test(integration-karma): template expressions

packages/@lwc/integration-karma/scripts/karma-plugins/lwc.js

@@ -41,6 +41,9 @@ function createPreprocessor(config, emitter, logger) {
             .join('\n');
         const outro = ancestorDirectories.map(() => `});`).join('\n');
 
+        // TODO [#3370]: remove experimental template expression flag
+        const experimentalComplexExpressions = suiteDir.includes('template-expressions');
+
         const plugins = [
             lwcRollupPlugin({
                 sourcemap: true,
@@ -50,6 +53,7 @@ function createPreprocessor(config, emitter, logger) {
                 },
                 enableLwcSpread: true,
                 enableDynamicComponents: true,
+                experimentalComplexExpressions,
                 disableSyntheticShadowSupport: DISABLE_SYNTHETIC_SHADOW_SUPPORT_IN_COMPILER,
             }),
         ];

packages/@lwc/integration-karma/test/template-expressions/errors/index.spec.js

@@ -0,0 +1,16 @@
+import { createElement } from 'lwc';
+
+import UndefinedMemberExpressionObjParent from 'x/undefinedMemberExpressionObjParent';
+import ThrowDuringCallParent from 'x/throwDuringCallParent';
+
+it(`should handle member expression with undefined object`, () => {
+    const parent = createElement('x-parent', { is: UndefinedMemberExpressionObjParent });
+    document.body.appendChild(parent);
+    expect(parent.caughtError).toContain('undefined');
+});
+
+it(`should handle errors thrown during call expression`, () => {
+    const parent = createElement('x-parent', { is: ThrowDuringCallParent });
+    document.body.appendChild(parent);
+    expect(parent.caughtError).toContain("I'm the Gingerbread man!");
+});

packages/@lwc/integration-karma/test/template-expressions/errors/x/throwDuringCallChild/throwDuringCallChild.html

@@ -0,0 +1,3 @@
+<template>
+    <div foo={runRunAsFastAsYouCan()}></div>
+</template>

packages/@lwc/integration-karma/test/template-expressions/errors/x/throwDuringCallChild/throwDuringCallChild.js

@@ -0,0 +1,7 @@
+import { LightningElement } from 'lwc';
+
+export default class Test extends LightningElement {
+    runRunAsFastAsYouCan() {
+        throw new Error("You can't catch me, I'm the Gingerbread man!");
+    }
+}

packages/@lwc/integration-karma/test/template-expressions/errors/x/throwDuringCallParent/throwDuringCallParent.html

@@ -0,0 +1,3 @@
+<template>
+    <x-throw-during-call-child></x-throw-during-call-child>
+</template>

packages/@lwc/integration-karma/test/template-expressions/errors/x/throwDuringCallParent/throwDuringCallParent.js

@@ -0,0 +1,8 @@
+import { LightningElement, api } from 'lwc';
+
+export default class Parent extends LightningElement {
+    @api caughtError = null;
+    errorCallback(err) {
+        this.caughtError = err.message;
+    }
+}

packages/@lwc/integration-karma/test/template-expressions/errors/x/undefinedMemberExpressionObjChild/undefinedMemberExpressionObjChild.html

@@ -0,0 +1,3 @@
+<template>
+    <div foo={nonexistent.thing}></div>
+</template>

packages/@lwc/integration-karma/test/template-expressions/errors/x/undefinedMemberExpressionObjChild/undefinedMemberExpressionObjChild.js

@@ -0,0 +1,3 @@
+import { LightningElement } from 'lwc';
+
+export default class Test extends LightningElement {}

packages/@lwc/integration-karma/test/template-expressions/errors/x/undefinedMemberExpressionObjParent/undefinedMemberExpressionObjParent.html

@@ -0,0 +1,3 @@
+<template>
+    <x-undefined-member-expression-obj-child></x-undefined-member-expression-obj-child>
+</template>

packages/@lwc/integration-karma/test/template-expressions/errors/x/undefinedMemberExpressionObjParent/undefinedMemberExpressionObjParent.js

@@ -0,0 +1,8 @@
+import { LightningElement, api } from 'lwc';
+
+export default class Parent extends LightningElement {
+    @api caughtError = null;
+    errorCallback(err) {
+        this.caughtError = err.message;
+    }
+}

packages/@lwc/integration-karma/test/template-expressions/smoke-test/index.spec.js

@@ -0,0 +1,10 @@
+import { createElement } from 'lwc';
+
+import Test from 'x/test';
+
+it(`should support call expressions`, () => {
+    const elm = createElement('x-test', { is: Test });
+    document.body.appendChild(elm);
+
+    expect(elm.shadowRoot.querySelector('div').getAttribute('foo')).toBe('bar');
+});

packages/@lwc/integration-karma/test/template-expressions/smoke-test/x/test/test.html

@@ -0,0 +1,3 @@
+<template>
+    <div foo={bar()}></div>
+</template>

packages/@lwc/integration-karma/test/template-expressions/smoke-test/x/test/test.js

@@ -0,0 +1,7 @@
+import { LightningElement } from 'lwc';
+
+export default class Test extends LightningElement {
+    bar() {
+        return 'bar';
+    }
+}