fix(telemetry): honor --config flag in enable/disable save path

cmd/mcpproxy/telemetry_cmd.go

@@ -192,7 +192,7 @@ func runTelemetryEnable(cmd *cobra.Command, _ []string) error {
 	enabled := true
 	cfg.Telemetry.Enabled = &enabled
 
-	configPath := config.GetConfigPath(cfg.DataDir)
+	configPath := telemetryConfigSavePath(cfg)
 	if err := config.SaveConfig(cfg, configPath); err != nil {
 		return fmt.Errorf("failed to save config: %w", err)
 	}
@@ -216,7 +216,7 @@ func runTelemetryDisable(cmd *cobra.Command, _ []string) error {
 	disabled := false
 	cfg.Telemetry.Enabled = &disabled
 
-	configPath := config.GetConfigPath(cfg.DataDir)
+	configPath := telemetryConfigSavePath(cfg)
 	if err := config.SaveConfig(cfg, configPath); err != nil {
 		return fmt.Errorf("failed to save config: %w", err)
 	}
@@ -245,3 +245,15 @@ func loadTelemetryConfig() (*config.Config, error) {
 	}
 	return cfg, nil
 }
+
+// telemetryConfigSavePath returns the config path that telemetry subcommands
+// should write to. It mirrors loadTelemetryConfig: when the user passed
+// --config, that exact file is used; otherwise the default derived from
+// DataDir. This fixes a bug where enable/disable always wrote to the default
+// location regardless of --config (pre-existing from PR #345 / Spec 036).
+func telemetryConfigSavePath(cfg *config.Config) string {
+	if configFile != "" {
+		return configFile
+	}
+	return config.GetConfigPath(cfg.DataDir)
+}

cmd/mcpproxy/telemetry_cmd_test.go

@@ -0,0 +1,161 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/smart-mcp-proxy/mcpproxy-go/internal/config"
+)
+
+// writeMinimalConfig writes a small valid config JSON to path.
+func writeMinimalConfig(t *testing.T, path string, dataDir string) {
+	t.Helper()
+	cfg := map[string]interface{}{
+		"listen":   "127.0.0.1:0",
+		"data_dir": dataDir,
+		"telemetry": map[string]interface{}{
+			"enabled": true,
+		},
+	}
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal config: %v", err)
+	}
+	if err := os.WriteFile(path, data, 0600); err != nil {
+		t.Fatalf("write config: %v", err)
+	}
+}
+
+func readTelemetryEnabled(t *testing.T, path string) *bool {
+	t.Helper()
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read %s: %v", path, err)
+	}
+	var out struct {
+		Telemetry *struct {
+			Enabled *bool `json:"enabled"`
+		} `json:"telemetry"`
+	}
+	if err := json.Unmarshal(raw, &out); err != nil {
+		t.Fatalf("unmarshal %s: %v", path, err)
+	}
+	if out.Telemetry == nil {
+		return nil
+	}
+	return out.Telemetry.Enabled
+}
+
+// sandboxHome redirects HOME (and XDG-style vars) to a tempdir so that
+// fallback paths to "~/.mcpproxy/mcp_config.json" land in a sandbox instead
+// of clobbering the developer's real config.
+func sandboxHome(t *testing.T) string {
+	t.Helper()
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, ".config"))
+	t.Setenv("XDG_DATA_HOME", filepath.Join(home, ".local", "share"))
+	// On macOS config.Load() might consult USERPROFILE on some paths; harmless on unix.
+	t.Setenv("USERPROFILE", home)
+	return home
+}
+
+// TestRunTelemetryDisable_HonorsConfigFlag is the regression test for the bug
+// where `mcpproxy telemetry disable --config /tmp/custom.json` wrote to
+// ~/.mcpproxy/mcp_config.json instead of the custom path.
+func TestRunTelemetryDisable_HonorsConfigFlag(t *testing.T) {
+	home := sandboxHome(t)
+
+	// Target config file at an explicit path unrelated to the fake home.
+	tmpDir := t.TempDir()
+	customPath := filepath.Join(tmpDir, "custom_mcp_config.json")
+	dataDir := filepath.Join(tmpDir, "data")
+	writeMinimalConfig(t, customPath, dataDir)
+
+	// Simulate `--config customPath` by setting the package-level flag var.
+	prev := configFile
+	configFile = customPath
+	t.Cleanup(func() { configFile = prev })
+
+	if err := runTelemetryDisable(nil, nil); err != nil {
+		t.Fatalf("runTelemetryDisable: %v", err)
+	}
+
+	// The custom config file must now have telemetry.enabled == false.
+	enabled := readTelemetryEnabled(t, customPath)
+	if enabled == nil {
+		t.Fatal("custom config: telemetry.enabled missing after disable")
+	}
+	if *enabled {
+		t.Errorf("custom config: telemetry.enabled = true, want false")
+	}
+
+	// The sandboxed default path must NOT have been created or modified.
+	defaultPath := filepath.Join(home, ".mcpproxy", "mcp_config.json")
+	if _, err := os.Stat(defaultPath); !os.IsNotExist(err) {
+		t.Errorf("default config path should not exist in sandbox, got err=%v", err)
+	}
+}
+
+// TestRunTelemetryEnable_HonorsConfigFlag mirrors the disable test for enable.
+func TestRunTelemetryEnable_HonorsConfigFlag(t *testing.T) {
+	sandboxHome(t)
+
+	tmpDir := t.TempDir()
+	customPath := filepath.Join(tmpDir, "custom_mcp_config.json")
+	dataDir := filepath.Join(tmpDir, "data")
+
+	// Start with telemetry disabled so enable is observable.
+	cfg := map[string]interface{}{
+		"listen":   "127.0.0.1:0",
+		"data_dir": dataDir,
+		"telemetry": map[string]interface{}{
+			"enabled": false,
+		},
+	}
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	if err := os.WriteFile(customPath, data, 0600); err != nil {
+		t.Fatalf("write: %v", err)
+	}
+
+	prev := configFile
+	configFile = customPath
+	t.Cleanup(func() { configFile = prev })
+
+	if err := runTelemetryEnable(nil, nil); err != nil {
+		t.Fatalf("runTelemetryEnable: %v", err)
+	}
+
+	enabled := readTelemetryEnabled(t, customPath)
+	if enabled == nil {
+		t.Fatal("custom config: telemetry.enabled missing after enable")
+	}
+	if !*enabled {
+		t.Errorf("custom config: telemetry.enabled = false, want true")
+	}
+}
+
+// TestTelemetryConfigSavePath_PrefersConfigFileFlag is a small unit test for
+// the helper itself: when configFile is set, it wins over the DataDir-derived
+// default; when unset, it falls back to config.GetConfigPath(DataDir).
+func TestTelemetryConfigSavePath_PrefersConfigFileFlag(t *testing.T) {
+	cfg := &config.Config{DataDir: "/tmp/fake-data-dir"}
+
+	prev := configFile
+	t.Cleanup(func() { configFile = prev })
+
+	configFile = ""
+	if got := telemetryConfigSavePath(cfg); got != config.GetConfigPath(cfg.DataDir) {
+		t.Errorf("with empty configFile: got %q, want default %q", got, config.GetConfigPath(cfg.DataDir))
+	}
+
+	configFile = "/elsewhere/custom.json"
+	if got := telemetryConfigSavePath(cfg); got != "/elsewhere/custom.json" {
+		t.Errorf("with configFile set: got %q, want %q", got, "/elsewhere/custom.json")
+	}
+}