feat(ui): show link to download directory (#4736)

This adds links to download a directory as archive. This can be useful if you e.g. just want to download a assets directory instead of the full source tree. The logic already exists in the backend, so only the frontend had been changed.

![grafik](https://codeberg.org/attachments/bee69268-ed03-4a05-8505-3d11e977a82c)

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/4736
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: JakobDev <jakobdev@gmx.de>
Co-committed-by: JakobDev <jakobdev@gmx.de>

templates/repo/home.tmpl

@@ -144,6 +144,17 @@
 					<a class="ui button" href="{{.RepoLink}}/commits/{{.BranchNameSubURL}}/{{.TreePath | PathEscapeSegments}}">
 						{{svg "octicon-history" 16 "tw-mr-2"}}{{ctx.Locale.Tr "repo.file_history"}}
 					</a>
+					{{if not $.DisableDownloadSourceArchives}}
+						<div class="clone-panel ui action tiny input">
+							<button class="ui small jump dropdown icon button" data-tooltip-content="{{ctx.Locale.Tr "repo.more_operations"}}">
+								{{svg "octicon-kebab-horizontal"}}
+								<div class="menu">
+									<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments (printf "%s:%s" $.RefName .TreePath)}}.zip" rel="nofollow">{{svg "octicon-file-zip" 16 "tw-mr-2"}}{{ctx.Locale.Tr "repo.download_zip"}}</a>
+									<a class="item archive-link" href="{{$.RepoLink}}/archive/{{PathEscapeSegments (printf "%s:%s" $.RefName .TreePath)}}.tar.gz" rel="nofollow">{{svg "octicon-file-zip" 16 "tw-mr-2"}}{{ctx.Locale.Tr "repo.download_tar"}}</a>
+								</div>
+							</button>
+						</div>
+					{{end}}
 				{{end}}
 			</div>
 		</div>

tests/integration/repo_archive_test.go

@@ -4,10 +4,17 @@
 package integration
 
 import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"testing"
 
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/routers"
@@ -32,3 +39,47 @@ func TestRepoDownloadArchive(t *testing.T) {
 	assert.Empty(t, resp.Header().Get("Content-Encoding"))
 	assert.Len(t, bs, 320)
 }
+
+func TestRepoDownloadArchiveSubdir(t *testing.T) {
+	onGiteaRun(t, func(*testing.T, *url.URL) {
+		defer test.MockVariableValue(&setting.EnableGzip, true)()
+		defer test.MockVariableValue(&web.GzipMinSize, 10)()
+		defer test.MockVariableValue(&testWebRoutes, routers.NormalRoutes())()
+
+		repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+		user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: repo.OwnerID})
+
+		// Create a subdirectory
+		err := createOrReplaceFileInBranch(user, repo, "subdir/test.txt", "master", "Test")
+		require.NoError(t, err)
+
+		t.Run("Frontend", func(t *testing.T) {
+			resp := MakeRequest(t, NewRequestf(t, "GET", "/%s/src/branch/master/subdir", repo.FullName()), http.StatusOK)
+
+			assert.Contains(t, resp.Body.String(), fmt.Sprintf("/%s/archive/master:subdir.zip", repo.FullName()))
+			assert.Contains(t, resp.Body.String(), fmt.Sprintf("/%s/archive/master:subdir.tar.gz", repo.FullName()))
+		})
+
+		t.Run("Backend", func(t *testing.T) {
+			resp := MakeRequest(t, NewRequestf(t, "GET", "/%s/archive/master:subdir.tar.gz", repo.FullName()), http.StatusOK)
+
+			uncompressedStream, err := gzip.NewReader(resp.Body)
+			require.NoError(t, err)
+
+			tarReader := tar.NewReader(uncompressedStream)
+
+			header, err := tarReader.Next()
+			require.NoError(t, err)
+			assert.Equal(t, tar.TypeDir, int32(header.Typeflag))
+			assert.Equal(t, fmt.Sprintf("%s/", repo.Name), header.Name)
+
+			header, err = tarReader.Next()
+			require.NoError(t, err)
+			assert.Equal(t, tar.TypeReg, int32(header.Typeflag))
+			assert.Equal(t, fmt.Sprintf("%s/test.txt", repo.Name), header.Name)
+
+			_, err = tarReader.Next()
+			assert.Equal(t, io.EOF, err)
+		})
+	})
+}