[test-improver] Improve tests for logger/FileLogger

[github-actions]

Test Improvements: file_logger_test.go

File Analyzed

• Test File: internal/logger/file_logger_test.go
• Package: internal/logger
• Lines of Code: 246 → 338 (+92 lines)

Improvements Made

1. Better Testify Assertions

Replaced all non-idiomatic assertion patterns with proper testify equivalents:

• ✅ Replaced assert.True(t, strings.Contains(s, sub)) → assert.Contains(t, s, sub) across 6 call sites (better error messages showing actual vs. expected)
• ✅ Replaced manual if !strings.Contains + t.Errorf loops → assert.Contains (cleaner, continues on failure per testify semantics)
• ✅ Replaced if len(lines) < 4 { t.Errorf(...) } → require.GreaterOrEqual(t, len(lines), 4, ...)
• ✅ Replaced if len(lines) != 100 { t.Errorf(...) } → assert.Len(t, lines, 100, ...)
• ✅ Improved TestInitFileLogger to use require.NoError for os.Stat checks instead of the os.IsNotExist idiom
• ✅ Cleaned up TestFileLoggerFallback to use require.NotNil for the logger itself

2. Increased Coverage

Added four new test functions that cover previously untested code paths:

• ✅ TestFileLogger_GetWriter (3 subtests): Covers the GetWriter() method on FileLogger which had zero test coverage. Tests the real-logger path (returns *os.File), the fallback path (returns os.Stdout), and the io.Writer interface contract.

• ✅ TestFileLogger_ReinitWithoutClose: Exercises the initGlobalLogger branch in global_helpers.go where *current != nil — i.e., when InitFileLogger is called while a logger is already active. Verifies the old logger is properly closed and the new one takes over.

• ✅ TestFileLogger_LogAfterClose: Exercises the nil-logger guard in withGlobalLogger (also global_helpers.go). Verifies that calling LogInfo/LogWarn/LogError/LogDebug after CloseGlobalLogger silently drops messages without panicking.

• ✅ TestFileLogger_CloseIdempotent: Exercises the nil check in closeGlobalLogger. Verifies that calling CloseGlobalLogger three times in a row (after the logger is closed) returns nil errors each time.

Coverage improvement: The four new tests add coverage to GetWriter() (0% → 100%), and to three previously uncovered branches in global_helpers.go (initGlobalLogger existing-logger path, withGlobalLogger nil path, closeGlobalLogger nil path).

3. Cleaner & More Stable Tests

• ✅ Comments trimmed to only where they add clarity (per project style)
• ✅ Consistent use of assert vs require (critical setup uses require, non-fatal checks use assert)
• ✅ Subtests in TestFileLogger_GetWriter properly isolate test state with defer CloseGlobalLogger()

Why These Changes?

file_logger_test.go was selected because it had the most concentrated use of non-idiomatic assert.True(strings.Contains(...)) patterns in a single file, and because the corresponding implementation (GetWriter(), and the generic global_helpers.go functions) had concrete untested code paths. The global_helpers.go file provides the nil-check guards and re-init logic used by all five logger types, so adding coverage there benefits the entire logger subsystem.

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Generated by Test Improver Workflow
Focuses on better patterns, increased coverage, and more stable tests

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[Copilot]

Pull request overview

This PR improves the internal/logger test suite for FileLogger by refactoring assertions to idiomatic testify usage and adding new tests to cover previously untested global-logger helper paths (GetWriter, re-init, post-close logging, idempotent close).

Changes:

• Refactors existing tests to use assert.Contains, assert.Len, and require.* for clearer failures and better control flow.
• Adds new tests for FileLogger.GetWriter(), re-initialization without explicit close, logging after close, and idempotent close.
• Tightens several log-content checks (category presence, line count expectations).

Comments suppressed due to low confidence (1)

internal/logger/file_logger_test.go:240

• The fallback-path subtest relies on /root/nonexistent/directory and may Skip if the process can write to /root, which reduces determinism and can leave artifacts on the host. Consider using a temp directory with permissions removed (chmod) to guarantee the fallback path is exercised in all environments.

	t.Run("fallback logger returns stdout", func(t *testing.T) {
		err := InitFileLogger("/root/nonexistent/directory", "test.log")
		require.NoError(t, err)
		defer CloseGlobalLogger()

		globalLoggerMu.RLock()
		logger := globalFileLogger
		globalLoggerMu.RUnlock()

		require.NotNil(t, logger)
		if logger.useFallback {
			w := logger.GetWriter()
			assert.Equal(t, os.Stdout, w, "Fallback logger GetWriter should return os.Stdout")
		} else {
			t.Skip("System has permissions to write to /root; cannot test fallback path")
		}

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[Copilot]

In the "real logger returns file writer" subtest, asserting that GetWriter() returns *os.File doesn’t actually distinguish the real-file path from fallback, because os.Stdout is also a *os.File. This test could pass even if initialization silently fell back to stdout. Consider additionally asserting logger.useFallback == false and/or that the returned writer is the same as logger.logFile (and not os.Stdout).

Suggested change

	w := logger.GetWriter()
	require.NotNil(t, w, "GetWriter should return non-nil writer")
	_, isFile := w.(*os.File)
	assert.True(t, isFile, "GetWriter should return *os.File for real logger")
	assert.False(t, logger.useFallback, "real logger should not be using fallback")
	w := logger.GetWriter()
	require.NotNil(t, w, "GetWriter should return non-nil writer")
	assert.Same(t, logger.logFile, w, "GetWriter should return the underlying log file for real logger")
	assert.NotEqual(t, os.Stdout, w, "real logger writer should not be os.Stdout")

[Copilot]

These tests use a hard-coded /root/nonexistent/directory to try to force fallback. This makes behavior environment-dependent (e.g., running tests as root can create/write there, and other platforms may not have /root), and it can also leave artifacts outside the temp test directory. A more deterministic approach is to create a temp dir and chmod it to non-writable (or create a non-writable parent) to reliably trigger the fallback without touching system paths.

This issue also appears on line 225 of the same file.

[Copilot]

The "GetWriter implements io.Writer interface" subtest is effectively a no-op because GetWriter() already has return type io.Writer, so the assignment will always compile and doesn’t validate behavior. If the intent is to verify the returned writer is usable, consider asserting it is non-nil and performing a small Write() (and optionally checking the log file contents).