use multiline commit msgs for pr body

Author: skarim

cmd/push.go

@@ -112,15 +112,24 @@ func runPush(cfg *config.Config, opts *pushOptions) error {
 			// Create new PR — auto-generate title from commits/branch name,
 			// then prompt interactively unless --auto or non-interactive.
 			baseBranchForDiff := s.ActiveBaseBranch(b.Branch)
-			title := defaultPRTitle(baseBranchForDiff, b.Branch)
+			title, commitBody := defaultPRTitleBody(baseBranchForDiff, b.Branch)
+			originalTitle := title
 			if !opts.auto && cfg.IsInteractive() {
 				p := prompter.New(cfg.In, cfg.Out, cfg.Err)
 				input, err := p.Input(fmt.Sprintf("Title for PR (branch %s):", b.Branch), title)
 				if err == nil && input != "" {
 					title = input
 				}
 			}
-			body := generatePRBody(s, b.Branch)
+
+			// If the user changed the title and the commit had a multi-line
+			// message, put the full commit message in the PR body so no
+			// content is lost.
+			prBody := commitBody
+			if title != originalTitle && commitBody != "" {
+				prBody = originalTitle + "\n\n" + commitBody
+			}
+			body := generatePRBody(prBody)
 
 			newPR, createErr := client.CreatePR(baseBranch, b.Branch, title, body, opts.draft)
 			if createErr != nil {
@@ -188,56 +197,33 @@ func runPush(cfg *config.Config, opts *pushOptions) error {
 	return nil
 }
 
-// defaultPRTitle generates a PR title from the branch's commits.
-// If there is exactly one commit, use its subject. Otherwise, humanize the
-// branch name (replace hyphens/underscores with spaces).
-func defaultPRTitle(base, head string) string {
+// defaultPRTitleBody generates a PR title and body from the branch's commits.
+// If there is exactly one commit, use its subject as the title and its body
+// (if any) as the PR body. Otherwise, humanize the branch name for the title.
+func defaultPRTitleBody(base, head string) (string, string) {
 	commits, err := git.LogRange(base, head)
 	if err == nil && len(commits) == 1 {
-		return commits[0].Subject
+		return commits[0].Subject, strings.TrimSpace(commits[0].Body)
 	}
-	return humanize(head)
+	return humanize(head), ""
 }
 
-// generatePRBody builds a rich PR description showing the downstack branches,
-// the current branch, and a footer with links to the CLI and feedback form.
-func generatePRBody(s *stack.Stack, currentBranch string) string {
-	var lines []string
-
-	// Current branch entry (always first)
-	lines = append(lines, fmt.Sprintf("- `%s` ← *this PR*", currentBranch))
+// generatePRBody builds a PR description from the commit body (if any)
+// and a footer linking to the CLI and feedback form.
+func generatePRBody(commitBody string) string {
+	var parts []string
 
-	// Walk downstack from just below current to the bottom, skipping merged branches
-	found := false
-	for i := len(s.Branches) - 1; i >= 0; i-- {
-		b := s.Branches[i]
-		if b.Branch == currentBranch {
-			found = true
-			continue
-		}
-		if !found {
-			continue
-		}
-		if b.IsMerged() {
-			continue
-		}
-		if b.PullRequest != nil && b.PullRequest.URL != "" {
-			lines = append(lines, fmt.Sprintf("- `%s` %s", b.Branch, b.PullRequest.URL))
-		} else {
-			lines = append(lines, fmt.Sprintf("- `%s`", b.Branch))
-		}
+	if commitBody != "" {
+		parts = append(parts, commitBody)
 	}
 
-	// Trunk entry
-	lines = append(lines, fmt.Sprintf("- `%s` (base)", s.Trunk.Branch))
-
-	body := "---\n\n**Stacked Pull Requests**\n" + strings.Join(lines, "\n")
-	body += fmt.Sprintf(
-		"\n\n<sub>Stack created with <a href=\"https://github.com/github/gh-stack\">GitHub Stacks CLI</a> • <a href=\"%s\">Give Feedback 💬</a></sub>",
+	footer := fmt.Sprintf(
+		"<sub>Stack created with <a href=\"https://github.com/github/gh-stack\">GitHub Stacks CLI</a> • <a href=\"%s\">Give Feedback 💬</a></sub>",
 		feedbackBaseURL,
 	)
+	parts = append(parts, footer)
 
