[GITEA] allow viewing the latest Action Run on the web

Similar to how some other parts of the web UI support a `/latest` path
to directly go to the latest of a certain thing, let the Actions web UI
do the same: `/{owner}/{repo}/actions/runs/latest` will redirect to the
latest run, if there's one available.

Fixes gitea#27991.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit f67ccef1dd)

Code cleanup in the actions.ViewLatest route handler

Based on feedback received after the feature was merged, use
`ctx.NotFound` and `ctx.ServerError`, and drop the use of the
unnecessary `ctx.Written()`.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit 74e42da563)
(cherry picked from commit f7535a1cef)
(cherry picked from commit 1a90cd37c3)
(cherry picked from commit d86d71340a)
(cherry picked from commit 9e5cce1afc)
(cherry picked from commit 2013fb3fab)
(cherry picked from commit 88b9d21d11)
(cherry picked from commit 72c020298e)

tests/integration/actions_route_test.go

@@ -0,0 +1,91 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+
+	actions_model "code.gitea.io/gitea/models/actions"
+	"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"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/git"
+	repo_service "code.gitea.io/gitea/services/repository"
+	files_service "code.gitea.io/gitea/services/repository/files"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestActionsWebRouteLatestRun(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+
+		// create the repo
+		repo, err := repo_service.CreateRepository(db.DefaultContext, user2, user2, repo_service.CreateRepoOptions{
+			Name:          "actions-latest",
+			Description:   "test /actions/runs/latest",
+			AutoInit:      true,
+			Gitignores:    "Go",
+			License:       "MIT",
+			Readme:        "Default",
+			DefaultBranch: "main",
+			IsPrivate:     false,
+		})
+		assert.NoError(t, err)
+		assert.NotEmpty(t, repo)
+
+		// enable actions
+		err = repo_service.UpdateRepositoryUnits(db.DefaultContext, repo, []repo_model.RepoUnit{{
+			RepoID: repo.ID,
+			Type:   unit_model.TypeActions,
+		}}, nil)
+		assert.NoError(t, err)
+
+		// add workflow file to the repo
+		addWorkflowToBaseResp, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, user2, &files_service.ChangeRepoFilesOptions{
+			Files: []*files_service.ChangeRepoFile{
+				{
+					Operation:     "create",
+					TreePath:      ".gitea/workflows/pr.yml",
+					ContentReader: strings.NewReader("name: test\non:\n  push:\njobs:\n  test:\n    runs-on: ubuntu-latest\n    steps:\n      - run: echo helloworld\n"),
+				},
+			},
+			Message:   "add workflow",
+			OldBranch: "main",
+			NewBranch: "main",
+			Author: &files_service.IdentityOptions{
+				Name:  user2.Name,
+				Email: user2.Email,
+			},
+			Committer: &files_service.IdentityOptions{
+				Name:  user2.Name,
+				Email: user2.Email,
+			},
+			Dates: &files_service.CommitDateOptions{
+				Author:    time.Now(),
+				Committer: time.Now(),
+			},
+		})
+		assert.NoError(t, err)
+		assert.NotEmpty(t, addWorkflowToBaseResp)
+
+		// a run has been created
+		assert.Equal(t, 1, unittest.GetCount(t, &actions_model.ActionRun{RepoID: repo.ID}))
+
+		// Hit the `/actions/runs/latest` route
+		req := NewRequest(t, "GET", fmt.Sprintf("%s/actions/runs/latest", repo.HTMLURL()))
+		resp := MakeRequest(t, req, http.StatusTemporaryRedirect)
+
+		// Verify that it redirects to the run we just created
+		expectedURI := fmt.Sprintf("%s/actions/runs/1", repo.HTMLURL())
+		assert.Equal(t, expectedURI, resp.Header().Get("Location"))
+	})
+}