feat(cli): default --clear-data on so runs start fresh

cmd/sanderling/main.go

@@ -52,7 +52,7 @@ func parseTestArgs(args []string, stderr io.Writer) (testOptions, error) {
 	flagSet.DurationVar(&options.duration, "duration", 5*time.Minute, "total test duration")
 	flagSet.Int64Var(&options.seed, "seed", 0, "RNG seed (0 = random)")
 	flagSet.StringVar(&options.output, "output", "./runs", "output directory for traces")
-	flagSet.BoolVar(&options.clearData, "clear-data", false, "clear app data before launching so the run starts from a fresh install")
+	flagSet.BoolVar(&options.clearData, "clear-data", true, "clear app data before launching so each run starts from a fresh install; pass --clear-data=false to resume prior state")
 	if err := flagSet.Parse(args); err != nil {
 		return testOptions{}, err
 	}

cmd/sanderling/main_test.go

@@ -32,22 +32,22 @@ func TestParseTestArgs_Defaults(t *testing.T) {
 	if options.seed != 0 {
 		t.Errorf("seed default: got %d, want 0", options.seed)
 	}
-	if options.clearData {
-		t.Errorf("clearData default: got true, want false")
+	if !options.clearData {
+		t.Errorf("clearData default: got false, want true")
 	}
 }
 
-func TestParseTestArgs_ClearDataFlag(t *testing.T) {
+func TestParseTestArgs_ClearDataDisabled(t *testing.T) {
 	options, err := parseTestArgs([]string{
 		"--spec", "s.ts",
 		"--bundle-id", "com.example",
-		"--clear-data",
+		"--clear-data=false",
 	}, io.Discard)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
-	if !options.clearData {
-		t.Errorf("expected clearData=true, got false")
+	if options.clearData {
+		t.Errorf("expected clearData=false, got true")
 	}
 }