fix(readFile): handle path doesn't exist error for new file

[joshwiens]

Please check if the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior? (You can also link to an open issue here)

With auto watch enabled, add a new test after the initial rest run and it will throw.

Reproducible here. Thanks @Silviu-Marian
https://github.com/Silviu-Marian/karma-webpack-pr69

What is the new behavior?

Added a try/catch clause to guard against a "Path doesn't exist" error
coming from MemoryFileSystem.prototype.readFileSync when a new file is
added to the file-system that matches the files glob.

Does this PR introduce a breaking change?

• Yes
• No

If this PR contains a breaking change, please describe the following...

• Impact:
• Migration path for existing applications:
• Github Issue(s) this is regarding:

Other information:

Closes #40
Closes #69

[radhikaa]

@d3viant0ne I am facing the same issue as mentioned above in my project. I have a file glob mentioned in the karma config. I have spec files created in my project that match this file pattern. When I run the tests, I get the "Path doesn't exist" error coming from MemoryFileSystem.prototype.readFileSync.

There are multiple solutions suggested in various links including:

1. change 'tests/**.spec.js' to '../tests/**spec.js' so that we come of the '_karma_webpack' path
2. do not set 'entry' for webpack in its config
3. use this method of creating a single entry point instead of file pattern and make changes to config accordingly

Unfortunately, none of these solutions are working for me.

I cannot capture the exact fix that you have posted for this issue. Could you suggest a way out of this problem?

[Silviu-Marian]

K:\www\wrk\amazingthings-web-app>npm update karma-webpack
[email protected] K:\www\wrk\amazingthings-web-app
`-- [email protected]

npm WARN optional Skipping failed optional dependency /chokidar/fsevents:
npm WARN notsup Not compatible with your operating system or architecture: [email protected]

K:\www\wrk\amazingthings-web-app>npm test

> [email protected] test K:\www\wrk\amazingthings-web-app
> nodemon --exitcrash -w karma.conf.js karma.js

[nodemon] 1.11.0

[nodemon] starting `node karma.js`enter `rs`
Happy[1]: Version: 3.0.2. Using cache? yes. Threads: 3
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
webpack: wait until bundle finished:
Happy[1]: Loaded 34 entries from cache. (0 were stale)
Happy[1]: All set; signalling webpack to proceed.
Build co 03 02 2017 11:17:17.810:INFO [PhantomJS 2.1.1 (Windows 8 0.0.0)]: Connected on socket /#gUMs_pt6iAnktTCGAAAA with id 95424312
PhantomJS 2.1.1 (Windows 8 0.0.0): Executed 32 of 32 SUCCESS (1.728 secs / 1.447 secs)
webpack: Compiling...

  build [=            ] 10%03 02 2017 11:18:39.803:ERROR [karma]: { Error: no such file or directory
    at MemoryFileSystem.readFileSync (K:\www\wrk\amazingthings-web-app\node_modules\memory-fs\lib\MemoryFileSystem.js:107:10)
    at MemoryFileSystem.(anonymous function) [as readFile] (K:\www\wrk\amazingthings-web-app\node_modules\memory-fs\lib\MemoryFileSystem.js:300:34)
    at doRead (K:\www\wrk\amazingthings-web-app\node_modules\karma-webpack\lib\karma-webpack.js:203:29)
    at Plugin.readFile (K:\www\wrk\amazingthings-web-app\node_modules\karma-webpack\lib\karma-webpack.js:208:7)
    at K:\www\wrk\amazingthings-web-app\node_modules\karma-webpack\lib\karma-webpack.js:233:19
    at nextPreprocessor (K:\www\wrk\amazingthings-web-app\node_modules\karma\lib\preprocessor.js:36:26)
    at K:\www\wrk\amazingthings-web-app\node_modules\karma\lib\preprocessor.js:122:9
    at module.exports (K:\www\wrk\amazingthings-web-app\node_modules\karma\node_modules\isbinaryfile\index.js:28:12)
    at K:\www\wrk\amazingthings-web-app\node_modules\karma\lib\preprocessor.js:84:7
    at K:\www\wrk\amazingthings-web-app\node_modules\karma\node_modules\graceful-fs\graceful-fs.js:78:16
    at FSReqWrap.readFileAfterClose [as oncomplete] (fs.js:445:3)
  code: 'ENOENT',
  errno: 34,
  message: 'no such file or directory',
  path: '/_karma_webpack_/v2/Components/Dropdown.spec.js' }
  build [=======      ] 50%[nodemon] app crashed

> [email protected] posttest K:\www\wrk\amazingthings-web-app
> npm run test

Looks like the problem is still here.
Using [email protected]