rusackas commented on code in PR #45595: URL: https://github.com/apache/superset/pull/45595#discussion_r4381138189
########## superset-frontend/spec/helpers/swcJestTransformer.js: ########## @@ -0,0 +1,147 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +import { createTransformer as createSwcTransformer } from '@swc/jest'; + +/** + * Jest transformer: @swc/jest plus one post-processing step. + * + * SWC's CommonJS output defines every ESM export as a lazy, non-configurable + * getter, which is why `jest.spyOn(module, 'name')` and + * `jest.replaceProperty(module, 'name', value)` throw "Cannot redefine + * property" on anything SWC transformed. Babel's output defined plain + * properties, so the suite relies on spying on module exports everywhere. + * This wrapper marks those getters `configurable: true` so the spies keep + * working, while leaving the getters lazy (an eager rewrite would break + * modules that import each other in a cycle). + * + * The second difference is what a module in an import cycle sees when it + * reads an export that has not been initialised yet. Babel assigns + * `exports.name = void 0` up front, so the read yields `undefined`; SWC's + * getter returns the live binding and throws a ReferenceError (temporal dead + * zone) instead. Several suites spread `jest.requireActual()` of a module + * that is still mid-evaluation, so the getters are made lenient to match + * Babel: an uninitialised export reads as `undefined`. + */ +// SWC keeps a leading comment of a default export inside the call, as +// `Object.defineProperty(exports, /** ... */ "default", {` or +// `Object.defineProperty(exports, // ...\n"default", {`, hence the optional +// block or line comments before the name. +const COMMENTS = String.raw`(?:(?:\/\*[\s\S]*?\*\/|\/\/[^\n]*)\s*)*`; +const DESCRIPTOR_HEAD = String.raw`Object\.defineProperty\((?:target, name|to, k|exports,\s*${COMMENTS}"[^"]+")`; +const EXPORT_GETTER_DESCRIPTOR = new RegExp( + String.raw`(${DESCRIPTOR_HEAD}, \{\s*enumerable: true,)(\s*)(get:)`, + 'g', +); +// A direct `Object.defineProperty(exports, "name", { enumerable, get` export +// (no `_export(` call), as emitted for single-export modules. +const DIRECT_EXPORT_GETTER = new RegExp( + String.raw`Object\.defineProperty\(exports,\s*${COMMENTS}"(?!__esModule")[^"]+", \{\s*enumerable: true,\s*get\b`, +); +// `_export(exports, { get name () { return binding; }, ... });` is how SWC +// declares named exports; the leniency below is scoped to this block and to +// the `Object.defineProperty(exports, ...)` descriptors, never to getters in +// application code. +const EXPORT_BLOCK = /_export\(exports, \{[\s\S]*?\n\}\);/g; +const EXPORT_BLOCK_GETTER = + /(get [\w$]+ \(\) \{\s*)return ([\w$]+(?:\.[\w$]+)*);/g; Review Comment: Done in 5eb03c22ad: the named-export getter pattern now allows the same comment group between `get` and the name, with a test for a commented default beside named exports. ########## superset-frontend/spec/helpers/swcJestTransformer.test.js: ########## @@ -0,0 +1,211 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +import { mirrorBabelExportSemantics } from './swcJestTransformer'; + +// The export-helper text is interpolated so this file is not itself rewritten +// by the transformer when Jest loads it; the fixtures stay raw SWC-shaped input. +const EXPORT_FN = '_export'; +const DEFINE = 'defineProperty'; +const GET = 'get'; +const helper = `function ${EXPORT_FN}(target, all) { + for(var name in all)Object.${DEFINE}(target, name, { + enumerable: true, + ${GET}: Object.getOwnPropertyDescriptor(all, name).get + }); +}`; +const exportsBlock = body => `${EXPORT_FN}(exports, { +${body} +});`; + +const NAMED_EXPORTS = `"use strict"; +Object.${DEFINE}(exports, "__esModule", { + value: true +}); +${helper} +${exportsBlock(` ${GET} answer () { + return answer; + }`)} +const answer = 42; +`; + +function load(code) { + const mod = { exports: {} }; + // eslint-disable-next-line no-new-func + new Function('module', 'exports', code)(mod, mod.exports); + return mod.exports; +} + +test('named exports become configurable so jest.spyOn works', () => { + const exports = load(mirrorBabelExportSemantics(NAMED_EXPORTS)); + expect(Object.getOwnPropertyDescriptor(exports, 'answer')).toMatchObject({ + configurable: true, + }); + expect(exports.answer).toBe(42); +}); + +test('an uninitialised export reads as undefined instead of throwing', () => { + const code = NAMED_EXPORTS.replace( + 'const answer = 42;', + 'globalThis.__read = exports.answer;\nlet answer = 42;', + ); + load(mirrorBabelExportSemantics(code)); + expect(globalThis.__read).toBeUndefined(); + delete globalThis.__read; +}); + +test('throws when an export shape is not recognised', () => { + const unknown = `_export(foo, {}); +Object.defineProperty(foo, "x", { + enumerable: true, + get: function() { return 1; } +});`; + expect(() => mirrorBabelExportSemantics(unknown)).toThrow( + /did not match any known shape/, + ); +}); + +test('throws when named export getters change shape but the helper still matches', () => { + const changed = `${helper} +${exportsBlock(` ${GET} answer() { return answer; }`)} +const answer = 42;`; + expect(() => mirrorBabelExportSemantics(changed)).toThrow( + /named export getters did not match/, + ); +}); + +test('member-expression and $-named getters are wrapped leniently', () => { + const code = `"use strict"; +${helper} +const dep = { bar: 7 }; +${exportsBlock(` ${GET} $value () { + return $value; + }, + ${GET} bar () { + return dep.bar; + }`)} +globalThis.__read = [exports.$value, exports.bar]; +let $value = 1; +`; + const patched = mirrorBabelExportSemantics(code); + expect(patched.match(/try \{ return/g)).toHaveLength(2); + load(patched); + expect(globalThis.__read).toEqual([undefined, 7]); + delete globalThis.__read; +}); + +test('a line-commented default export is configurable and lenient', () => { + const code = `"use strict"; +Object.${DEFINE}(exports, "__esModule", { + value: true +}); +globalThis.__read = exports.default; +Object.${DEFINE}(exports, // Wrap in memo +"default", { + enumerable: true, + ${GET}: function() { + return _default; + } +}); +const _default = 5; +`; + const patched = mirrorBabelExportSemantics(code); + expect(patched).toContain('try { return _default;'); + const exports = load(patched); + expect(globalThis.__read).toBeUndefined(); + delete globalThis.__read; + expect(Object.getOwnPropertyDescriptor(exports, 'default')).toMatchObject({ + configurable: true, + }); + expect(exports.default).toBe(5); +}); + +test('a doc-commented default export is configurable and lenient', () => { + const code = `Object.${DEFINE}(exports, /** doc */ "default", { + enumerable: true, + ${GET}: function() { + return _default; + } +}); +const _default = 5; +`; + const patched = mirrorBabelExportSemantics(code); + expect(patched).toContain('try { return _default;'); + expect( + Object.getOwnPropertyDescriptor(load(patched), 'default'), + ).toMatchObject({ configurable: true }); +}); + +test('a from[k] re-export is configurable and lenient', () => { Review Comment: Added all three in 5eb03c22ad: a `TypeError` from a re-exported getter propagates, an ordinary getter outside the export block still throws its `ReferenceError`, and the early read now happens after the descriptor is installed. -- This is an automated message from the Apache Git Service. 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