TypeScript refuses to emit files from node_modules with getEmitOutput()

Hi. In out company we use workflow when all packages are written in pure TypeScript and we publish and consume them as-is, without any pre-compilation. I know that it’s slower, but it’s very convenient for developers, because they don’t need to run several parallel tsc --watch processes.

We used webpack and awesome-typescript-loader for this and everything worked fine. But I see that now TypeScript refuses to emit files from node_modules directory using getEmitOutput(), because of isSourceFileFromExternalLibrary check here.

Can we make this configurable?

[jjrv]

Outside node_modules TypeScript emits .js files for any .ts files I import, whether they’re listed under files in tsconfig.json or not. This is very nice.

I have a monorepo structured like boennemann/alle. It makes the monorepo very easy to work with, requiring minimal tooling. The trick is to place all code under node_modules so Node’s module lookup strategy will find them without having to create any symlinks.

Unfortunately I’m running into this issue… Now it’s necessary to either omit files, list all of them or use a wildcard. In this case there would be a reasonable strategy: when a .ts file included in files is located under node_modules then for any further .ts files it imports from the same directory or a subdirectory (without entering any deeper node_modules directories), a .js file should still be emitted.

Alternatively a configuration option in tsconfig.json listing paths where .js files should be emitted, whether under node_modules or not, should fix this issue for everyone’s possible use cases.

[ahnpnl]

@jjrv said it right. At the moment in ts-jest, either ts-jest has to use Program as fallback or read jest config to solve the issue. I hope TypeScript can solve this natively.