René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Incorrect resolution of CJS types from dual-package dependency in multi-project build with mixed `ESNext/Bundler` and `NodeNext` modules","articleBody":"### 🔎 Search Terms\n\n\"NodeNext\", \"ESNext\", \"Bundler\", \"module\", \"moduleResolution\", \"ESM\", \"CJS\", \"multi-project\", \"dual package\"\n\n### 🕗 Version \u0026 Regression Information\n\n- This is the behavior in every version I tried (5.0.4, 5.1.6, 5.2.2, 5.3.3, and 5.5.0-dev.20240226), and I reviewed the FAQ for entries about ESM\r\n\n\n### ⏯ Playground Link\n\nhttps://github.com/haines/typescript-dual-package-esnext-bundler-nodenext\n\n### 💻 Code\n\nIt's probably less confusing to look at the repo, sorry 🙈 I've tried to make it as minimal as possible.\r\n\r\nThis bug occurs in a multi-project build where one project (`app`) is configured to use `ESNext` module and `Bundler` module resolution, and another (`lib`) is using `NodeNext`. Everything is set up to use ESM with `\"type\": \"module\"` in package.json.\r\n\r\nIf both projects depend on the same dual-packaged dependency (`dep`), then when `app` imports `dep` directly, TypeScript correctly resolves the ESM types. However, transitive imports of `dep` through `lib` are resolved to the CJS types.\n\n### 🙁 Actual behavior\n\nTypeScript resolves the CJS types for transitive imports of the dual-packaged dependency. If the CJS types are not perfectly compatible with the ESM types, then this causes compile errors.\n\n### 🙂 Expected behavior\n\nTypeScript resolves the ESM types for all imports of the dual-packaged dependency.\n\n### Additional information about the issue\n\nOriginally encountered in `@bufbuild/protobuf`: https://github.com/bufbuild/protobuf-es/issues/718\r\n\r\nOur `app` is full-stack and built with Vite, which is why we want to use `ESNext/Bundler`, but our `lib` is consumed by other Node.js-only projects that are built with tsc and therefore it makes sense for that to be built with `NodeNext`.","author":{"url":"https://github.com/haines","@type":"Person","name":"haines"},"datePublished":"2024-02-26T21:39:42.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/57553/TypeScript/issues/57553"}