Ensure HTTPError always has a defined message

[kumar303]

Fixes #248

This ensures HTTPError will always have a defined message in various situations.

[yunyu]

This would also help with Sentry error reporting.

[sholladay]

I like the implementation but for the tests, I would prefer to use more realistic objects and patterns that align better with the other existing tests. For example, use an actual test server that responds without status text. Or instead of http.ServerResponse, return a WHATWG Response inside of a hook.

[kumar303]

Thanks for the quick review!

I like the implementation but for the tests, I would prefer to use more realistic objects and patterns that align better with the other existing tests. For example, use an actual test server that responds without status text.

Yeah, I struggled with this a bit. I couldn't see an easy way to make a response with an undefined statusText using the test server (it doesn't provide low enough access to the response).

Or instead of http.ServerResponse, return a WHATWG Response inside of a hook.

Ah, yes, a WHATWG Response would be more realistic. I'll try that.

[kumar303]

@sholladay I switched to a proper fetch Response. Let me know how it looks.

[kumar303]

@sholladay this supports status codes of 0 now.

[sholladay]

These can be set in the init argument for the Response constructor. Should be eas easy as...

const error = new ky.HTTPError(new Response(null, { status: 200, statusText: 'Foo bar' }));

[kumar303]

It doesn't work because these values need to be set to undefined and from looking at the node-fetch source, they are using old school truthy checks to tell if these values are set (thus, they can never be set to undefined).

I realize it makes the code look a bit odd -- that's why I added a comment explaining it.

[kumar303]

@sholladay let me know if my response makes sense. Thanks.

[sholladay]

LGTM.

Might be nice, though, to add parentheses around the OR condition (... || ...) to make it clear that it has higher precedence than the ternary.