fix: resolve golangci-lint errcheck and staticcheck warnings

- Use _, _ = fmt.Fprintf(...) for diagnostic writes to stderr
- Use defer func() { _ = resp.Body.Close() }() for HTTP response bodies
- Use _ = json.NewEncoder/r.ParseForm in test handlers
- Remove unused newTestClient helper from client_test.go
- Lowercase error string in requireHost() (staticcheck ST1005)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: magifd2

cmd/root.go

@@ -139,7 +139,7 @@ func promptForCredentials() error {
 // requireHost returns an error if no host is configured.
 func requireHost() error {
 	if cfg.Host == "" {
-		return fmt.Errorf("Splunk host is required (--host, SPLUNK_HOST env var, or host in config file)")
+		return fmt.Errorf("splunk host is required (--host, SPLUNK_HOST env var, or host in config file)")
 	}
 	return nil
 }

cmd/run.go

@@ -129,7 +129,7 @@ func readFromTTY() string {
 	if runtime.GOOS != "windows" {
 		tty, err := os.Open("/dev/tty")
 		if err == nil {
-			defer tty.Close()
+			defer func() { _ = tty.Close() }()
 			r = tty
 		}
 	}

internal/client/client.go

@@ -76,14 +76,14 @@ func New(cfg *config.Config, silent bool) (*Client, error) {
 // Logf writes to stderr unless silent.
 func (c *Client) Logf(format string, a ...any) {
 	if !c.silent {
-		fmt.Fprintf(c.stderr, format, a...)
+		_, _ = fmt.Fprintf(c.stderr, format, a...)
 	}
 }
 
 // debugf writes to stderr only when debug is enabled.
 func (c *Client) debugf(format string, a ...any) {
 	if c.cfg.Debug {
-		fmt.Fprintf(c.stderr, "DEBUG: "+format, a...)
+		_, _ = fmt.Fprintf(c.stderr, "DEBUG: "+format, a...)
 	}
 }
 
@@ -177,7 +177,7 @@ func (c *Client) StartSearch(ctx context.Context, spl, earliest, latest string)
 	if err != nil {
 		return "", err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if err := checkStatus(resp, http.StatusCreated); err != nil {
 		return "", err
@@ -212,7 +212,7 @@ func (c *Client) GetJobStatus(ctx context.Context, sid string) (JobStatus, error
 	if err != nil {
 		return JobStatus{}, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if err := checkStatus(resp, http.StatusOK); err != nil {
 		return JobStatus{}, err
@@ -337,7 +337,7 @@ func (c *Client) fetchResultsPage(ctx context.Context, sid string, offset, count
 	if err != nil {
 		return nil, err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if err := checkStatus(resp, http.StatusOK); err != nil {
 		return nil, err
@@ -370,7 +370,7 @@ func (c *Client) CancelSearch(ctx context.Context, sid string) error {
 	if err != nil {
 		return err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)

internal/client/client_test.go

@@ -11,26 +11,6 @@ import (
 	"github.com/nlink-jp/splunk-cli/internal/config"
 )
 
-func newTestClient(t *testing.T, handler http.Handler) *Client {
-	t.Helper()
-	srv := httptest.NewTLSServer(handler)
-	t.Cleanup(srv.Close)
-
-	cfg := &config.Config{
-		Host:     srv.URL,
-		Token:    "testtoken",
-		Insecure: true,
-	}
-	c, err := New(cfg, true)
-	if err != nil {
-		t.Fatalf("New: %v", err)
-	}
-	// Use the test server's TLS client to handle self-signed cert.
-	c.http = srv.Client()
-	// Re-add token setup by wrapping the transport.
-	return c
-}
-
 func TestStartSearch(t *testing.T) {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
@@ -40,7 +20,7 @@ func TestStartSearch(t *testing.T) {
 			t.Errorf("unexpected path: %s", r.URL.Path)
 		}
 		w.WriteHeader(http.StatusCreated)
-		json.NewEncoder(w).Encode(map[string]string{"sid": "test_sid_123"})
+		_ = json.NewEncoder(w).Encode(map[string]string{"sid": "test_sid_123"})
 	})
 
 	srv := httptest.NewServer(handler)
@@ -64,10 +44,10 @@ func TestStartSearch(t *testing.T) {
 func TestStartSearch_PipePrefix(t *testing.T) {
 	var gotSearch string
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		r.ParseForm()
+		_ = r.ParseForm()
 		gotSearch = r.FormValue("search")
 		w.WriteHeader(http.StatusCreated)
-		json.NewEncoder(w).Encode(map[string]string{"sid": "sid1"})
+		_ = json.NewEncoder(w).Encode(map[string]string{"sid": "sid1"})
 	})
 
 	srv := httptest.NewServer(handler)
@@ -77,13 +57,13 @@ func TestStartSearch_PipePrefix(t *testing.T) {
 	c, _ := New(cfg, true)
 
 	// SPL starting with | should NOT get "search " prefix.
-	c.StartSearch(context.Background(), "| stats count", "", "")
+	_, _ = c.StartSearch(context.Background(), "| stats count", "", "")
 	if gotSearch != "| stats count" {
 		t.Errorf("pipe SPL should not get prefix, got: %q", gotSearch)
 	}
 
 	// Normal SPL should get "search " prefix.
-	c.StartSearch(context.Background(), "index=main", "", "")
+	_, _ = c.StartSearch(context.Background(), "index=main", "", "")
 	if gotSearch != "search index=main" {
 		t.Errorf("normal SPL should get prefix, got: %q", gotSearch)
 	}
@@ -92,7 +72,7 @@ func TestStartSearch_PipePrefix(t *testing.T) {
 func TestGetJobStatus(t *testing.T) {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]any{
+		_ = json.NewEncoder(w).Encode(map[string]any{
 			"entry": []map[string]any{
 				{"content": map[string]any{
 					"isDone":        true,
@@ -127,7 +107,7 @@ func TestGetJobStatus(t *testing.T) {
 
 func TestGetJobStatus_NotFound(t *testing.T) {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		json.NewEncoder(w).Encode(map[string]any{"entry": []any{}})
+		_ = json.NewEncoder(w).Encode(map[string]any{"entry": []any{}})
 	})
 
 	srv := httptest.NewServer(handler)
@@ -145,7 +125,7 @@ func TestGetJobStatus_NotFound(t *testing.T) {
 func TestGetJobStatus_APIError(t *testing.T) {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusUnauthorized)
-		w.Write([]byte("Unauthorized"))
+		_, _ = w.Write([]byte("Unauthorized"))
 	})
 
 	srv := httptest.NewServer(handler)
@@ -168,7 +148,7 @@ func TestCancelSearch(t *testing.T) {
 		if !strings.Contains(r.URL.Path, "control") {
 			t.Errorf("unexpected path: %s", r.URL.Path)
 		}
-		r.ParseForm()
+		_ = r.ParseForm()
 		if r.FormValue("action") != "cancel" {
 			t.Errorf("expected action=cancel, got %q", r.FormValue("action"))
 		}

internal/config/config.go

@@ -121,7 +121,7 @@ func ApplyEnvVars(cfg *Config) {
 
 func checkPermissions(path string, info os.FileInfo) {
 	if info.Mode().Perm()&0077 != 0 {
-		fmt.Fprintf(Stderr,
+		_, _ = fmt.Fprintf(Stderr,
 			"Warning: config file %s has permissions %#o; expected 0600.\n"+
 				"  The file may contain credentials. Run: chmod 600 %s\n",
 			path, info.Mode().Perm(), path,