Add DEFAULT_TITLE_SOURCE setting for pull request title default behavior

custom/conf/app.example.ini

@@ -1169,6 +1169,11 @@ LEVEL = Info
 ;; Retarget child pull requests to the parent pull request branch target on merge of parent pull request. It only works on merged PRs where the head and base branch target the same repo.
 ;RETARGET_CHILDREN_ON_MERGE = true
 ;;
+;; Default source for the pull request title when opening a new PR.
+;; "first-commit" uses the oldest commit's summary.
+;; "auto" uses commit's summary if the PR only has one commit, normalizes the branch name if multiple commits.
+;DEFAULT_TITLE_SOURCE = first-commit
+;;
 ;; Delay mergeable check until page view or API access, for pull requests that have not been updated in the specified days when their base branches get updated.
 ;; Use "-1" to always check all pull requests (old behavior). Use "0" to always delay the checks.
 ;DELAY_CHECK_FOR_INACTIVE_DAYS = 7

modules/setting/repository.go

@@ -18,6 +18,12 @@ const (
 	RepoCreatingPublic             = "public"
 )
 
+// enumerates the values for [repository.pull-request] DEFAULT_TITLE_SOURCE
+const (
+	RepoPRTitleSourceFirstCommit = "first-commit"
+	RepoPRTitleSourceAuto        = "auto"
+)
+
 // ItemsPerPage maximum items per page in forks, watchers and stars of a repo
 const ItemsPerPage = 40
 
@@ -89,6 +95,7 @@ var (
 			RetargetChildrenOnMerge                  bool
 			DelayCheckForInactiveDays                int
 			DefaultDeleteBranchAfterMerge            bool
+			DefaultTitleSource                       string
 		} `ini:"repository.pull-request"`
 
 		// Issue Setting
@@ -213,6 +220,7 @@ var (
 			RetargetChildrenOnMerge                  bool
 			DelayCheckForInactiveDays                int
 			DefaultDeleteBranchAfterMerge            bool
+			DefaultTitleSource                       string
 		}{
 			WorkInProgressPrefixes: []string{"WIP:", "[WIP]"},
 			// Same as GitHub. See
@@ -229,6 +237,7 @@ var (
 			AddCoCommitterTrailers:                   true,
 			RetargetChildrenOnMerge:                  true,
 			DelayCheckForInactiveDays:                7,
+			DefaultTitleSource:                       RepoPRTitleSourceFirstCommit,
 		},
 
 		// Issue settings

routers/web/repo/compare.go

@@ -13,6 +13,7 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+	"unicode"
 
 	"code.gitea.io/gitea/models/db"
 	git_model "code.gitea.io/gitea/models/git"
@@ -349,13 +350,46 @@ func parseCompareInfo(ctx *context.Context) (*git_service.CompareInfo, error) {
 	return &compareInfo, nil
 }
 
-func prepareNewPullRequestTitleContent(ci *git_service.CompareInfo, commits []*git_model.SignCommitWithStatuses) (title, content string) {
-	title = ci.HeadRef.ShortName()
+// autoTitleFromBranchName humanizes a branch name into a PR title.
+func autoTitleFromBranchName(name string) string {
+	var buf strings.Builder
+	var prevIsSpace bool
+	runes := []rune(name)
+	for i, r := range runes {
+		isSpace := unicode.IsSpace(r)
+		if r == '-' || r == '_' || isSpace {
+			if !prevIsSpace {
+				buf.WriteRune(' ')
+			}
+			prevIsSpace = true
+			continue
+		}
+		if !prevIsSpace && unicode.IsUpper(r) {
+			needSpace := i > 0 && unicode.IsLower(runes[i-1]) || i < len(runes)-1 && unicode.IsLower(runes[i+1])
+			if needSpace {
+				buf.WriteRune(' ')
+			}
+		}
+		buf.WriteRune(unicode.ToLower(r))
+		prevIsSpace = isSpace
+	}
+	out := strings.TrimSpace(buf.String())
+	if out == "" {
+		return out
+	}
+	outRunes := []rune(out)
+	outRunes[0] = unicode.ToUpper(outRunes[0])
+	return string(outRunes)
+}
 
-	if len(commits) > 0 {
+func prepareNewPullRequestTitleContent(ci *git_service.CompareInfo, commits []*git_model.SignCommitWithStatuses, defaultTitleSource string) (title, content string) {
+	useFirstCommitAsTitle := len(commits) == 1 || (defaultTitleSource == setting.RepoPRTitleSourceFirstCommit && len(commits) > 0)
+	if useFirstCommitAsTitle {
 		// the "commits" are from "ShowPrettyFormatLogToList", which is ordered from newest to oldest, here take the oldest one
 		c := commits[len(commits)-1]
 		title = strings.TrimSpace(c.UserCommit.Summary())
+	} else {
+		title = autoTitleFromBranchName(ci.HeadRef.ShortName())
 	}
 
 	if len(commits) == 1 {
@@ -491,7 +525,10 @@ func prepareCompareDiff(ctx *context.Context, ci *git_service.CompareInfo, white
 	ctx.Data["Commits"] = commits
 	ctx.Data["CommitCount"] = len(commits)
 
