repo: Don't redirect the repo to external units

When displaying the repo home view, do not redirect to unit types that
can't be defaults (which, at the moment, are the external wiki and issue
tracker unit types).

If we'd redirect to those, that would mean that a repository with the
Code unit disabled, and an external issue tracker would immediately
redirect to the external issue tracker, making it harder to reach other,
non-external units of the repo.

Fixes #1965.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>

routers/web/repo/view.go

@@ -681,7 +681,7 @@ func checkHomeCodeViewable(ctx *context.Context) {
 			}
 
 			unit, ok := unit_model.Units[repoUnit.Type]
-			if ok && (firstUnit == nil || !firstUnit.IsLessThan(unit)) {
+			if ok && (firstUnit == nil || !firstUnit.IsLessThan(unit)) && repoUnit.Type.CanBeDefault() {
 				firstUnit = &unit
 			}
 		}

tests/integration/repo_test.go

@@ -11,6 +11,10 @@ import (
 	"testing"
 	"time"
 
+	"code.gitea.io/gitea/models/db"
+	repo_model "code.gitea.io/gitea/models/repo"
+	unit_model "code.gitea.io/gitea/models/unit"
+	"code.gitea.io/gitea/models/unittest"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/tests"
@@ -701,3 +705,101 @@ func TestCommitView(t *testing.T) {
 		assert.Contains(t, commitTitle, "Initial commit")
 	})
 }
+
+func TestRepoHomeViewRedirect(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	t.Run("Code", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		req := NewRequest(t, "GET", "/user2/repo1")
+		resp := MakeRequest(t, req, http.StatusOK)
+
+		doc := NewHTMLParser(t, resp.Body)
+		l := doc.Find("#repo-desc").Length()
+		assert.Equal(t, 1, l)
+	})
+
+	t.Run("No Code redirects to Issues", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		// Disable the Code unit
+		repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+		err := repo_model.UpdateRepositoryUnits(db.DefaultContext, repo, nil, []unit_model.Type{
+			unit_model.TypeCode,
+		})
+		assert.NoError(t, err)
+
+		// The repo home should redirect to the built-in issue tracker
+		req := NewRequest(t, "GET", "/user2/repo1")
+		resp := MakeRequest(t, req, http.StatusSeeOther)
+		redir := resp.Header().Get("Location")
+
+		assert.Equal(t, "/user2/repo1/issues", redir)
+	})
+
+	t.Run("No Code and ExternalTracker redirects to Pulls", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		// Replace the internal tracker with an external one
+		// Disable Code, Projects, Packages, and Actions
+		repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+		err := repo_model.UpdateRepositoryUnits(db.DefaultContext, repo, []repo_model.RepoUnit{{
+			RepoID: repo.ID,
+			Type:   unit_model.TypeExternalTracker,
+			Config: &repo_model.ExternalTrackerConfig{
+				ExternalTrackerURL: "https://example.com",
+			},
+		}}, []unit_model.Type{
+			unit_model.TypeCode,
+			unit_model.TypeIssues,
+			unit_model.TypeProjects,
+			unit_model.TypePackages,
+			unit_model.TypeActions,
+		})
+		assert.NoError(t, err)
+
+		// The repo home should redirect to pull requests
+		req := NewRequest(t, "GET", "/user2/repo1")
+		resp := MakeRequest(t, req, http.StatusSeeOther)
+		redir := resp.Header().Get("Location")
+
+		assert.Equal(t, "/user2/repo1/pulls", redir)
+	})
+
+	t.Run("Only external wiki results in 404", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		// Replace the internal wiki with an external, and disable everything
+		// else.
+		repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+		err := repo_model.UpdateRepositoryUnits(db.DefaultContext, repo, []repo_model.RepoUnit{{
+			RepoID: repo.ID,
+			Type:   unit_model.TypeExternalWiki,
+			Config: &repo_model.ExternalWikiConfig{
+				ExternalWikiURL: "https://example.com",
+			},
+		}}, []unit_model.Type{
+			unit_model.TypeCode,
+			unit_model.TypeIssues,
+			unit_model.TypeExternalTracker,
+			unit_model.TypeProjects,
+			unit_model.TypePackages,
+			unit_model.TypeActions,
+			unit_model.TypePullRequests,
+			unit_model.TypeReleases,
+			unit_model.TypeWiki,
+		})
+		assert.NoError(t, err)
+
+		// The repo home ends up being 404
+		req := NewRequest(t, "GET", "/user2/repo1")
+		req.Header.Set("Accept", "text/html")
+		resp := MakeRequest(t, req, http.StatusNotFound)
+
+		// The external wiki is linked to from the 404 page
+		doc := NewHTMLParser(t, resp.Body)
+		txt := strings.TrimSpace(doc.Find(`a[href="https://example.com"]`).Text())
+		assert.Equal(t, "Wiki", txt)
+	})
+}