wp-env: no longer show error message twice

[noahtallen]

I noticed during some testing today that wp-env would show error messages twice. This PR attempts to only display the error message once. @noisysocks / @epiqueras I may be missing the context for why we needed to check for error instanceof env.ValidationError and then display the error twice, so if you have thoughts I'm all ears. :) Perhaps there are some cases where multiline error output wouldn't be shown by spinner.fail?

Screenshots

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[epiqueras]

The spinner is for single line errors. The log should be reserved for standard error output. In other words, always do the spinner thing and only log if the out property is present.

[noahtallen]

Makes sense! Done :)

[epiqueras]

Looks good to me but I’ll let @noisysocks approve as he was the last one to touch this.

[noahtallen]

Rebased. cc @noisysocks again just in case. ;)

[noisysocks]

I think we still want to print error.err to STDERR?

This part of the code confused me too. There's many types of error and so writing one handler for them all involves considering several execution paths 😅

I'm thinking let's give up and just explicitly handle each of the different error types instead:

( error ) => {
	if ( error instanceof env.ValidationError ) {
		// Error is a validation error. That means the user did something wrong.
		spinner.fail( error.message );
		process.exit( 1 );
	} else if (
		'exitCode' in error &&
		'err' in error &&
		'out' in error
	) {
		// Error is a docker-compose error. That means something docker-related failed.
		// https://github.com/PDMLab/docker-compose/blob/master/src/index.ts
		spinner.fail( 'Error while running docker-compose command.' );
		if ( error.out ) {
			process.stdout.write( error.out );
		}
		if ( error.err ) {
			process.stderr.write( error.err );
		}
		process.exit( error.exitCode );
	} else {
		// Error is an unknown error. That means there was a bug in our code.
		spinner.fail( error.message );
		// Disable reason: Using console.error() means we get a stack trace.
		// eslint-disable-next-line no-console
		console.error( error );
		process.exit( 1 );
	}
}

[noahtallen]

@noisysocks That makes a lot of sense, done! ✅

Updated with the new code, the same error looks like this, which is definitely an improvement.