-	ctx.Data["title"], ctx.Data["content"] = prepareNewPullRequestTitleContent(ci, commits)
+	ctx.Data["title"], ctx.Data["content"] = prepareNewPullRequestTitleContent(ci, commits, setting.Repository.PullRequest.DefaultTitleSource)
+	ctx.Data["Username"] = ci.HeadRepo.OwnerName
+	ctx.Data["Reponame"] = ci.HeadRepo.Name
+
 	setCompareContext(ctx, beforeCommit, headCommit, ci.HeadRepo.OwnerName, repo.Name)
 
 	return false

routers/web/repo/compare_test.go

@@ -13,6 +13,7 @@ import (
 	issues_model "code.gitea.io/gitea/models/issues"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/setting"
 	git_service "code.gitea.io/gitea/services/git"
 	"code.gitea.io/gitea/services/gitdiff"
 
@@ -61,31 +62,66 @@ func TestNewPullRequestTitleContent(t *testing.T) {
 		}
 	}
 
-	title, content := prepareNewPullRequestTitleContent(ci, nil)
-	assert.Equal(t, "head-branch", title)
+	// no commit
+	title, content := prepareNewPullRequestTitleContent(ci, nil, setting.RepoPRTitleSourceAuto)
+	assert.Equal(t, "Head branch", title)
 	assert.Empty(t, content)
 
-	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title-only")})
-	assert.Equal(t, "title-only", title)
+	title, content = prepareNewPullRequestTitleContent(ci, nil, setting.RepoPRTitleSourceFirstCommit)
+	assert.Equal(t, "Head branch", title)
 	assert.Empty(t, content)
 
-	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title-" + strings.Repeat("a", 255))})
-	assert.Equal(t, "title-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa…", title)
-	assert.Equal(t, "…aaaaaaaaa\n", content)
-
-	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title\nbody")})
-	assert.Equal(t, "title", title)
+	// single commit
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("single-commit-title\nbody")}, setting.RepoPRTitleSourceAuto)
+	assert.Equal(t, "single-commit-title", title)
 	assert.Equal(t, "body", content)
 
-	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("a\xf0\xf0\xf0\nb\xf0\xf0\xf0")})
-	assert.Equal(t, "a?", title) // FIXME: GIT-COMMIT-MESSAGE-ENCODING: "title" doesn't use the same charset converting logic as "content"
-	assert.Equal(t, "b"+string(utf8.RuneError)+string(utf8.RuneError), content)
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("single-commit-title\nbody")}, setting.RepoPRTitleSourceFirstCommit)
+	assert.Equal(t, "single-commit-title", title)
+	assert.Equal(t, "body", content)
 
-	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{
+	// multiple commits
+	commits := []*git_model.SignCommitWithStatuses{
 		// ordered from newest to oldest
 		mockCommit("title2\nbody2"),
 		mockCommit("title1\nbody1"),
-	})
+	}
+	title, content = prepareNewPullRequestTitleContent(ci, commits, setting.RepoPRTitleSourceAuto)
+	assert.Equal(t, "Head branch", title)
+	assert.Empty(t, content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, commits, setting.RepoPRTitleSourceFirstCommit)
 	assert.Equal(t, "title1", title)
 	assert.Empty(t, content)
+
+	// title string handling
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("title-" + strings.Repeat("a", 255))}, setting.RepoPRTitleSourceFirstCommit)
+	assert.Equal(t, "title-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa…", title)
+	assert.Equal(t, "…aaaaaaaaa\n", content)
+
+	title, content = prepareNewPullRequestTitleContent(ci, []*git_model.SignCommitWithStatuses{mockCommit("a\xf0\xf0\xf0\nb\xf0\xf0\xf0")}, setting.RepoPRTitleSourceFirstCommit)
+	assert.Equal(t, "a?", title) // FIXME: GIT-COMMIT-MESSAGE-ENCODING: "title" doesn't use the same charset converting logic as "content"
+	assert.Equal(t, "b"+string(utf8.RuneError)+string(utf8.RuneError), content)
+}
+
+func TestAutoTitleFromBranchName(t *testing.T) {
+	cases := []struct {
+		branch string
+		want   string
+	}{
+		{"fix/the-bug", "Fix/the bug"},
+		{"Already-Capitalized", "Already capitalized"},
+		{"ALL-CAPS-BRANCH", "All caps branch"},
+		{"FixHTMLBug", "Fix html bug"},
+		{"MixedCase-Name", "Mixed case name"},
+		{"fooBar-baz", "Foo bar baz"},
+		{"foo/BAR", "Foo/bar"},
+		{"_leading-underscore", "Leading underscore"},
+		{"CamelCase", "Camel case"},
+		{"foo--double-dash", "Foo double dash"},
+		{"123-fix", "123 fix"},
+	}
+	for _, c := range cases {
+		assert.Equal(t, c.want, autoTitleFromBranchName(c.branch), "branch: %q", c.branch)
+	}
 }