Fix lint errors

Follow up #40

command/test_helper.go

@@ -46,10 +46,14 @@ func setupTestAcc(t *testing.T, providerName string, providerVersion string) {
 	if err != nil {
 		t.Fatalf("failed to get current dir: %s", err)
 	}
-	os.Chdir(workDir) // nolint: errcheck
+	if err := os.Chdir(workDir); err != nil {
+		t.Fatalf("failed to change dir to %s on setup: %s", workDir, err)
+	}
 
 	t.Cleanup(func() {
-		os.Chdir(oldDir) // nolint: errcheck
+		if err := os.Chdir(oldDir); err != nil {
+			t.Fatalf("failed to change dir to %s on cleanup: %s", oldDir, err)
+		}
 		os.RemoveAll(workDir)
 	})
 
@@ -73,7 +77,7 @@ func setupTestWorkDir(source string) (string, error) {
 		return "", fmt.Errorf("failed to create work dir: %s", err)
 	}
 
-	if err := os.WriteFile(filepath.Join(workDir, "main.tf"), []byte(source), 0644); err != nil { // nolint: gosec
+	if err := os.WriteFile(filepath.Join(workDir, "main.tf"), []byte(source), 0600); err != nil {
 		os.RemoveAll(workDir)
 		return "", fmt.Errorf("failed to create main.tf: %s", err)
 	}

main.go

@@ -114,7 +114,9 @@ func copyOutput(r io.Reader, doneCh chan<- struct{}) {
 	wg.Add(1)
 	go func() {
 		defer wg.Done()
-		io.Copy(os.Stdout, r) // nolint: errcheck
+		// nolint: errcheck
+		// We should check for errors here, but haven't done yet.
+		io.Copy(os.Stdout, r)
 	}()
 
 	wg.Wait()

tfschema/grpc_client.go

@@ -74,7 +74,11 @@ func newGRPCClientConfig(pluginMeta *discovery.PluginMeta, options Option) *plug
 		Logger:           options.Logger,
 		AllowedProtocols: []plugin.Protocol{plugin.ProtocolGRPC},
 		Managed:          true,
-		Cmd:              exec.Command(pluginMeta.Path), // nolint: gosec
+		// nolint: gosec
+		// G204: Subprocess launched with a potential tainted input or cmd arguments.
+		// The path of executable was found in plugin directories,
+		// which means it has a valid terraform plugin name.
+		Cmd:              exec.Command(pluginMeta.Path),
 		AutoMTLS:         true,
 		VersionedPlugins: tfplugin.VersionedPlugins,
 	}