Ensure GetCSRF doesn't return an empty token (#32130)

Since page templates keep changing, some pages that contained forms with
CSRF token no longer have them.

It leads to some calls of `GetCSRF` returning an empty string, which
fails the tests. Like

https://github.com/go-gitea/gitea/blob/3269b04d61ffe6a7ce462cd05ee150e4491124e8/tests/integration/attachment_test.go#L62-L63

The test did try to get the CSRF token and provided it, but it was
empty.

tests/integration/attachment_test.go

@@ -29,7 +29,7 @@ func generateImg() bytes.Buffer {
 	return buff
 }
 
-func createAttachment(t *testing.T, session *TestSession, repoURL, filename string, buff bytes.Buffer, expectedStatus int) string {
+func createAttachment(t *testing.T, session *TestSession, csrf, repoURL, filename string, buff bytes.Buffer, expectedStatus int) string {
 	body := &bytes.Buffer{}
 
 	// Setup multi-part
@@ -41,8 +41,6 @@ func createAttachment(t *testing.T, session *TestSession, repoURL, filename stri
 	err = writer.Close()
 	assert.NoError(t, err)
 
-	csrf := GetCSRF(t, session, repoURL)
-
 	req := NewRequestWithBody(t, "POST", repoURL+"/issues/attachments", body)
 	req.Header.Add("X-Csrf-Token", csrf)
 	req.Header.Add("Content-Type", writer.FormDataContentType())
@@ -59,15 +57,14 @@ func createAttachment(t *testing.T, session *TestSession, repoURL, filename stri
 func TestCreateAnonymousAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 	session := emptyTestSession(t)
-	// this test is not right because it just doesn't pass the CSRF validation
-	createAttachment(t, session, "user2/repo1", "image.png", generateImg(), http.StatusBadRequest)
+	createAttachment(t, session, GetCSRF(t, session, "/user/login"), "user2/repo1", "image.png", generateImg(), http.StatusSeeOther)
 }
 
 func TestCreateIssueAttachment(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()
 	const repoURL = "user2/repo1"
 	session := loginUser(t, "user2")
-	uuid := createAttachment(t, session, repoURL, "image.png", generateImg(), http.StatusOK)
+	uuid := createAttachment(t, session, GetCSRF(t, session, repoURL), repoURL, "image.png", generateImg(), http.StatusOK)
 
 	req := NewRequest(t, "GET", repoURL+"/issues/new")
 	resp := session.MakeRequest(t, req, http.StatusOK)

tests/integration/integration_test.go

@@ -37,6 +37,7 @@ import (
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/xeipuuv/gojsonschema"
 )
 
@@ -486,12 +487,16 @@ func VerifyJSONSchema(t testing.TB, resp *httptest.ResponseRecorder, schemaFile
 }
 
 // GetCSRF returns CSRF token from body
+// If it fails, it means the CSRF token is not found in the response body returned by the url with the given session.
+// In this case, you should find a better url to get it.
 func GetCSRF(t testing.TB, session *TestSession, urlStr string) string {
 	t.Helper()
 	req := NewRequest(t, "GET", urlStr)
 	resp := session.MakeRequest(t, req, http.StatusOK)
 	doc := NewHTMLParser(t, resp.Body)
-	return doc.GetCSRF()
+	csrf := doc.GetCSRF()
+	require.NotEmpty(t, csrf)
+	return csrf
 }
 
 // GetCSRFFrom returns CSRF token from body

tests/integration/org_test.go

@@ -204,9 +204,7 @@ func TestTeamSearch(t *testing.T) {
 	var results TeamSearchResults
 
 	session := loginUser(t, user.Name)
-	csrf := GetCSRF(t, session, "/"+org.Name)
 	req := NewRequestf(t, "GET", "/org/%s/teams/-/search?q=%s", org.Name, "_team")
-	req.Header.Add("X-Csrf-Token", csrf)
 	resp := session.MakeRequest(t, req, http.StatusOK)
 	DecodeJSON(t, resp, &results)
 	assert.NotEmpty(t, results.Data)
@@ -217,8 +215,6 @@ func TestTeamSearch(t *testing.T) {
 	// no access if not organization member
 	user5 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 5})
 	session = loginUser(t, user5.Name)
-	csrf = GetCSRF(t, session, "/"+org.Name)
 	req = NewRequestf(t, "GET", "/org/%s/teams/-/search?q=%s", org.Name, "team")
-	req.Header.Add("X-Csrf-Token", csrf)
 	session.MakeRequest(t, req, http.StatusNotFound)
 }