refactor(tests): improve error handling and defer usage

- Add error checking for os.Setenv and io operations in test files
- Use anonymous functions in defer to ignore errors from os.Remove, os.Setenv, etc.
- Minor formatting and consistency fixes in tests and client code

cmd/chat_test.go

@@ -9,10 +9,12 @@ import (
 func TestGetChatHistoryFile(t *testing.T) {
 	// Save original HOME
 	oldHome := os.Getenv("HOME")
-	defer os.Setenv("HOME", oldHome)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	tmpDir := t.TempDir()
-	os.Setenv("HOME", tmpDir)
+	if err := os.Setenv("HOME", tmpDir); err != nil {
+		t.Fatal(err)
+	}
 
 	histFile := getChatHistoryFile()
 	expected := filepath.Join(tmpDir, ".config", "grokkit", "chat_history.json")
@@ -22,11 +24,18 @@ func TestGetChatHistoryFile(t *testing.T) {
 	}
 }
 
+func setHomeForTest(t *testing.T, dir string) {
+	t.Helper()
+	if err := os.Setenv("HOME", dir); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestLoadChatHistory_NoFile(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHomeForTest(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	history := loadChatHistory()
 	if history != nil {
@@ -37,8 +46,8 @@ func TestLoadChatHistory_NoFile(t *testing.T) {
 func TestSaveAndLoadChatHistory(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHomeForTest(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	// Create test messages
 	messages := []map[string]string{
@@ -77,8 +86,8 @@ func TestSaveAndLoadChatHistory(t *testing.T) {
 func TestLoadChatHistory_InvalidJSON(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHomeForTest(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	// Create invalid JSON file
 	histDir := filepath.Join(tmpDir, ".config", "grokkit")

cmd/docs_test.go

@@ -7,9 +7,9 @@ import (
 
 func TestBuildDocsMessages(t *testing.T) {
 	tests := []struct {
-		language    string
-		code        string
-		styleCheck  string
+		language   string
+		code       string
+		styleCheck string
 	}{
 		{language: "Go", code: "package main\nfunc Foo() {}", styleCheck: "godoc"},
 		{language: "Python", code: "def foo():\n    pass", styleCheck: "PEP 257"},

cmd/edit_test.go

@@ -14,7 +14,7 @@ func TestEditCommand(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer os.Remove(tmpfile.Name())
+	defer func() { _ = os.Remove(tmpfile.Name()) }()
 
 	original := []byte("package main\n\nfunc hello() {}\n")
 	if err := os.WriteFile(tmpfile.Name(), original, 0644); err != nil {

cmd/run_test.go

@@ -205,8 +205,12 @@ func TestRunCommit(t *testing.T) {
 		r, w, _ := os.Pipe()
 		origStdin := os.Stdin
 		os.Stdin = r
-		w.WriteString("n\n")
-		w.Close()
+		if _, err := w.WriteString("n\n"); err != nil {
+			t.Fatal(err)
+		}
+		if err := w.Close(); err != nil {
+			t.Fatal(err)
+		}
 		defer func() { os.Stdin = origStdin }()
 
 		runCommit(testCmd(), nil)
@@ -357,8 +361,10 @@ func TestProcessDocsFileUnsupportedLanguage(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	f.Close()
-	defer os.Remove(f.Name())
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = os.Remove(f.Name()) }()
 
 	mock := &mockStreamer{}
 	processDocsFile(mock, "grok-4", f.Name())
@@ -376,9 +382,11 @@ func TestProcessDocsFilePreviewAndCancel(t *testing.T) {
 	if _, err := f.WriteString("package main\n\nfunc Foo() {}\n"); err != nil {
 		t.Fatal(err)
 	}
-	f.Close()
-	defer os.Remove(f.Name())
-	defer os.Remove(f.Name() + ".bak")
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = os.Remove(f.Name()) }()
+	defer func() { _ = os.Remove(f.Name() + ".bak") }()
 
 	mock := &mockStreamer{response: "package main\n\n// Foo does nothing.\nfunc Foo() {}\n"}
 
@@ -390,8 +398,12 @@ func TestProcessDocsFilePreviewAndCancel(t *testing.T) {
 	r, w, _ := os.Pipe()
 	origStdin := os.Stdin
 	os.Stdin = r
-	w.WriteString("n\n")
-	w.Close()
+	if _, err := w.WriteString("n\n"); err != nil {
+		t.Fatal(err)
+	}
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
 	defer func() { os.Stdin = origStdin }()
 
 	processDocsFile(mock, "grok-4", f.Name())
@@ -410,9 +422,11 @@ func TestProcessDocsFileAutoApply(t *testing.T) {
 	if _, err := f.WriteString(original); err != nil {
 		t.Fatal(err)
 	}
-	f.Close()
-	defer os.Remove(f.Name())
-	defer os.Remove(f.Name() + ".bak")
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = os.Remove(f.Name()) }()
+	defer func() { _ = os.Remove(f.Name() + ".bak") }()
 
 	// CleanCodeResponse will trim the trailing newline from the AI response.
 	aiResponse := "package main\n\n// Bar does nothing.\nfunc Bar() {}\n"

internal/grok/client.go

@@ -106,7 +106,7 @@ func (c *Client) streamInternal(messages []map[string]string, model string, temp
 		color.Red("Request failed: %v", err)
 		os.Exit(1)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	logger.Debug("API response received",
 		"status", resp.Status,
@@ -173,4 +173,4 @@ func CleanCodeResponse(text string) string {
 	text = strings.TrimSpace(text)
 
 	return text
-}
+}

internal/grok/client_test.go

@@ -55,9 +55,9 @@ func sseServer(chunks []string) *httptest.Server {
 	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")
 		for _, c := range chunks {
-			fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":%q}}]}\n\n", c)
+			_, _ = fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":%q}}]}\n\n", c)
 		}
-		fmt.Fprintf(w, "data: [DONE]\n\n")
+		_, _ = fmt.Fprintf(w, "data: [DONE]\n\n")
 	}))
 }
 
