fix: ensure that errorParser always returns something

[mathieudutour]

Description

• The api-runner-node assumes that api-runner-error-parser always returns something. (https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby/src/utils/api-runner-node.js#L381-L411)
• That's not the case if the error is a string (as is the case for gatsby-plugin-manifest)

This makes api-runner-error-parser a bit more robust by returning a default error if we didn't manage to parse it.

I'll fix the gatsby-plugin-manifest in another PR

[blainekasten]

Happy to see this change go through, mind adding a test to confirm its use?

[pieh]

Could we maybe change our handlers and looping over handlers so the
// Match anything with a generic catch-all error handler handler just doesn't have regex test (to trully catch-all) and inside loop see if there is no regex test, just match it? Alternatively remove catch-all handler from handlers array and rely on this newly added catch-all case? To me it seems we have "duplicate" catch-all error handlers where one is not trully catch-all right now in this PR

[pieh]

This is awesome! Thank you!

Additionally on top of fixing non-error throws - it also restores stack trace that was missing recently (err was assigned string so error: err instanceof Error ? err : undefined was always undefined)

tests were added

[pieh]

Published in gatsby@2.19.42