René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Version 22.20.0 tightens Module Loader ?","articleBody":"### Version\n\n22.20.0 LTS\n\n### Platform\n\n```text\nDarwin M-ldkfj2929292 24.6.0 Darwin Kernel Version 24.6.0: Mon Aug 11 21:16:34 PDT 2025; root:xnu-11417.140.69.701.11~1/RELEASE_ARM64_T6020 arm64\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\nbefore 22.20.0 upgrade, we had 22.17.1 and our script configuration was working correctly.\n\nThe line of code (script block, and the affected line respecr) - with 22.17.1\n\n\n`\"test\": \"cd ../../ \u0026\u0026 jest --verbose --testPathPatterns=packages/platform-tooling\"`\n\n`moduleNameMapper: {\n        '^uuid$': require.resolve('uuid'),\n        ...\n      },`\n\nAfter upgrading to node 22.20.0 - we are seeing the following error stack when that uuid module is being loaded(uuid package version hasn't changed)\n\n`Error: Jest: Failed to parse the TypeScript config file /Users/dumb-user/mockingbird/jest.config.ts\n\n  ReferenceError: require is not defined in ES module scope, you can use import instead\n\n    at readConfigFileAndSetRootDir (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/jest-config/build/index.js:2258:13)\n\n    at async readInitialOptions (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/jest-config/build/index.js:1147:13)\n\n    at async readConfig (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/jest-config/build/index.js:918:7)\n\n    at async readConfigs (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/jest-config/build/index.js:1168:26)\n\n    at async runCLI (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/@jest/core/build/index.js:1393:7)\n\n    at async Object.run (/Users/dumb-user/mockingbird/packages/platform-tooling/node_modules/jest-cli/build/index.js:656:9)`\n\n🤔 Why does this happen? And here is my stupid theory (please rebut and let me know the root cause)\n\n1. Node v22.20.0 tightened its module loader so a require() on a .ts file now throws ERR_REQUIRE_ESM whenever the file is treated as an ES module. That change comes from the work introducing the native TypeScript loader (--experimental-strip-types) described in the v22.6.0+ release notes on nodejs.org; the loader defaults .ts to ESM, so plain require() is rejected (?)\n\n2. When Jest tries to load `jest.config.ts`, it calls require(configPath). Since Node 22.20 reports ERR_REQUIRE_ESM, the code in node_modules/jest-config/build/readConfigFileAndSetRootDir.js falls back to await import(configPath). Inside that ESM evaluation require is not defined, so the line `^uuid$': require.resolve('uuid')` immediately throws the “ReferenceError: require is not defined in ES module scope” you’re seeing(?)\n\n\nHope this makes sense. And thanks in advance for looking into it. \n\n\n\n### How often does it reproduce? Is there a required condition?\n\nImmediately after moving from 22.17.1 to 22.20.0 \n\n### What is the expected behavior? Why is that the expected behavior?\n\nNo change in behaviour in any minor/patch version released. Not at least for tightening ESM vs. CJS expectations.\n\n### What do you see instead?\n\nAs reported above in stack trace.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/mohammedmanna-skyscanner","@type":"Person","name":"mohammedmanna-skyscanner"},"datePublished":"2025-10-17T10:52:45.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/60290/node/issues/60290"}