tsc includes previous output in result when allowJs is enabled and "exclude" is non-empty

TypeScript Version: 2.7.0-dev.20171222

Code

For easy access, clone this gist: https://gist.github.com/WasabiFan/6922d6eb6224945ac809c216fdc37089

test.ts:

// Source code here

tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "outDir": "out",
    "allowJs": true
  },
  "exclude": [
    "node_modules"
  ]
}

Removing the exclude block or disabling allowJs avoids the issue.

Note that this is an easy state to get into: in my case, I generated a VSCode extension with their official templates and then enabled allowJs. I didn't realize what was going on until my PC ran out of RAM, as it automatically ran the watch task and the depth grew every time I saved.

Expected behavior:

I can compile the project with tsc as many times as I'd like.

Actual behavior:

PS D:\...> git clone https://gist.github.com/WasabiFan/6922d6eb6224945ac809c216fdc37089 tsc-recursion-demo-gist
Cloning into 'tsc-recursion-demo-gist'...
remote: Counting objects: 7, done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 7 (delta 1), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (7/7), done.
PS D:\...> cd .\tsc-recursion-demo-gist\
PS D:\...\tsc-recursion-demo-gist> tsc -p .
PS D:\...\tsc-recursion-demo-gist> tsc -p .
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/test.js' because it would overwrite input file.
PS D:\...\tsc-recursion-demo-gist> tsc -p .
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/test.js' because it would overwrite input file.
PS D:\...\tsc-recursion-demo-gist> tsc -p .
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/test.js' because it would overwrite input file.
PS D:\...\tsc-recursion-demo-gist> tsc -p .
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/test.js' because it would overwrite input file.
PS D:\...\tsc-recursion-demo-gist> tsc -p .
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/out/test.js' because it would overwrite input file.
error TS5055: Cannot write file 'D:/.../tsc-recursion-demo-gist/out/test.js' because it would overwrite input file.

The fix (and the best option) is to exclude the output directory. But given that existing templates don't do that, I think this is a significant issue. I don't understand why this doesn't happen when the exclude block is removed; I assume there's an internal safety to prevent this problem that's overridden.

Clonez le gist lié et reproduisez le problème avec test.ts et tsconfig.json, en utilisant allowJs, un exclude non vide et outDir. Commencez par suivre la découverte des entrées du projet et le comportement des exécutions répétées de tsc -p. C’est terminé lorsque les compilations répétées n’incluent plus les sorties précédentes sous out/ comme nouvelles entrées et ne produisent plus de chemins de sortie récursifs.