care -tags flag to list test cases

cmd_regexp.go

@@ -25,22 +25,22 @@ func (c *cmdRegexp) run(ctx context.Context, argv []string, outStream io.Writer,
 		return fmt.Errorf("invalid index: %s", err)
 	}
 
-	str, err := getOut(pkgs, total, idx)
+	str, err := getOut(pkgs, detectTags(argv), total, idx)
 	if err != nil {
 		return err
 	}
 	_, err = fmt.Fprintln(outStream, str)
 	return err
 }
 
-func getOut(pkgs []string, total, idx int) (string, error) {
+func getOut(pkgs []string, tags string, total, idx int) (string, error) {
 	if total < 1 {
 		return "", fmt.Errorf("invalid total: %d", total)
 	}
 	if idx >= total {
 		return "", fmt.Errorf("index shoud be between 0 to total-1, but: %d (total:%d)", idx, total)
 	}
-	testLists, err := getTestListsFromPkgs(pkgs)
+	testLists, err := getTestListsFromPkgs(pkgs, tags)
 	if err != nil {
 		return "", err
 	}

gotesplit.go

@@ -60,8 +60,12 @@ Options:
 	return run(ctx, *total, *index, *junitDir, argv, outStream, errStream)
 }
 
-func getTestListsFromPkgs(pkgs []string) ([]testList, error) {
-	args := append([]string{"test", "-list", "."}, pkgs...)
+func getTestListsFromPkgs(pkgs []string, tags string) ([]testList, error) {
+	args := []string{"test", "-list"}
+	if tags != "" {
+		args = append(args, tags)
+	}
+	args = append(append(args, "."), pkgs...)
 	buf := &bytes.Buffer{}
 	c := exec.Command("go", args...)
 	c.Stdout = buf

run.go

@@ -51,7 +51,7 @@ func run(ctx context.Context, total, idx uint, junitDir string, argv []string, o
 		}
 	}
 
-	testLists, err := getTestListsFromPkgs(pkgs)
+	testLists, err := getTestListsFromPkgs(pkgs, detectTags(argv))
 	if err != nil {
 		return err
 	}