polymer-build/lib/test/js-transform_test.js

"use strict";
/**
 * @license
 * Copyright (c) 2018 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at
 * http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at
 * http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at
 * http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at
 * http://polymer.github.io/PATENTS.txt
 */
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
const chai_1 = require("chai");
const path = require("path");
const stripIndent = require("strip-indent");
const js_transform_1 = require("../js-transform");
const util_1 = require("./util");
suite('jsTransform', () => {
    const rootDir = path.join(__dirname, '..', '..', 'test-fixtures', 'npm-modules');
    const filePath = path.join(rootDir, 'foo.js');
    suite('compilation', () => {
        test('compiles to ES5 when compile=true', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = 3;', { compile: true }), 'var foo = 3;');
        });
        test('compiles to ES5 when compile=es5', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = 3;', { compile: 'es5' }), 'var foo = 3;');
        });
        test('compiles to ES2015 when compile=es2015', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('2 ** 5;', { compile: 'es2015' }), 'Math.pow(2, 5);');
        });
        test('compiles ES2017 to ES5', () => __awaiter(this, void 0, void 0, function* () {
            const result = js_transform_1.jsTransform('async function test() { await 0; }', { compile: 'es5' });
            chai_1.assert.include(result, '_asyncToGenerator');
            chai_1.assert.notInclude(result, 'async function test');
            chai_1.assert.include(result, 'regeneratorRuntime');
        }));
        test('compiles ES2017 to ES2015', () => __awaiter(this, void 0, void 0, function* () {
            const result = js_transform_1.jsTransform('async function test() { await 0; }', { compile: 'es2015' });
            chai_1.assert.include(result, 'asyncToGenerator');
            chai_1.assert.notInclude(result, 'async function test');
            chai_1.assert.notInclude(result, 'regeneratorRuntime');
        }));
        test('does not unnecessarily reformat', () => {
            // Even with no transform plugins, parsing and serializing with Babel will
            // make some minor formatting changes to the code, such as removing
            // trailing newlines. Check that we don't do this when no transformations
            // were configured.
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = 3;\n', {}), 'const foo = 3;\n');
        });
    });
    suite('minification', () => {
        test('minifies a simple expression', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = 3;', { minify: true }), 'const foo=3;');
        });
        test('minifies an exported const', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = "foo"; export { foo };', { minify: true }), 'const foo="foo";export{foo};');
        });
        test('minifies and compiles', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('const foo = 3;', { compile: true, minify: true }), 'var foo=3;');
        });
        test('minifies but does not try to remove dead code', () => {
            chai_1.assert.equal(js_transform_1.jsTransform('if (false) { never(); } always();', { minify: true }), 'if(!1){never()}always();');
        });
    });
    suite('babel helpers', () => {
        const classJs = `class MyClass {}`;
        const helperSnippet = `function _classCallCheck(`;
        test('inlined when external helpers are disabled', () => {
            const result = js_transform_1.jsTransform(classJs, { compile: true, externalHelpers: false });
            chai_1.assert.include(result, helperSnippet);
            chai_1.assert.include(result, 'MyClass');
        });
        test('omitted when external helpers are enabled', () => {
            const result = js_transform_1.jsTransform(classJs, { compile: true, externalHelpers: true });
            chai_1.assert.notInclude(result, helperSnippet);
            chai_1.assert.include(result, 'MyClass');
        });
    });
    suite('regenerator runtime', () => {
        const asyncJs = `async () => { await myFunction(); } `;
        const regeneratorSnippet = `regeneratorRuntime=`;
        test('inlined when external helpers are disabled', () => {
            const result = js_transform_1.jsTransform(asyncJs, { compile: 'es5', externalHelpers: false });
            chai_1.assert.include(result, regeneratorSnippet);
            chai_1.assert.include(result, 'myFunction');
        });
        test('omitted when external helpers are enabled', () => {
            const result = js_transform_1.jsTransform(asyncJs, { compile: 'es5', externalHelpers: true });
            chai_1.assert.notInclude(result, regeneratorSnippet);
            chai_1.assert.include(result, 'myFunction');
        });
        test('omitted when compile target is es2015', () => {
            const result = js_transform_1.jsTransform(asyncJs, { compile: 'es2015', externalHelpers: false });
            chai_1.assert.notInclude(result, regeneratorSnippet);