-	return body
+	return strings.Join(parts, "\n\n---\n\n")
 }
 
 // humanize replaces hyphens and underscores with spaces.

cmd/push_test.go

@@ -3,119 +3,41 @@ package cmd
 import (
 	"testing"
 
-	"github.com/github/gh-stack/internal/stack"
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGeneratePRBody(t *testing.T) {
 	tests := []struct {
-		name          string
-		stack         *stack.Stack
-		currentBranch string
-		wantContains  []string
-		wantAbsent    []string
+		name         string
+		commitBody   string
+		wantContains []string
 	}{
 		{
-			name: "single branch stack",
-			stack: &stack.Stack{
-				Trunk:    stack.BranchRef{Branch: "main"},
-				Branches: []stack.BranchRef{{Branch: "feature"}},
-			},
-			currentBranch: "feature",
+			name:       "empty commit body",
+			commitBody: "",
 			wantContains: []string{
-				"---",
-				"**Stacked Pull Requests**",
-				"- `feature` ← *this PR*",
-				"- `main` (base)",
 				"GitHub Stacks CLI",
 				feedbackBaseURL,
+				"<sub>",
 			},
 		},
 		{
-			name: "multi-branch current is topmost",
-			stack: &stack.Stack{
-				Trunk: stack.BranchRef{Branch: "main"},
-				Branches: []stack.BranchRef{
-					{Branch: "part-1", PullRequest: &stack.PullRequestRef{Number: 1, URL: "https://github.com/org/repo/pull/1"}},
-					{Branch: "part-2", PullRequest: &stack.PullRequestRef{Number: 2, URL: "https://github.com/org/repo/pull/2"}},
-					{Branch: "part-3"},
-				},
-			},
-			currentBranch: "part-3",
+			name:       "with commit body",
+			commitBody: "This is a detailed description\nof the change.",
 			wantContains: []string{
-				"- `part-3` ← *this PR*",
-				"- `part-2` https://github.com/org/repo/pull/2",
-				"- `part-1` https://github.com/org/repo/pull/1",
-				"- `main` (base)",
-			},
-		},
-		{
-			name: "current is in the middle excludes upstack",
-			stack: &stack.Stack{
-				Trunk: stack.BranchRef{Branch: "main"},
-				Branches: []stack.BranchRef{
-					{Branch: "part-1", PullRequest: &stack.PullRequestRef{Number: 1, URL: "https://github.com/org/repo/pull/1"}},
-					{Branch: "part-2"},
-					{Branch: "part-3"},
-				},
-			},
-			currentBranch: "part-2",
-			wantContains: []string{
-				"- `part-2` ← *this PR*",
-				"- `part-1` https://github.com/org/repo/pull/1",
-				"- `main` (base)",
-			},
-			wantAbsent: []string{
-				"part-3",
-			},
-		},
-		{
-			name: "merged branches are skipped",
-			stack: &stack.Stack{
-				Trunk: stack.BranchRef{Branch: "main"},
-				Branches: []stack.BranchRef{
-					{Branch: "part-1", PullRequest: &stack.PullRequestRef{Number: 1, URL: "https://github.com/org/repo/pull/1", Merged: true}},
-					{Branch: "part-2", PullRequest: &stack.PullRequestRef{Number: 2, URL: "https://github.com/org/repo/pull/2"}},
-					{Branch: "part-3"},
-				},
-			},
-			currentBranch: "part-3",
-			wantContains: []string{
-				"- `part-3` ← *this PR*",
-				"- `part-2` https://github.com/org/repo/pull/2",
-				"- `main` (base)",
-			},
-			wantAbsent: []string{
-				"part-1",
-			},
-		},
-		{
-			name: "downstack branch without PR shows branch name only",
-			stack: &stack.Stack{
-				Trunk: stack.BranchRef{Branch: "main"},
-				Branches: []stack.BranchRef{
-					{Branch: "part-1"},
-					{Branch: "part-2"},
-				},
-			},
-			currentBranch: "part-2",
-			wantContains: []string{
-				"- `part-2` ← *this PR*",
-				"- `part-1`",
-				"- `main` (base)",
+				"This is a detailed description\nof the change.",
+				"GitHub Stacks CLI",
+				"<sub>",
 			},
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := generatePRBody(tt.stack, tt.currentBranch)
+			got := generatePRBody(tt.commitBody)
 			for _, want := range tt.wantContains {
 				assert.Contains(t, got, want)
 			}
-			for _, absent := range tt.wantAbsent {
-				assert.NotContains(t, got, absent)
-			}
 		})
 	}
 }

