treewide: parallel tests

Most tests already had no global state, however parallel was never enabled. This change enables it for all applicable tests.

Signed-off-by: Ophestra <cat@gensokyo.uk>

helper/args_test.go

@@ -11,27 +11,29 @@ import (
 )
 
 func TestArgsString(t *testing.T) {
+	t.Parallel()
 	wantString := strings.Join(wantArgs, " ")
 	if got := argsWt.(fmt.Stringer).String(); got != wantString {
-		t.Errorf("String: %q, want %q",
-			got, wantString)
+		t.Errorf("String: %q, want %q", got, wantString)
 	}
 }
 
 func TestNewCheckedArgs(t *testing.T) {
+	t.Parallel()
+
 	args := []string{"\x00"}
 	if _, err := helper.NewCheckedArgs(args); !errors.Is(err, syscall.EINVAL) {
-		t.Errorf("NewCheckedArgs: error = %v, wantErr %v",
-			err, syscall.EINVAL)
+		t.Errorf("NewCheckedArgs: error = %v, wantErr %v", err, syscall.EINVAL)
 	}
 
 	t.Run("must panic", func(t *testing.T) {
+		t.Parallel()
+
 		badPayload := []string{"\x00"}
 		defer func() {
 			wantPanic := "invalid argument"
 			if r := recover(); r != wantPanic {
-				t.Errorf("MustNewCheckedArgs: panic = %v, wantPanic %v",
-					r, wantPanic)
+				t.Errorf("MustNewCheckedArgs: panic = %v, wantPanic %v", r, wantPanic)
 			}
 		}()
 		helper.MustNewCheckedArgs(badPayload)