Improve test quality: scripts/lint_error_messages_test.go

[Copilot]

scripts/lint_error_messages_test.go had zero testify usage and incomplete coverage — bare t.Errorf patterns, an unused wantContain field, only 3 of 7 regex patterns tested, and no tests for analyzeFile.

Changes

• Testify adoption: Replace all if x != y { t.Errorf(...) } patterns with assert.Equal, assert.Nil/assert.NotNil, assert.NotEmpty, assert.Contains; use require.NoError for setup steps in TestAnalyzeFile
• TestCheckErrorQuality: Simplified pass/fail branches to single assert.Nil/assert.NotNil with descriptive messages
• TestSuggestImprovement: wantContain is now actually asserted via assert.Contains instead of being ignored
• TestPatternMatching: Expanded from 4 cases (3 patterns) to 22 cases covering all 7 compiled regex patterns — hasExample, hasExpected, isValidationError, isFormatError, isTypeError, isEnumError, isWrappedError, hasDocLink — each with both a match and a non-match case
• TestAnalyzeFile (new): 5 subtests exercising the core AST-walking function across compliant, non-compliant, mixed, empty, and unparseable files

[Copilot]

Pull request overview

Improves the quality and coverage of scripts/lint_error_messages_test.go by adopting testify assertions and adding missing tests for regex pattern matching and analyzeFile.

Changes:

• Replaced manual t.Errorf checks with testify/assert + testify/require for clearer, more consistent test failures.
• Expanded TestPatternMatching to cover all compiled regexes with both match and non-match cases.
• Added TestAnalyzeFile to exercise AST-walking behavior across compliant, non-compliant, mixed, empty, and unparseable files; removed now-unused indirect deps via tidy.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
scripts/lint_error_messages_test.go	Switch to testify, expand regex coverage, and add new analyzeFile tests using temp Go files.
go.mod	Removes an unused indirect dependency (github.com/sahilm/fuzzy).
go.sum	Drops stale checksums consistent with dependency cleanup/tidy.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

In TestPatternMatching, the switch tt.pattern has no default case. If a new/typo pattern string is added with want: false, the test will silently pass because result stays at the zero value (false). Consider adding a default branch that fails the test (e.g., via t.Fatalf) when an unknown pattern key is encountered, so incorrect test cases don’t get masked.

Suggested change

	result = hasDocLink.MatchString(tt.message)
	result = hasDocLink.MatchString(tt.message)
	default:
	t.Fatalf("unknown pattern %q in test %q", tt.pattern, tt.name)