feat(config): improve karma.config.parseConfig error handling

[npetruzzelli]

This PR add the ability of Public API users of parseConfig to opt-in to throwing errors when a critical failure is encountered.

The current behavior is to exit the process immediately, which denies the API consumer the ability to log or respond to the error at their application's level.

Related Issue: #3631

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[npetruzzelli]

Before I clean up comments and attempt to write tests for the new code, I was hoping to get feedback on this first attempt.

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[npetruzzelli]

@googlebot I signed it!

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[npetruzzelli]

I wasn't sure if you intended for fail to be used outside of parseConfig. If that was the case, the signature would need only a minor change.

function fail (logArgs, failOptions) {
    const _logArgs = Array.isArray(logArgs) ? logArgs : [logArgs]
    log.error(..._logArgs )
    if (failOptions && failOptions.throwErrors === true) {
    // ...
}
// in `parseConfig`
fail (message, parseOptions)
fail ([message, e], parseOptions)

// -- OR --

function fail (logArgs, throwErrors) {
    const _logArgs = Array.isArray(logArgs) ? logArgs : [logArgs]
    log.error(..._logArgs )
    if (throwErrors === true) {
    // ...
}

// -- OR --

function fail (throwErrors, ...logArgs) {
    log.error(...logArgs )
    if (throwErrors === true) {
    // ...
}

[devoto13]

Please also update the usage of parseConfig in Karma's source code, so it does not rely on the deprecated behavior (last point in #3631 (comment)).

And add a unit test for parseConfig function with throwErrors: true.

Otherwise, it looks good 👍
Thanks!

[devoto13]

I wasn't sure if you intended for fail to be used outside of parseConfig. If that was the case, the signature would need only a minor change.

Good to know! Let's keep it simple here and we can adjust the signature in the next PR (if/when necessary).

[karmarunnerbot]

✅ Build karma 495 completed (commit 078db6fc9f by @npetruzzelli)