Running `ng test` in windows fails with EMFILE error

[filipesilva]

Running ng test on Windows, with admin permissions, on a newly generated project fails with a Error: EMFILE: too many open files error.

Running ng serve and ng test --build=false in separate works though.

/cc @wardbell

OS: Windows 10

$ ng --version
angular-cli: 1.0.0-beta.5
node: 5.11.1
os: win32 x64

Reproduction steps:

ng new project
cd project
ng test

Result:

filipe.silva@DESKTOP-7ND6T3R MINGW64 /E/dev/testing/project (master)
$ ng test
Built project successfully. Stored in "dist/".
\ BuildingThe Broccoli Plugin: [BroccoliTypeScriptCompiler] failed with:
Error: EMFILE: too many open files, open 'E:\dev\testing\project\tmp\broccoli_type_script_compiler-input_base_path-sdKfbqXb.tmp\0\src\tsconfig.json'
    at Error (native)
    at Object.fs.openSync (fs.js:584:18)
    at Object.fs.readFileSync (fs.js:431:33)
    at BroccoliTypeScriptCompiler._loadTsConfig (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:123:34)
    at BroccoliTypeScriptCompiler._createServiceHost (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:158:25)
    at BroccoliTypeScriptCompiler.build (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:41:12)
    at C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-caching-writer\index.js:152:21
    at lib$rsvp$$internal$$tryCatch (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1036:16)
    at lib$rsvp$$internal$$invokeCallback (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1048:17)
    at lib$rsvp$$internal$$publish (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1019:11)
    at lib$rsvp$asap$$flush (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1198:9)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)

The broccoli plugin was instantiated at:
    at BroccoliTypeScriptCompiler.Plugin (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-plugin\index.js:10:31)
    at BroccoliTypeScriptCompiler.CachingWriter [as constructor] (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-caching-writer\index.js:21:10)
    at BroccoliTypeScriptCompiler (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:26:49)
    at Angular2App._getTsTree (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:321:18)
    at Angular2App._buildTree (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:116:23)
    at new Angular2App (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:53:23)
    at module.exports (E:\dev\testing\project\angular-cli-build.js:6:10)
    at Class.module.exports.Task.extend.setupBroccoliBuilder (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\models\builder.js:55:19)
    at Class.module.exports.Task.extend.init (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\models\builder.js:89:10)
    at new Class (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\core-object\core-object.js:18:12)
    at Class.module.exports.Task.extend.run (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\tasks\build-watch.js:17:16)
    at C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\addon\ng2\commands\test.js:69:46
    at lib$rsvp$$internal$$tryCatch (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1036:16)
    at lib$rsvp$$internal$$invokeCallback (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1048:17)
    at lib$rsvp$$internal$$publish (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1019:11)
    at lib$rsvp$asap$$flush (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1198:9)


The Broccoli Plugin: [BroccoliTypeScriptCompiler] failed with:
Error: EMFILE: too many open files, open 'E:\dev\testing\project\tmp\broccoli_type_script_compiler-input_base_path-sdKfbqXb.tmp\0\src\tsconfig.json'
    at Error (native)
    at Object.fs.openSync (fs.js:584:18)
    at Object.fs.readFileSync (fs.js:431:33)
    at BroccoliTypeScriptCompiler._loadTsConfig (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:123:34)
    at BroccoliTypeScriptCompiler._createServiceHost (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:158:25)
    at BroccoliTypeScriptCompiler.build (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:41:12)
    at C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-caching-writer\index.js:152:21
    at lib$rsvp$$internal$$tryCatch (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1036:16)
    at lib$rsvp$$internal$$invokeCallback (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1048:17)
    at lib$rsvp$$internal$$publish (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1019:11)
    at lib$rsvp$asap$$flush (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1198:9)
    at _combinedTickCallback (internal/process/next_tick.js:67:7)
    at process._tickCallback (internal/process/next_tick.js:98:9)

The broccoli plugin was instantiated at:
    at BroccoliTypeScriptCompiler.Plugin (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-plugin\index.js:10:31)
    at BroccoliTypeScriptCompiler.CachingWriter [as constructor] (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\broccoli-caching-writer\index.js:21:10)
    at BroccoliTypeScriptCompiler (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\broccoli-typescript.js:26:49)
    at Angular2App._getTsTree (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:321:18)
    at Angular2App._buildTree (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:116:23)
    at new Angular2App (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\lib\broccoli\angular2-app.js:53:23)
    at module.exports (E:\dev\testing\project\angular-cli-build.js:6:10)
    at Class.module.exports.Task.extend.setupBroccoliBuilder (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\models\builder.js:55:19)
    at Class.module.exports.Task.extend.init (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\models\builder.js:89:10)
    at new Class (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\core-object\core-object.js:18:12)
    at Class.module.exports.Task.extend.run (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\angular-cli\lib\tasks\build-watch.js:17:16)
    at C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\addon\ng2\commands\test.js:69:46
    at lib$rsvp$$internal$$tryCatch (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1036:16)
    at lib$rsvp$$internal$$invokeCallback (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1048:17)
    at lib$rsvp$$internal$$publish (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1019:11)
    at lib$rsvp$asap$$flush (C:\Users\filipe.silva\AppData\Roaming\nvm\v5.11.1\node_modules\angular-cli\node_modules\rsvp\dist\rsvp.js:1198:9)

[Foxandxss]

Yup, same error as Ward's.

My question is: If ng serve builds the project succesfully, why ng test doesn't? Are they building in a different way?

[filipesilva]

They might, yes. Investigating.

[filipesilva]

Possibly related: angular/angular#4525

[filipesilva]

The explanation for why ng test fails but serving and testing works seems to be that individual processes have a file descriptor limit (see http://stackoverflow.com/questions/31932729/open-too-many-files-emfile-error-in-windows-7). Thus running in separate doubles the file limit.

[filipesilva]

Further investigation shows that the problem occurs because of karma serving the files in dist/vendor/.

Effectively, the process is watching those files files twice - once for rebuilding them and once for testing them.

I don't have a solution for this at the moment.

[JohannesHoppe]

FYI, I changed my "test" npm-script to:
ng build && ng test --build=false

That's a good workaround until this is fixed.

[filipesilva]

@JohannesHoppe your solution is better than the one I put up in https://github.com/angular/angular-cli/pull/991/files. Would you be interested in making a PR replacing my warning?

[JohannesHoppe]

Sure, I'll do that. 😄

[Blasz]

I think it should be ng build && ng test --build=false --watch=false. There isn't much point keeping the tester in watch mode if the sources don't rebuild.

I still think separate ng serve + ng test processes are good for running tests in watch mode whereas the npm script change is better for running it once.