internal/git/git.go

@@ -17,6 +17,7 @@ var client = &cligit.Client{}
 type CommitInfo struct {
 	SHA     string
 	Subject string
+	Body    string
 	Time    time.Time
 }
 

internal/git/gitops.go

@@ -264,7 +264,7 @@ func (d *defaultOps) Log(ref string, maxCount int) ([]CommitInfo, error) {
 }
 
 func (d *defaultOps) LogRange(base, head string) ([]CommitInfo, error) {
-	format := "%H\t%s\t%at"
+	format := "%H%x01%B%x01%at%x00"
 	rangeSpec := base + ".." + head
 	output, err := run("log", rangeSpec, "--format="+format)
 	if err != nil {
@@ -275,21 +275,40 @@ func (d *defaultOps) LogRange(base, head string) ([]CommitInfo, error) {
 	}
 
 	var commits []CommitInfo
-	for _, line := range strings.Split(output, "\n") {
-		parts := strings.SplitN(line, "\t", 3)
+	for _, record := range strings.Split(output, "\x00") {
+		record = strings.TrimSpace(record)
+		if record == "" {
+			continue
+		}
+		parts := strings.SplitN(record, "\x01", 3)
 		if len(parts) < 3 {
 			continue
 		}
-		ts, _ := strconv.ParseInt(parts[2], 10, 64)
+		ts, _ := strconv.ParseInt(strings.TrimSpace(parts[2]), 10, 64)
+		subject, body := splitCommitMessage(parts[1])
 		commits = append(commits, CommitInfo{
 			SHA:     parts[0],
-			Subject: parts[1],
+			Subject: subject,
+			Body:    body,
 			Time:    time.Unix(ts, 0),
 		})
 	}
 	return commits, nil
 }
 
+// splitCommitMessage splits a full commit message into subject (first line)
+// and body (remaining lines with leading/trailing blank lines trimmed).
+func splitCommitMessage(msg string) (subject, body string) {
+	msg = strings.TrimSpace(msg)
+	if i := strings.IndexByte(msg, '\n'); i >= 0 {
+		subject = msg[:i]
+		body = strings.TrimSpace(msg[i+1:])
+	} else {
+		subject = msg
+	}
+	return
+}
+
 func (d *defaultOps) DiffStatRange(base, head string) (additions, deletions int, err error) {
 	output, err := run("diff", "--numstat", base+".."+head)
 	if err != nil {

internal/git/gitops_test.go

@@ -0,0 +1,61 @@
+package git
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSplitCommitMessage(t *testing.T) {
+	tests := []struct {
+		name        string
+		msg         string
+		wantSubject string
+		wantBody    string
+	}{
+		{
+			name:        "single line",
+			msg:         "Fix the bug",
+			wantSubject: "Fix the bug",
+			wantBody:    "",
+		},
+		{
+			name:        "subject and body with blank separator",
+			msg:         "Fix the bug\n\nMore details about the fix.",
+			wantSubject: "Fix the bug",
+			wantBody:    "More details about the fix.",
+		},
+		{
+			name:        "multi-line without blank separator",
+			msg:         "Fix the bug\nMore details\nEven more",
+			wantSubject: "Fix the bug",
+			wantBody:    "More details\nEven more",
+		},
+		{
+			name:        "body with leading and trailing blank lines trimmed",
+			msg:         "Fix the bug\n\n\nSome body text\n\n",
+			wantSubject: "Fix the bug",
+			wantBody:    "Some body text",
+		},
+		{
+			name:        "whitespace-only body",
+			msg:         "Fix the bug\n\n   \n\n",
+			wantSubject: "Fix the bug",
+			wantBody:    "",
+		},
+		{
+			name:        "leading whitespace on message trimmed",
+			msg:         "\n  Fix the bug\n\nBody here",
+			wantSubject: "Fix the bug",
+			wantBody:    "Body here",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			subject, body := splitCommitMessage(tt.msg)
+			assert.Equal(t, tt.wantSubject, subject)
+			assert.Equal(t, tt.wantBody, body)
+		})
+	}
+}