rusackas commented on code in PR #45595: URL: https://github.com/apache/superset/pull/45595#discussion_r4367606881
########## superset-frontend/spec/helpers/swcJestTransformer.js: ########## @@ -0,0 +1,103 @@ +/** + * 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 doc comment of a default export inside the call, as +// `Object.defineProperty(exports, /** ... */ "default", {`, hence the optional +// block comment before the name. +const EXPORT_GETTER_DESCRIPTOR = + /(Object\.defineProperty\((?:target, name|to, k|exports,\s*(?:\/\*[\s\S]*?\*\/\s*)?"[^"]+"), \{\s*enumerable: true,)(\s*)(get:)/g; +// `_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+);/g; +// The `get: function() { return binding; }` form SWC uses for a single export +// or a re-export (`from[k]`), matched together with its descriptor. +const EXPORT_DESCRIPTOR_GETTER = + /(Object\.defineProperty\((?:target, name|to, k|exports,\s*(?:\/\*[\s\S]*?\*\/\s*)?"[^"]+"), \{\s*enumerable: true,\s*)(get: function\(\) \{\s*)return (\w+|from\[k\]);/g; + +// Only a TDZ ReferenceError is swallowed; any other error still propagates. +const lenient = binding => + `try { return ${binding}; } catch (e) { if (!(e instanceof ReferenceError)) throw e; return undefined; }`; Review Comment: Added an istanbul ignore hint on the injected try/catch so it no longer reports uncovered branches. ########## superset-frontend/spec/helpers/swcJestTransformer.js: ########## @@ -0,0 +1,103 @@ +/** + * 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 doc comment of a default export inside the call, as +// `Object.defineProperty(exports, /** ... */ "default", {`, hence the optional +// block comment before the name. +const EXPORT_GETTER_DESCRIPTOR = + /(Object\.defineProperty\((?:target, name|to, k|exports,\s*(?:\/\*[\s\S]*?\*\/\s*)?"[^"]+"), \{\s*enumerable: true,)(\s*)(get:)/g; +// `_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+);/g; +// The `get: function() { return binding; }` form SWC uses for a single export +// or a re-export (`from[k]`), matched together with its descriptor. +const EXPORT_DESCRIPTOR_GETTER = + /(Object\.defineProperty\((?:target, name|to, k|exports,\s*(?:\/\*[\s\S]*?\*\/\s*)?"[^"]+"), \{\s*enumerable: true,\s*)(get: function\(\) \{\s*)return (\w+|from\[k\]);/g; + +// Only a TDZ ReferenceError is swallowed; any other error still propagates. +const lenient = binding => + `try { return ${binding}; } catch (e) { if (!(e instanceof ReferenceError)) throw e; return undefined; }`; + +function mirrorBabelExportSemantics(code) { + return code + .replace( + EXPORT_DESCRIPTOR_GETTER, + (_m, head, getter, binding) => `${head}${getter}${lenient(binding)}`, + ) + .replace(EXPORT_BLOCK, block => + block.replace( + EXPORT_BLOCK_GETTER, + (_m, head, binding) => `${head}${lenient(binding)}`, + ), + ) + .replace(EXPORT_GETTER_DESCRIPTOR, '$1 configurable: true,$2$3'); +} + +function patch(result) { + if (typeof result === 'string') return mirrorBabelExportSemantics(result); + return { ...result, code: mirrorBabelExportSemantics(result.code) }; +} + +const withPatch = + fn => + (...args) => { + const result = fn(...args); + return result && typeof result.then === 'function' + ? result.then(patch) + : patch(result); + }; + +// Bump when the post-processing changes so cached transforms are invalidated. +const CACHE_SALT = 'babel-export-semantics-v4'; Review Comment: Added a small test that runs sample SWC output through the transformer, and the transform now throws if an export block is present but nothing got rewritten. -- This is an automated message from the Apache Git Service. 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