Fix decorators on windows by adjusting implicit jest path based on OS

[ThomasRooney]

The green/red dots are currently broken on windows if jest path isn't configured.

The jest path selected is always a shell jest (linux/mac) script, rather than a feature based on current operating system, and potentially running the jest.cmd file. As such it crashes when attempting to run in windows ENOENT, because windows cannot evaluate shell scripts.

This fixes that.

• Removed double default configuration in package.json and in pathToJest helper
• Check for OS platform before deciding on which script to run
• Assumes global jest if jest not in node_modules.

Not tested on Mac/Linux. Please confirm this doesn't regress there if you decide to merge.

This closes quite a few bugs that are correlated because the jest --getConfig command wasn't working on windows. FYI for a current workaround, just define jest path explicitly.

Closes #274 #320 #306 #289

[coveralls]

Pull Request Test Coverage Report for Build 357

• 1 of 8 (12.5%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-1.06%) to 74.168%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/helpers.ts	1	8	12.5%

Files with Coverage Reduction	New Missed Lines	%
src/helpers.ts	2	39.29%

Totals
Change from base Build 353:	-1.06%
Covered Lines:	570
Relevant Lines:	734

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💛 - Coveralls

[orta]

Yeah, cool, this looks 👍 to me - thanks!

[stephtr]

I think in the end that differentiation between Windows and Unix shouldn't be necessary if jest runs in a shell everywhere. Maybe even #297 would fix the problem (and would also fix #313), that PR however still waits for a new release of Jest.

[seanpoulter]

What's your intention for changing this line @ThomasRooney? It seems to me like we've changed it from "if this is still the default setting" to "if the default setting has changed".

[ThomasRooney]

I removed the default setting for pathToJest From the package.json. I did this because I didn’t want to break any user configuration where they’d predefined it, but the default pathToJest defined before was incorrect for windows systems (forcing Windows users to explicitly define it).

With pathToJest now potentially being null, I wanted to maintain old behaviour for linux/osx users, and my interpretation is that each code path used for the old version is equivalent in the new version, but for the windows scenario. In this particular line, I’m mapping the path !== defaultPath scenario for OSX users, which returned normalize(pluginSettings.pathToJest).

[ThomasRooney]

E.g. path === defaultPath => either npm test — or normalize(‘node_modules/.bin/jest’)
path !== defaultPath => normalize(path)

[stephtr]

One serious effect of that change is, that the detection for CRA apps now only takes place, when jest.pathToJest is already manually set, by default it fails!
As #297 finally fixes #274 I would revert or further update pathToJest (as done within #297).

[ThomasRooney]

@stephtr good point! This additional condition came from path === defaultPath && isBootstrappedWithCRA(pluginSettings.rootPath) but the path === defaultPath is equivalent to path not being predefined, instead of path being predefined. The CRA condition should be taken outside the nested if.

However my understanding of #297 is it would break windows again, because even if jest supports a different shell, the node_modules/.bin/jest is the bootstrap of jest that we invoke, and requires be run in a bourne-complaint shell (i.e. it will crash if run as a windows bat file). Please correct me if I'm wrong?

[stephtr]

By starting the commands in a Windows cmd (simply by supplying { shell: useShell }), running node_modules/.bin/jest automatically runs node_modules\.bin\jest.cmd (that's the same as omitting the .exe extension of a file when running it). The issue was that the runner itself ran the command in a cmd, but not the settings when fetching Jest's configuration after launch.

[seanpoulter]

I’ve got a PR in progress if you can wait another half day. 🐌