assert: fix misformatted error message

[Trott]

Before: Missing expected exception..

Afer: Missing expected exception.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

assert

[Trott]

Technically semver-major because of the idiosyncratic way we have to be
super-careful with error messages. If anyone thinks it violates the
Locked API due to that, I won't argue the point. (Paging @ChALkeR!)

My thinking is that this doesn't violate the Locked API because it's a bug fix, even if we have a policy (at least at this time) to treat this particular type of bug fix like it's semver major.

But a "sorry, semver major is semver major, deal with it" approach also makes sense. (In which case, I might see if there's a general sentiment to unlock the API but that's another conversation.)

[gibfahn]

LGTM, and definitely seems related to #11200.

[lpinca]

shouldn't this end with . when message is truthy?

(message ? ` ${message}.` : '');

[Trott]

Yes, unless message is expected to already end with ., so ¯\(ツ)/¯. And there should also be a : rather than . after expected if message is truthy.

Thinking about this some more and looking at the uses, I wonder if the thing to do is get rid of all the logic for appending . in the first place. Nothing else appends .. And this mostly only seems to do it wrong!

Current master results in messages like this:

AssertionError: Missing expected exception..
AssertionError: Missing expected exception. foo bar baz

wat?

Compare to assert.strictEqual() which does not append .:

AssertionError: 'a' === 'b'
AssertionError: foo bar baz

[Trott]

@lpinca OK, I just pushed some improvements based on your comment. PTAL

[lpinca]

@Trott

Thinking about this some more and looking at the uses, I wonder if the thing to do is get rid of all the logic for appending . in the first place.

This also makes sense imo, I think most error messages don't use . at all.

[Trott]

I'm going to apply the blocked label to this until #11304 lands or there's some other satisfactory resolution for #11200.

[jasnell]

CI: https://ci.nodejs.org/job/node-test-pull-request/6355/

[Trott]

assert is now Stable rather than Locked so this is un-blocked.

[Trott]

Landed in 0af4183