refactor unit tests to follow Go guidelines

[pellared]

Per #38 (review)

Follow:

• https://go.dev/wiki/CodeReviewComments#useful-test-failures

Note that the order here is actual != expected, and the message uses that order too. Some test frameworks encourage writing these backwards: 0 != x, “expected 0, got x”, and so on. Go does not.

• https://go.dev/wiki/TestComments#table-driven-tests-vs-multiple-test-functions

When some test cases need to be checked using different logic from other test cases, it is more appropriate to write multiple test functions. The logic of your test code can get difficult to understand when every entry in a table has to be subjected to multiple kinds of conditional logic to do the right kind of output check for the right kind of input.

[ywwg]

thanks for these! I very rarely see tests done in pure Go, most of our stuff is testified

[Copilot]

Pull Request Overview

This PR refactors existing unit tests to follow Go’s testing style guidelines for clearer test failures and simpler test logic separation.

• normalize_label_test.go: Converted to table-driven tests and split out UTF-8 allowed cases into a separate test function.
• metric_namer_test.go: Renamed expected* fields to want* and updated error messages to use the “got, want” ordering.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
normalize_label_test.go	Refactored TestNormalizeLabel into table-driven form and added a separate UTF-8 allowed test.
metric_namer_test.go	Changed expectedMetricName/expectedUnitName to wantMetricName/wantUnitName and updated error calls.

Comments suppressed due to low confidence (1)

normalize_label_test.go:40

• [nitpick] Using tt.label as the subtest name will produce an empty name for the case where label == "". Consider deriving a non-empty name (e.g. include the index or a descriptive string) so the subtest is easier to identify.

t.Run(tt.label, func(t *testing.T) {

[pellared]

Anyone willing to merge this PR? 😁