Enable mutation testing again on Stryker's own code

[bartekleon]

replacing stuff in github actions i realised that you can't run mutation testing anymore... it seems there are some problems with configurations:

@stryker-mutator/core: 14:33:11 (2884) INFO ConfigReader Using stryker.conf.js
@stryker-mutator/core: 14:33:11 (2884) INFO ConfigReader Stryker can help you setup a `stryker.conf` file for your project.
@stryker-mutator/core: 14:33:11 (2884) INFO ConfigReader Please execute `stryker init` in your project's root directory.
@stryker-mutator/core: 14:33:11 (2884) ERROR Stryker Invalid config file. Inner error: TypeError: Cannot set property 'module' of undefined
@stryker-mutator/core: TypeError: Cannot set property 'module' of undefined
@stryker-mutator/core:     at Object.<anonymous> (/home/runner/work/stryker/stryker/packages/core/stryker.conf.js:4:27)
@stryker-mutator/core:     at Module._compile (internal/modules/cjs/loader.js:1137:30)
@stryker-mutator/core:     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)
@stryker-mutator/core:     at Module.load (internal/modules/cjs/loader.js:985:32)
@stryker-mutator/core:     at Function.Module._load (internal/modules/cjs/loader.js:878:14)
@stryker-mutator/core:     at Module.require (internal/modules/cjs/loader.js:1025:19)
@stryker-mutator/core:     at require (internal/modules/cjs/helpers.js:72:18)
@stryker-mutator/core:     at ConfigReader.loadConfigModule (/home/runner/work/stryker/stryker/packages/core/src/config/ConfigReader.js:60:32)
@stryker-mutator/core:     at ConfigReader.readConfig (/home/runner/work/stryker/stryker/packages/core/src/config/ConfigReader.js:26:35)
@stryker-mutator/core:     at readConfig (/home/runner/work/stryker/stryker/packages/core/src/config/readConfig.js:7:25)

[bartekleon]

This part could be fixed by changing config file name or adding a parameter to CI. We handle stryker.conf... but ours is stryker.parent.conf so it doesn't see it.
Then there is a problem with dashboard option in core.
it could be solved by

settings.dashboard ? settings.dashboard.module = moduleName : settings.dashboard = { module: moduleName };

then problem with build...

settings.buildCommand = 'tsc -b && lerna run build';

then with tests - i can't actually solve this one...
error messages:

@stryker-mutator/core: > @stryker-mutator/core@4.0.0-beta.3 stryker C:\Users\groszek\Desktop\GitHub\stryker\packages\core
@stryker-mutator/core: > node bin/stryker run
@stryker-mutator/core: 17:44:25 (4396) INFO ConfigReader Using stryker.conf.js
@stryker-mutator/core: 17:44:25 (4396) INFO BroadcastReporter Detected that current console does not support the "progress" reporter, downgrading to "progress-append-only" reporter
@stryker-mutator/core: 17:44:25 (4396) WARN InputFileResolver Globbing expression "typings/**/*.ts" did not result in any files.
@stryker-mutator/core: 17:44:25 (4396) INFO InputFileResolver Found 103 of 188 file(s) to be mutated.
@stryker-mutator/core: 17:44:27 (4396) INFO Instrumenter Instrumented 103 source file(s) with 2817 mutant(s)
@stryker-mutator/core: 17:44:27 (4396) INFO ConcurrencyTokenProvider Creating 2 checker process(es) and 2 test runner process(es).
@stryker-mutator/core: 17:44:41 (4396) INFO Sandbox Running build command "tsc -b && lerna run build" in the sandbox at "C:\Users\groszek\Desktop\GitHub\stryker\packages\core\.stryker-tmp\sandbox8835757".
@stryker-mutator/core: 17:44:41 (4396) INFO DryRunExecutor Starting initial test run. This may take a while.
@stryker-mutator/core: 17:44:42 (4396) INFO DryRunExecutor Initial test run succeeded. Ran 0 tests in 17 seconds (net 0 ms, overhead 5 ms).
@stryker-mutator/core: 17:44:42 (4396) ERROR Stryker No tests were executed. Stryker will exit prematurely. Please check your configuration.

[nicojs]

Yeah, we didn't update the config for Running Stryker on Stryker. I've changed the title (because it's not an issue with Stryker itself).

[nicojs]

@stryker-mutator/core: 17:44:41 (4396) INFO Sandbox Running build command "tsc -b && lerna run build" in the sandbox at "C:\Users\groszek\Desktop\GitHub\stryker\packages\core.stryker-tmp\sandbox8835757".

That command actually failed, but because you're running on windows and nicojs/node-link-parent-bin#20 you don't notice it.

I think "tsc -b" should be the build command of a sub package.

[bartekleon]

@nicojs if you were able to fix it I would be grateful, these reports would be very handy in refactoring and optimising code :)

[nicojs]

I'm running into this issue:

nicojs@nicoj03:~/stryker/packages/core$ npm run stryker

> @stryker-mutator/core@4.0.0-beta.4 stryker /home/nicojs/stryker/packages/core
> node bin/stryker run

17:54:44 (15197) INFO ConfigReader Using stryker.conf.js
17:54:45 (15197) WARN InputFileResolver Globbing expression "typings/**/*.ts" did not result in any files.
17:54:45 (15197) INFO InputFileResolver Found 104 of 189 file(s) to be mutated.
17:54:49 (15197) INFO Instrumenter Instrumented 104 source file(s) with 2830 mutant(s)
17:54:50 (15197) INFO ConcurrencyTokenProvider Creating 2 checker process(es) and 2 test runner process(es).
17:54:52 (15197) INFO Sandbox Running build command "tsc -b" in the sandbox at "/home/nicojs/stryker/packages/core/.stryker-tmp/sandbox8668860".
17:55:16 (15197) ERROR Stryker an error occurred Error: Command failed with exit code 1: tsc -b
src/config/OptionsValidator.ts(108,13): error TS2578: Unused '@ts-expect-error' directive.
src/config/OptionsValidator.ts(120,312): error TS2578: Unused '@ts-expect-error' directive.
    at makeError (/home/nicojs/stryker/packages/core/node_modules/execa/lib/error.js:59:11)
    at handlePromise (/home/nicojs/stryker/packages/core/node_modules/execa/index.js:114:26)

We're getting the "unused @ts-expect-error" because the strip-comments dependency isn't stripping the comments for some reason. See problem 3 discussed in #2438

We need to find another way to deal with typescript compile errors.