fix crash in template compilation with objects in props

fix #1

src/qweb.ts

@@ -512,9 +512,28 @@ export class QWeb {
   }
 
   _formatExpression(e: string, ctx?: Context): string {
+    e = e.trim();
     if (e in this.exprCache) {
       return this.exprCache[e];
     }
+    if (e[0] === "{" && e[e.length - 1] === "}") {
+      const innerExpr = e
+        .slice(1, -1)
+        .split(",")
+        .map(p => {
+          let [key, val] = p.trim().split(":");
+          if (key === "") {
+            return "";
+          }
+          if (!val) {
+            val = key;
+          }
+          return `${key}: ${this._formatExpression(val, ctx)}`;
+        })
+        .join(",");
+      return "{" + innerExpr + "}";
+    }
+
     // Thanks CHM for this code...
     const chars = e.split("");
     let instring = "";
@@ -840,23 +859,7 @@ const widgetDirective: Directive = {
       }
     }
     if (props) {
-      props = props.trim();
-      if (props[0] === "{" && props[props.length - 1] === "}") {
-        const innerProp = props
-          .slice(1, -1)
-          .split(",")
-          .map(p => {
-            let [key, val] = p.split(":");
-            if (!val) {
-              val = key;
-            }
-            return `${key}: ${qweb._formatExpression(val, ctx)}`;
-          })
-          .join(",");
-        props = "{" + innerProp + "}";
-      } else {
-        props = qweb._formatExpression(props);
-      }
+      props = qweb._formatExpression(props, ctx);
     }
     let dummyID = ctx.generateID();
     let defID = ctx.generateID();

tests/__snapshots__/qweb.test.ts.snap

@@ -988,6 +988,32 @@ exports[`t-on can bind handlers with arguments 1`] = `
 }"
 `;
 
+exports[`t-on can bind handlers with empty object (with non empty inner string 1`] = `
+"function anonymous(context,extra
+) {
+    let owner = context;
+    let h = this.utils.h;
+    let c1 = [], p1 = {key:1,on:{}};
+    let vn1 = h('button', p1, c1);
+    p1.on['click'] = context['doSomething'].bind(owner, {});
+    c1.push({text: \`Click\`});
+    return vn1;
+}"
+`;
+
+exports[`t-on can bind handlers with empty object 1`] = `
+"function anonymous(context,extra
+) {
+    let owner = context;
+    let h = this.utils.h;
+    let c1 = [], p1 = {key:1,on:{}};
+    let vn1 = h('button', p1, c1);
+    p1.on['click'] = context['doSomething'].bind(owner, {});
+    c1.push({text: \`Click\`});
+    return vn1;
+}"
+`;
+
 exports[`t-on can bind handlers with loop variable as argument 1`] = `
 "function anonymous(context,extra
 ) {
@@ -1025,6 +1051,19 @@ exports[`t-on can bind handlers with loop variable as argument 1`] = `
 }"
 `;
 
+exports[`t-on can bind handlers with object arguments 1`] = `
+"function anonymous(context,extra
+) {
+    let owner = context;
+    let h = this.utils.h;
+    let c1 = [], p1 = {key:1,on:{}};
+    let vn1 = h('button', p1, c1);
+    p1.on['click'] = context['add'].bind(owner, {val: 5});
+    c1.push({text: \`Click\`});
+    return vn1;
+}"
+`;
+
 exports[`t-on can bind two event handlers 1`] = `
 "function anonymous(context,extra
 ) {

tests/qweb.test.ts

@@ -763,6 +763,64 @@ describe("t-on", () => {
     expect(a).toBe(6);
   });
 
+  test("can bind handlers with object arguments", () => {
+    qweb.addTemplate(
+      "test",
+      `<button t-on-click="add({val: 5})">Click</button>`
+    );
+    let a = 1;
+    const node = renderToDOM(
+      qweb,
+      "test",
+      {
+        add({ val }) {
+          a = a + val;
+        }
+      },
+      { handlers: [] }
+    );
+    (<HTMLElement>node).click();
+    expect(a).toBe(6);
+  });
+
+  test("can bind handlers with empty object", () => {
+    expect.assertions(2);
+    qweb.addTemplate(
+      "test",
+      `<button t-on-click="doSomething({})">Click</button>`
+    );
+    const node = renderToDOM(
+      qweb,
+      "test",
+      {
+        doSomething(arg) {
+          expect(arg).toEqual({});
+        }
+      },
+      { handlers: [] }
+    );
+    (<HTMLElement>node).click();
+  });
+
+  test("can bind handlers with empty object (with non empty inner string", () => {
+    expect.assertions(2);
+    qweb.addTemplate(
+      "test",
+      `<button t-on-click="doSomething({ })">Click</button>`
+    );
+    const node = renderToDOM(
+      qweb,
+      "test",
+      {
+        doSomething(arg) {
+          expect(arg).toEqual({});
+        }
+      },
+      { handlers: [] }
+    );
+    (<HTMLElement>node).click();
+  });
+
   test("can bind handlers with loop variable as argument", () => {
     expect.assertions(2);
     qweb.addTemplate(