__updateProps(props6, extra.fiber, undefined);
-            let pvnode = w6.__owl__.pvnode;
-            utils.defineProxy(vn9, pvnode);
-        } else {
-            let componentKey6 = \`routeComponent\`;
-            let W6 = context.constructor.components[componentKey6] || QWeb.components[componentKey6]|| scope['routeComponent'];
-            if (!W6) {throw new Error('Cannot find the definition of component \\"' + componentKey6 + '\\"')}
-            w6 = new W6(parent, props6);
-            parent.__owl__.cmap[k7] = w6.__owl__.id;
-            let fiber = w6.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-            let pvnode = h('dummy', {key: k7, hook: {remove() {},destroy(vn) {w6.destroy();}}});
-            utils.defineProxy(vn9, pvnode);
-            w6.__owl__.pvnode = pvnode;
-        }
-        w6.__owl__.parentLastFiberId = extra.fiber.id;
     }
     return result;
 }"

tests/store_hooks.test.ts

@@ -84,6 +84,38 @@ describe("connecting a component to store", () => {
     expect(fixture.innerHTML).toBe("<div><span>ok</span></div>");
   });
 
+  test("map works on the result of useStore when the resulting array changes for a bigger one", async () => {
+    const state = { smallerArray: [1], biggerArray: [2, 3], useSmallArray: true };
+    const store = new Store({ state });
+
+    class App extends Component<any, any> {
+      static template = xml`<div t-esc="mapAdd"/>`;
+      storeProps = {
+        array: useStore(state => {
+          if (state.useSmallArray) {
+            return state.smallerArray;
+          }
+          return state.biggerArray;
+        })
+      };
+      get mapAdd() {
+        return this.storeProps.array.map(a => {
+          return a + 1;
+        });
+      }
+    }
+
+    (<any>env).store = store;
+    const app = new App();
+
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div>2</div>");
+
+    store.state.useSmallArray = false;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div>3,4</div>");
+  });
+
   test("throw error if no store is found", async () => {
     class App extends Component<any, any> {
       static template = xml`<div></div>`;

tools/playground/samples.js

@@ -1101,7 +1101,7 @@ const RESPONSIVE_XML = `<templates>
         <t t-raw="maincontent"/>
       </div>
     </div>
-    <t t-else="1">
+    <t t-else="">
       <t t-raw="maincontent"/>
     </t>
   </div>
@@ -1438,7 +1438,7 @@ const FORM_XML = `<templates>
     <div>Text: <t t-esc="state.text"/></div>
     <div>Other Text: <t t-esc="state.othertext"/></div>
     <div>Number: <t t-esc="state.number"/></div>
-    <div>Boolean: <t t-if="state.bool">True</t><t t-else="1">False</t></div>
+    <div>Boolean: <t t-if="state.bool">True</t><t t-else="">False</t></div>
     <div>Color: <t t-esc="state.color"/></div>
   </div>
 </templates>