Use GitHub-style commit message for squash merge

services/pull/pull.go

@@ -837,7 +837,8 @@ func GetSquashMergeCommitMessages(ctx context.Context, pr *issues_model.PullRequ
 	authors := make([]string, 0, len(commits))
 	stringBuilder := strings.Builder{}
 
-	if !setting.Repository.PullRequest.PopulateSquashCommentWithCommitMessages {
+	populateWithCommits := setting.Repository.PullRequest.PopulateSquashCommentWithCommitMessages
+	if !populateWithCommits {
 		message := strings.TrimSpace(pr.Issue.Content)
 		stringBuilder.WriteString(message)
 		if stringBuilder.Len() > 0 {
@@ -849,33 +850,25 @@ func GetSquashMergeCommitMessages(ctx context.Context, pr *issues_model.PullRequ
 	}
 
 	// commits list is in reverse chronological order
-	first := true
 	for i := len(commits) - 1; i >= 0; i-- {
 		commit := commits[i]
 
-		if setting.Repository.PullRequest.PopulateSquashCommentWithCommitMessages {
+		if populateWithCommits {
 			maxSize := setting.Repository.PullRequest.DefaultMergeMessageSize
 			if maxSize < 0 || stringBuilder.Len() < maxSize {
-				var toWrite []byte
-				if first {
-					first = false
-					toWrite = []byte(strings.TrimPrefix(commit.CommitMessage, pr.Issue.Title))
-				} else {
-					toWrite = []byte(commit.CommitMessage)
+				if strings.TrimSpace(commit.CommitMessage) == "" {
+					continue
 				}
 
+				toWrite := fmt.Appendf(nil, "* %s\n", commit.CommitMessage)
+
 				if len(toWrite) > maxSize-stringBuilder.Len() && maxSize > -1 {
 					toWrite = append(toWrite[:maxSize-stringBuilder.Len()], "..."...)
 				}
 				if _, err := stringBuilder.Write(toWrite); err != nil {
 					log.Error("Unable to write commit message Error: %v", err)
 					return ""
 				}
-
-				if _, err := stringBuilder.WriteRune('\n'); err != nil {
-					log.Error("Unable to write commit message Error: %v", err)
-					return ""
-				}
 			}
 		}
 
@@ -916,6 +909,10 @@ func GetSquashMergeCommitMessages(ctx context.Context, pr *issues_model.PullRequ
 		}
 	}
 
+	if stringBuilder.Len() > 0 && len(authors) > 0 {
+		stringBuilder.WriteString("---------\n\n")
+	}
+
 	for _, author := range authors {
 		if _, err := stringBuilder.WriteString("Co-authored-by: "); err != nil {
 			log.Error("Unable to write to string builder Error: %v", err)

tests/integration/api_repo_file_helpers.go

@@ -19,6 +19,9 @@ import (
 
 type createFileInBranchOptions struct {
 	OldBranch, NewBranch string
+	CommitMessage        string
+	CommitterName        string
+	CommitterEmail       string
 }
 
 func testCreateFileInBranch(t *testing.T, user *user_model.User, repo *repo_model.Repository, createOpts createFileInBranchOptions, files map[string]string) *api.FilesResponse {
@@ -29,7 +32,17 @@ func testCreateFileInBranch(t *testing.T, user *user_model.User, repo *repo_mode
 
 func createFileInBranch(user *user_model.User, repo *repo_model.Repository, createOpts createFileInBranchOptions, files map[string]string) (*api.FilesResponse, error) {
 	ctx := context.TODO()
-	opts := &files_service.ChangeRepoFilesOptions{OldBranch: createOpts.OldBranch, NewBranch: createOpts.NewBranch}
+	opts := &files_service.ChangeRepoFilesOptions{
+		OldBranch: createOpts.OldBranch,
+		NewBranch: createOpts.NewBranch,
+		Message:   createOpts.CommitMessage,
+	}
+	if createOpts.CommitterName != "" || createOpts.CommitterEmail != "" {
+		opts.Committer = &files_service.IdentityOptions{
+			GitUserName:  createOpts.CommitterName,
+			GitUserEmail: createOpts.CommitterEmail,
+		}
+	}
 	for path, content := range files {
 		opts.Files = append(opts.Files, &files_service.ChangeRepoFile{
 			Operation:     "create",

