Example:

//@Filename: /tsconfig1.json{"compilerOptions":{"strictNullChecks":true}}//@Filename: /tsconfig2.json{"compilerOptions":{"noImplicitAny":true}}//@Filename: /tsconfig.json{"extends":["./tsconfig1.json","./tsconfig2.json"]"files":["./index.ts"]}//@Filename: /index.tsfunctionf(x){}// noImplicitAny errorlety:string;y.toLowerCase();// strictNullChecks error

@andrewbranch the compiler tests are hard to add with tsconfig.https://github.com/microsoft/TypeScript/pull/50403/files#diff-0556827a3985d4ffd3ed2e51ac63c9d86ba98ab41dca5c7711fb2750188cbe8a shows the test case where multiple tsconfigs are working together ?https://github.com/microsoft/TypeScript/pull/50403/files#diff-97bc6a439e0f02498deab0f7c919e4e7a2f06c6b4832fd2fc7b042f56b141ff9R111 baseline.

While said that we could add test in non watch mode as well.

I saw that baseline, but I couldn’t find any indication in the baseline that the options in the extended configs were relevant. I was looking for astrictNullChecks ornoImplicitAny error but didn’t see any. Maybe I missed it in the noise.

There are plenty of compiler tests with tsconfig files, but I don’t know if there are subtle gotchas with them.

@navya9singh you probably want to add test likehttps://github.com/microsoft/TypeScript/blob/main/src/testRunner/unittests/tsc/forceConsistentCasingInFileNames.ts with the contents of test files as shown by@andrewbranch for better clarity

@typescript-bot pack this

Heya@DanielRosenwasser, I've started to run the tarball bundle task on this PR atbb0ae2f. You can monitor the buildhere.

Hey@DanielRosenwasser, I've packed this intoan installable tgz. You can install it for testing by referencing it in yourpackage.json like so:

{    "devDependencies": {        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/139933/artifacts?artifactName=tgz&fileId=43D4A075BE928283C15303888F67D4786C1B8B67071DA37D39B422AFBEEC049702&fileName=/typescript-5.0.0-insiders.20221207.tgz"    }}

and then runningnpm install.

There is also a playgroundfor this build and annpm module you can use via"typescript": "npm:@typescript-deploys/pr-build@5.0.0-pr-50403-6".;

It looks like some changes landed inmain that require you to update something in your unit tests. I’m guessing it’s#51798. You’ll want to manually mergemain into this branch and then take a look at those test files that no longer build, using Sheetal’s PR as a reference for how to update them.

Very cool

Just a heads up if you're sharing atsconfig from a package. It seemstypescript@4.9.5 was not restricted by theexports from thepackage.json file. It is now with@typescript@5.0.3.

Thetsconfig.json file not found error was the last error when runningtsc.

In my case, it was also causingeslint (with@typescript-eslint/parser) to fail with out of memory errors. Since we runeslint beforetsc, it was a few tries before I decided to skipeslint and runtsc and was able to find the problem.