cmd/pkgserver: appropriately mark test helpers

This improves usefulness of test log messages.

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

cmd/pkgserver/main_test.go

@@ -12,6 +12,8 @@ import (
 
 // newIndex returns the address of a newly populated packageIndex.
 func newIndex(t *testing.T) *packageIndex {
+	t.Helper()
+
 	var index packageIndex
 	if err := index.populate(nil, nil); err != nil {
 		t.Fatalf("populate: error = %v", err)
@@ -21,6 +23,8 @@ func newIndex(t *testing.T) *packageIndex {
 
 // checkStatus checks response status code.
 func checkStatus(t *testing.T, resp *http.Response, want int) {
+	t.Helper()
+
 	if resp.StatusCode != want {
 		t.Errorf(
 			"StatusCode: %s, want %s",
@@ -32,6 +36,8 @@ func checkStatus(t *testing.T, resp *http.Response, want int) {
 
 // checkHeader checks the value of a header entry.
 func checkHeader(t *testing.T, h http.Header, key, want string) {
+	t.Helper()
+
 	if got := h.Get(key); got != want {
 		t.Errorf("%s: %q, want %q", key, got, want)
 	}
@@ -39,6 +45,8 @@ func checkHeader(t *testing.T, h http.Header, key, want string) {
 
 // checkAPIHeader checks common entries set for API endpoints.
 func checkAPIHeader(t *testing.T, h http.Header) {
+	t.Helper()
+
 	checkHeader(t, h, "Content-Type", "application/json; charset=utf-8")
 	checkHeader(t, h, "Cache-Control", "no-cache, no-store, must-revalidate")
 	checkHeader(t, h, "Pragma", "no-cache")
@@ -51,12 +59,14 @@ func checkPayloadFunc[T any](
 	resp *http.Response,
 	f func(got *T) bool,
 ) {
+	t.Helper()
+
 	var got T
 	r := io.Reader(resp.Body)
 	if testing.Verbose() {
 		var buf bytes.Buffer
 		r = io.TeeReader(r, &buf)
-		defer func() { t.Log(buf.String()) }()
+		defer func() { t.Helper(); t.Log(buf.String()) }()
 	}
 	if err := json.NewDecoder(r).Decode(&got); err != nil {
 		t.Fatalf("Decode: error = %v", err)
@@ -69,12 +79,16 @@ func checkPayloadFunc[T any](
 
 // checkPayload checks the JSON response of an API endpoint.
 func checkPayload[T any](t *testing.T, resp *http.Response, want T) {
+	t.Helper()
+
 	checkPayloadFunc(t, resp, func(got *T) bool {
 		return reflect.DeepEqual(got, &want)
 	})
 }
 
 func checkError(t *testing.T, resp *http.Response, error string, code int) {
+	t.Helper()
+
 	checkStatus(t, resp, code)
 	if got, _ := io.ReadAll(resp.Body); string(got) != fmt.Sprintln(error) {
 		t.Errorf("Body: %q, want %q", string(got), error)