@@ -98,10 +98,10 @@ func TestStreamDoneSignal(t *testing.T) {
 	// Verifies that [DONE] stops processing and non-content chunks are skipped
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")
-		fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":\"ok\"}}]}\n\n")
-		fmt.Fprintf(w, "data: [DONE]\n\n")
+		_, _ = fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":\"ok\"}}]}\n\n")
+		_, _ = fmt.Fprintf(w, "data: [DONE]\n\n")
 		// This line should never be processed
-		fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":\"extra\"}}]}\n\n")
+		_, _ = fmt.Fprintf(w, "data: {\"choices\":[{\"delta\":{\"content\":\"extra\"}}]}\n\n")
 	}))
 	defer srv.Close()
 
@@ -115,7 +115,7 @@ func TestStreamDoneSignal(t *testing.T) {
 func TestStreamEmptyResponse(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "text/event-stream")
-		fmt.Fprintf(w, "data: [DONE]\n\n")
+		_, _ = fmt.Fprintf(w, "data: [DONE]\n\n")
 	}))
 	defer srv.Close()
 
@@ -131,13 +131,15 @@ func TestNewClient(t *testing.T) {
 	oldKey := os.Getenv("XAI_API_KEY")
 	defer func() {
 		if oldKey != "" {
-			os.Setenv("XAI_API_KEY", oldKey)
+			_ = os.Setenv("XAI_API_KEY", oldKey)
 		} else {
-			os.Unsetenv("XAI_API_KEY")
+			_ = os.Unsetenv("XAI_API_KEY")
 		}
 	}()
 
-	os.Setenv("XAI_API_KEY", "test-key")
+	if err := os.Setenv("XAI_API_KEY", "test-key"); err != nil {
+		t.Fatal(err)
+	}
 	client := NewClient()
 
 	if client.APIKey != "test-key" {

internal/linter/linter_test.go

@@ -321,7 +321,7 @@ func TestLanguageStructure(t *testing.T) {
 func contains(s, substr string) bool {
 	return len(s) >= len(substr) && (s == substr || len(s) > len(substr) &&
 		(s[:len(substr)] == substr || s[len(s)-len(substr):] == substr ||
-		containsMiddle(s, substr)))
+			containsMiddle(s, substr)))
 }
 
 func containsMiddle(s, substr string) bool {

internal/logger/logger_test.go

@@ -7,12 +7,18 @@ import (
 	"testing"
 )
 
+func setHome(t *testing.T, dir string) {
+	t.Helper()
+	if err := os.Setenv("HOME", dir); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestInit(t *testing.T) {
-	// Create temp directory
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHome(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	tests := []struct {
 		name     string
@@ -32,7 +38,6 @@ func TestInit(t *testing.T) {
 				t.Errorf("Init(%q) unexpected error: %v", tt.logLevel, err)
 			}
 
-			// Check log file was created
 			logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
 			if _, err := os.Stat(logFile); os.IsNotExist(err) {
 				t.Errorf("Log file not created at %s", logFile)
@@ -44,20 +49,18 @@ func TestInit(t *testing.T) {
 func TestLogging(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHome(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	if err := Init("debug"); err != nil {
 		t.Fatalf("Init() failed: %v", err)
 	}
 
-	// Test all log levels with structured fields
 	Debug("test debug message", "key", "value")
 	Info("test info message", "count", 42)
 	Warn("test warn message", "enabled", true)
 	Error("test error message", "error", "something went wrong")
 
-	// Verify log file has content
 	logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
 	content, err := os.ReadFile(logFile)
 	if err != nil {
@@ -67,7 +70,6 @@ func TestLogging(t *testing.T) {
 		t.Errorf("Log file is empty")
 	}
 
-	// Check for JSON structure (slog uses JSON handler)
 	contentStr := string(content)
 	if !strings.Contains(contentStr, `"level"`) {
 		t.Errorf("Log content doesn't contain JSON level field")
@@ -80,20 +82,16 @@ func TestLogging(t *testing.T) {
 func TestSetLevel(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHome(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	if err := Init("info"); err != nil {
 		t.Fatalf("Init() failed: %v", err)
 	}
 
-	// Change level to debug
 	SetLevel("debug")
-
-	// Log at debug level
 	Debug("debug after level change", "test", true)
 
-	// Verify log file has the debug message
 	logFile := filepath.Join(tmpDir, ".config", "grokkit", "grokkit.log")
 	content, err := os.ReadFile(logFile)
 	if err != nil {
@@ -108,14 +106,13 @@ func TestSetLevel(t *testing.T) {
 func TestWith(t *testing.T) {
 	tmpDir := t.TempDir()
 	oldHome := os.Getenv("HOME")
-	os.Setenv("HOME", tmpDir)
-	defer os.Setenv("HOME", oldHome)
+	setHome(t, tmpDir)
+	defer func() { _ = os.Setenv("HOME", oldHome) }()
 
 	if err := Init("info"); err != nil {
 		t.Fatalf("Init() failed: %v", err)
 	}
 
-	// Create logger with context
 	contextLogger := With("request_id", "123", "user", "testuser")
 	if contextLogger == nil {
 		t.Errorf("With() returned nil logger")