tests/integration/pull_merge_test.go

@@ -33,6 +33,7 @@ import (
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/translation"
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/automerge"
 	"code.gitea.io/gitea/services/automergequeue"
 	pull_service "code.gitea.io/gitea/services/pull"
@@ -1180,3 +1181,170 @@ func TestPullNonMergeForAdminWithBranchProtection(t *testing.T) {
 		session.MakeRequest(t, mergeReq, http.StatusMethodNotAllowed)
 	})
 }
+
+func TestPullSquashMessage(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, giteaURL *url.URL) {
+		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+		user2Session := loginUser(t, user2.Name)
+
+		defer test.MockVariableValue(&setting.Repository.PullRequest.PopulateSquashCommentWithCommitMessages, true)()
+		defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultMergeMessageSize, 512)()
+
+		repo, err := repo_service.CreateRepository(t.Context(), user2, user2, repo_service.CreateRepoOptions{
+			Name:          "squash-message-test",
+			Description:   "Test squash message",
+			AutoInit:      true,
+			Readme:        "Default",
+			DefaultBranch: "main",
+		})
+		assert.NoError(t, err)
+
+		type commitInfo struct {
+			userName      string
+			commitSummary string
+			commitMessage string
+		}
+
+		testCases := []struct {
+			name            string
+			commitInfos     []*commitInfo
+			expectedMessage string
+		}{
+			{
+				name: "Only summaries",
+				commitInfos: []*commitInfo{
+					{
+						userName:      user2.Name,
+						commitSummary: "Implement the login endpoint",
+					},
+					{
+						userName:      user2.Name,
+						commitSummary: "Validate request body",
+					},
+				},
+				expectedMessage: `* Implement the login endpoint
+
+* Validate request body
+
+`,
+			},
+			{
+				name: "Summaries and messages",
+				commitInfos: []*commitInfo{
+					{
+						userName:      user2.Name,
+						commitSummary: "Refactor user service",
+						commitMessage: `Implement the login endpoint.
+Validate request body.`,
+					},
+					{
+						userName:      user2.Name,
+						commitSummary: "Add email notification service",
+						commitMessage: `Implements a new email notification module.
+
+- Supports templating
+- Supports HTML and plain text modes
+- Includes retry logic`,
+					},
+				},
+				expectedMessage: `* Refactor user service
+
+Implement the login endpoint.
+Validate request body.
+
+* Add email notification service
+
+Implements a new email notification module.
+
+- Supports templating
+- Supports HTML and plain text modes
+- Includes retry logic
+
+`,
+			},
+			{
+				name: "Long Message",
+				commitInfos: []*commitInfo{
+					{
+						userName:      user2.Name,
+						commitSummary: "Add advanced validation logic for user onboarding",
+						commitMessage: `This commit introduces a comprehensive validation layer for the user onboarding flow.
+The primary goal is to ensure that all input data is strictly validated before being processed by downstream services.
+This improves system reliability and significantly reduces runtime exceptions in the registration pipeline.
+
+The validation logic includes:
+
+1. Email format checking using RFC 5322-compliant patterns.
+2. Username length and character limitation enforcement.
+3. Password strength enforcement, including:
+   - Minimum length checks
+   - Mixed character type detection
+   - Optional entropy-based scoring
+4. Optional phone number validation using region-specific rules.
+`,
+					},
+				},
+				expectedMessage: `* Add advanced validation logic for user onboarding
+
+This commit introduces a comprehensive validation layer for the user onboarding flow.
+The primary goal is to ensure that all input data is strictly validated before being processed by downstream services.
+This improves system reliability and significantly reduces runtime exceptions in the registration pipeline.
+
+The validation logic includes:
+
+1. Email format checking using RFC 5322-compliant patterns.
+2. Username length and character limitation enforceme...`,
+			},
+			{
+				name: "Test Co-authored-by",
+				commitInfos: []*commitInfo{
+					{
+						userName:      user2.Name,
+						commitSummary: "Implement the login endpoint",
+					},
+					{
+						userName:      "user4",
+						commitSummary: "Validate request body",
+					},
+				},
+				expectedMessage: `* Implement the login endpoint
+
+* Validate request body
+
+---------
+
+Co-authored-by: user4 <[email protected]>
+`,
+			},
+		}
+
+		for tcNum, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				branchName := "test-branch-" + strconv.Itoa(tcNum)
+				for infoIdx, info := range tc.commitInfos {
+					createFileOpts := createFileInBranchOptions{
+						CommitMessage:  info.commitSummary + "\n\n" + info.commitMessage,
+						CommitterName:  info.userName,
+						CommitterEmail: util.Iif(info.userName != "", info.userName+"@example.com", ""),
+						OldBranch:      util.Iif(infoIdx == 0, "main", branchName),
+						NewBranch:      branchName,
+					}
+					testCreateFileInBranch(t, user2, repo, createFileOpts, map[string]string{"dummy-file-" + strconv.Itoa(infoIdx): "dummy content"})
+				}
+				resp := testPullCreateDirectly(t, user2Session, createPullRequestOptions{
+					BaseRepoOwner: user2.Name,
+					BaseRepoName:  repo.Name,
+					BaseBranch:    repo.DefaultBranch,
+					HeadBranch:    branchName,
+					Title:         "Pull for " + branchName,
+				})
+				elems := strings.Split(test.RedirectURL(resp), "/")
+				pullIndex, err := strconv.Atoi(elems[4])
+				assert.NoError(t, err)
+				pullRequest := unittest.AssertExistsAndLoadBean(t, &issues_model.PullRequest{BaseRepoID: repo.ID, Index: int64(pullIndex)})
+				squashMergeCommitMessage := pull_service.GetSquashMergeCommitMessages(t.Context(), pullRequest)
+				assert.Equal(t, tc.expectedMessage, squashMergeCommitMessage)
+			})
+		}
+	})
+}