fix: return API URL in the url field for pull requests using the API (#12643)

closes #10451

### Tests for Go changes

- I added test coverage for Go changes...
  - [x] in their respective `*_test.go` for unit tests.
  - [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I ran...
  - [ ] `make pr-go` before pushing

### Release notes

- [x] This change will be noticed by a Forgejo user or admin (feature, bug fix, performance, etc.). I suggest to include a release note for this change.
- [ ] This change is not visible to a Forgejo user or admin (refactor, dependency upgrade, etc.). I think there is no need to add a release note for this change.

<!--start release-notes-assistant-->

## Release notes
<!--URL:https://codeberg.org/forgejo/forgejo-->
- Bug fixes
  - [PR](https://codeberg.org/forgejo/forgejo/pulls/12643): <!--number 12643 --><!--line 0 --><!--description cmV0dXJuIEFQSSBVUkwgaW4gdGhlIGB1cmxgIGZpZWxkIGZvciBwdWxsIHJlcXVlc3RzIHVzaW5nIHRoZSBBUEk=-->return API URL in the `url` field for pull requests using the API<!--description-->
<!--end release-notes-assistant-->

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12643
Reviewed-by: Robert Wolff <mahlzahn@posteo.de>
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>

models/issues/issue.go

@@ -386,7 +386,14 @@ func (issue *Issue) APIURL(ctx context.Context) string {
 			return ""
 		}
 	}
-	return fmt.Sprintf("%s/issues/%d", issue.Repo.APIURL(), issue.Index)
+
+	var path string
+	if issue.IsPull {
+		path = "pulls"
+	} else {
+		path = "issues"
+	}
+	return fmt.Sprintf("%s/%s/%d", issue.Repo.APIURL(), path, issue.Index)
 }
 
 // HTMLURL returns the absolute URL to this issue.

models/issues/issue_test.go

@@ -67,6 +67,10 @@ func TestIssueAPIURL(t *testing.T) {
 
 	require.NoError(t, err)
 	assert.Equal(t, "https://try.gitea.io/api/v1/repos/user2/repo1/issues/1", issue.APIURL(db.DefaultContext))
+
+	pr := unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{ID: 1})
+	require.NoError(t, pr.LoadIssue(db.DefaultContext))
+	assert.Equal(t, "https://try.gitea.io/api/v1/repos/user2/repo1/pulls/2", pr.Issue.APIURL(db.DefaultContext))
 }
 
 func TestGetIssuesByIDs(t *testing.T) {

services/convert/pull.go

@@ -67,7 +67,7 @@ func ToAPIPullRequest(ctx context.Context, pr *issues_model.PullRequest, doer *u
 
 	apiPullRequest := &api.PullRequest{
 		ID:                      pr.ID,
-		URL:                     pr.Issue.HTMLURL(),
+		URL:                     pr.Issue.APIURL(ctx),
 		Index:                   pr.Index,
 		Poster:                  apiIssue.Poster,
 		Title:                   apiIssue.Title,

tests/integration/actions_trust_test.go

@@ -534,7 +534,7 @@ func TestActionsPullRequestTrustCancelOnClose(t *testing.T) {
 
 		regularUser := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 5})
 		regularSession := loginUser(t, regularUser.Name)
-		token := getTokenForLoggedInUser(t, regularSession, auth_model.AccessTokenScopeWriteIssue)
+		token := getTokenForLoggedInUser(t, regularSession, auth_model.AccessTokenScopeWriteRepository)
 
 		baseRepo, f := actionsTrustTestCreateBaseRepo(t, ownerUser)
 		defer f()

tests/integration/api_pull_test.go

@@ -299,6 +299,7 @@ func TestAPICreatePullSuccess(t *testing.T) {
 	DecodeJSON(t, res, pull)
 
 	assert.Equal(t, "65f1bf27bc3bf70f64657658635e66094edbcb4d", pull.MergeBase)
+	assert.Contains(t, pull.URL, fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d", owner10.Name, repo10.Name, pull.Index))
 }
 
 func TestAPICreatePullSameRepoSuccess(t *testing.T) {