            chai_1.assert.include(result, 'myFunction');
        });
        test('omitted when code does not require it', () => {
            const result = js_transform_1.jsTransform(`class MyClass {}`, { compile: 'es5', externalHelpers: false });
            chai_1.assert.notInclude(result, regeneratorSnippet);
            chai_1.assert.include(result, 'MyClass');
        });
    });
    suite('parse errors', () => {
        const invalidJs = ';var{';
        test('throw when softSyntaxError is false', () => {
            chai_1.assert.throws(() => js_transform_1.jsTransform(invalidJs, { compile: true, softSyntaxError: false }));
        });
        test('do not throw when softSyntaxError is true', () => __awaiter(this, void 0, void 0, function* () {
            const output = yield util_1.interceptOutput(() => __awaiter(this, void 0, void 0, function* () {
                chai_1.assert.equal(js_transform_1.jsTransform(invalidJs, { compile: true, softSyntaxError: true }), invalidJs);
            }));
            chai_1.assert.include(output, '[polymer-build]: failed to parse JavaScript:');
        }));
    });
    suite('exponentiation', () => {
        const js = 'const foo = 2**2;';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'const foo=2**2;');
        });
        test('compiles to ES5', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { compile: true }), 'var foo = Math.pow(2, 2);');
        });
    });
    suite('rest properties', () => {
        const js = 'let { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 };';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'let{x,y,...z}={x:1,y:2,a:3,b:4};');
        });
        test('compiles to ES5', () => {
            chai_1.assert.include(js_transform_1.jsTransform(js, { compile: true }), 
            // Some compiled features are very verbose. Just look for the Babel
            // helper call so we know the plugin ran.
            'objectWithoutProperties');
        });
    });
    suite('spread properties', () => {
        const js = 'let n = { x, y, ...z };';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'let n={x,y,...z};');
        });
        test('compiles to ES5', () => {
            chai_1.assert.include(js_transform_1.jsTransform(js, { compile: true }), 'objectSpread');
        });
    });
    suite('async/await', () => {
        const js = 'async function foo() { await bar(); }';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'async function foo(){await bar()}');
        });
        test('compiles to ES5', () => {
            chai_1.assert.include(js_transform_1.jsTransform(js, { compile: true }), 'asyncToGenerator');
        });
    });
    suite('async generator', () => {
        const js = 'async function* foo() { yield bar; }';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'async function*foo(){yield bar}');
        });
        test('compiles to ES5', () => {
            chai_1.assert.include(js_transform_1.jsTransform(js, { compile: true }), 'wrapAsyncGenerator');
        });
    });
    suite('dynamic import', () => {
        const js = 'const foo = import("bar.js");';
        test('minifies', () => {
            chai_1.assert.equal(js_transform_1.jsTransform(js, { minify: true }), 'const foo=import("bar.js");');
        });
    });
    suite('rewrites bare module specifiers', () => {
        test('node packages', () => {
            const input = stripIndent(`
        import { dep1 } from 'dep1';
        import { dep2 } from 'dep2';
        import { dep2A } from 'dep2/a';
        import { dep3 } from 'dep3';
        import { dep4 } from 'dep4';
      `);
            const expected = stripIndent(`
        import { dep1 } from "./node_modules/dep1/index.js";
        import { dep2 } from "./node_modules/dep2/dep2.js";
        import { dep2A } from "./node_modules/dep2/a.js";
        import { dep3 } from "./node_modules/dep3/dep3-module.js";
        import { dep4 } from "./node_modules/dep4/dep4-module.js";
      `);
            const result = js_transform_1.jsTransform(input, { moduleResolution: 'node', filePath });
            chai_1.assert.equal(result.trim(), expected.trim());
        });
        test('regular paths and urls', () => {
            const input = stripIndent(`
        import { p1 } from '/already/a/path.js';
        import { p2 } from './already/a/path.js';
        import { p3 } from '../already/a/path.js';
        import { p4 } from '../already/a/path.js';
        import { p5 } from 'http://example.com/already/a/path.js';
      `);
            const expected = stripIndent(`
        import { p1 } from '/already/a/path.js';
        import { p2 } from './already/a/path.js';
        import { p3 } from '../already/a/path.js';
        import { p4 } from '../already/a/path.js';
        import { p5 } from 'http://example.com/already/a/path.js';
      `);
            const result = js_transform_1.jsTransform(input, { moduleResolution: 'node', filePath });
            chai_1.assert.equal(result.trim(), expected.trim());
        });
        test('paths that still need node resolution', () => {
            const input = 
            // Resolves to a .js file.
            `import { bar } from './bar';\n` +
                // Resolves to a .json file (invalid for the web, but we still do it).
                `import { baz } from './baz';\n` +
                // Resolves to an actual extension-less file in preference to a .js
                // file with the same basename.
                `import { qux } from './qux';\n`;
            const expected = stripIndent(`
        import { bar } from "./bar.js";
        import { baz } from "./baz.json";
        import { qux } from './qux';
      `);
            const result = js_transform_1.jsTransform(input, { moduleResolution: 'node', filePath });
            chai_1.assert.equal(result.trim(), expected.trim());
        });
        test('paths for dependencies', () => {
            const input = stripIndent(`
        import { dep1 } from 'dep1';
      `);
            const expected = stripIndent(`
        import { dep1 } from "../dep1/index.js";
      `);
            const result = js_transform_1.jsTransform(input, {
                moduleResolution: 'node',
                filePath,
                isComponentRequest: true,
                packageName: 'some-package',
                componentDir: path.join(rootDir, 'node_modules'),
                rootDir,
            });
            chai_1.assert.equal(result.trim(), expected.trim());
        });
        test('dependencies from a scoped package', () => {
            const input = stripIndent(`
        import { dep1 } from 'dep1';
      `);
            const expected = stripIndent(`
        import { dep1 } from "../../dep1/index.js";
      `);
            const result = js_transform_1.jsTransform(input, {
                moduleResolution: 'node',
                filePath,
                isComponentRequest: true,
                packageName: '@some-scope/some-package',
                componentDir: path.join(rootDir, 'node_modules'),
                rootDir,
            });
            chai_1.assert.equal(result.trim(), expected.trim());
        });
    });
    test('transforms ES modules to AMD', () => {
        const input = stripIndent(`
      import { dep1 } from 'dep1';
      export const foo = 'foo';
    `);
        const expected = stripIndent(`
      define(["exports", "dep1"], function (_exports, _dep) {
        "use strict";

        Object.defineProperty(_exports, "__esModule", {
          value: true
        });
        _exports.foo = void 0;
        const foo = 'foo';
        _exports.foo = foo;
      });
    `);
        const result = js_transform_1.jsTransform(input, {
            transformModulesToAmd: true,
            filePath,
            rootDir,
        });
        chai_1.assert.equal(result.trim(), expected.trim());
    });
    test('transforms import.meta', () => {
        const input = stripIndent(`
      console.log(import.meta);
    `);
        const expected = stripIndent(`
      define(["meta"], function (meta) {
        "use strict";

        meta = babelHelpers.interopRequireWildcard(meta);
        console.log(meta);
      });
    `);
        const result = js_transform_1.jsTransform(input, {
            transformModulesToAmd: true,
            externalHelpers: true,
        });
        chai_1.assert.equal(result.trim(), expected.trim());
    });
    test('transforms dynamic import()', () => {
        const input = stripIndent(`
      import { dep1 } from 'dep1';
      export const foo = 'foo';
      console.log(import('./bar.js'));
    `);
        const result = js_transform_1.jsTransform(input, {
            transformModulesToAmd: true,
            filePath,
            rootDir,
        });
        chai_1.assert.include(result, `define(["exports", "require", "dep1"], function (_exports, _require, _dep) {`);
        chai_1.assert.include(result, `console.log(new Promise((res, rej) => _require.default(['./bar.js'], res, rej)));`);
    });
    // https://github.com/babel/babel/pull/8501
    test('includes the native function check', () => {
        const input = stripIndent(`
      class TestElement extends HTMLElement {
        constructor() {
          super();
          this.x = 1234;
        }
      }

      window.customElements.define("test-element", TestElement);
    `);
        const result = js_transform_1.jsTransform(input, { compile: true });
        chai_1.assert.include(result, '_isNativeFunction');
    });
    // https://github.com/babel/minify/issues/824
    test('does not remove statements preceding certain loops', () => {
        const input = stripIndent(`
        let foo = 'bar';
        while (0);
        console.log(foo);
    `);
        const result = js_transform_1.jsTransform(input, { compile: true, minify: true });
        chai_1.assert.include(result, 'bar');
    });
});
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