updated storage format

Author: skarim

cmd/add.go

@@ -98,8 +98,8 @@ func runAdd(cfg *config.Config, args []string) error {
 		return nil
 	}
 
-	head, _ := git.HeadSHA(branchName)
-	s.Branches = append(s.Branches, stack.BranchRef{Branch: branchName, Head: head})
+	base, _ := git.HeadSHA(currentBranch)
+	s.Branches = append(s.Branches, stack.BranchRef{Branch: branchName, Base: base})
 
 	if err := stack.Save(gitDir, sf); err != nil {
 		cfg.Errorf("failed to save stack state: %s", err)

cmd/init.go

@@ -71,7 +71,7 @@ func runInit(cfg *config.Config, opts *initOptions) error {
 	// Set repository context
 	repo, err := cfg.Repo()
 	if err == nil {
-		sf.Repository = repo.Owner + "/" + repo.Name
+		sf.Repository = repo.Host + ":" + repo.Owner + "/" + repo.Name
 	}
 
 	currentBranch, _ := git.CurrentBranch()
@@ -169,8 +169,12 @@ func runInit(cfg *config.Config, opts *initOptions) error {
 	trunkSHA, _ := git.HeadSHA(trunk)
 	branchRefs := make([]stack.BranchRef, len(branches))
 	for i, b := range branches {
-		sha, _ := git.HeadSHA(b)
-		branchRefs[i] = stack.BranchRef{Branch: b, Head: sha}
+		parent := trunk
+		if i > 0 {
+			parent = branches[i-1]
+		}
+		base, _ := git.MergeBase(b, parent)
+		branchRefs[i] = stack.BranchRef{Branch: b, Base: base}
 	}
 
 	newStack := stack.Stack{

cmd/push.go

@@ -114,6 +114,12 @@ func runPush(cfg *config.Config, opts *pushOptions) error {
 				continue
 			}
 			cfg.Successf("Created PR #%d for %s\n", newPR.Number, b.Branch)
+			s.Branches[i].PullRequest = &stack.PullRequestRef{
+				Number: newPR.Number,
+				ID:     newPR.ID,
+				URL:    newPR.URL,
+				Title:  newPR.Title,
+			}
 		} else {
 			// Update base if needed
 			if pr.BaseRefName != baseBranch {
@@ -125,6 +131,14 @@ func runPush(cfg *config.Config, opts *pushOptions) error {
 			} else {
 				cfg.Printf("PR #%d for %s is up to date\n", pr.Number, b.Branch)
 			}
+			if s.Branches[i].PullRequest == nil {
+				s.Branches[i].PullRequest = &stack.PullRequestRef{
+					Number: pr.Number,
+					ID:     pr.ID,
+					URL:    pr.URL,
+					Title:  pr.Title,
+				}
+			}
 		}
 	}
 
@@ -138,10 +152,14 @@ func runPush(cfg *config.Config, opts *pushOptions) error {
 	fmt.Fprintf(cfg.Err, "  Once the GitHub Stacks API is available, PRs will be automatically\n")
 	fmt.Fprintf(cfg.Err, "  grouped into a Stack.\n")
 
-	// Update head SHAs
-	for i, b := range s.Branches {
-		if sha, err := git.HeadSHA(b.Branch); err == nil {
-			s.Branches[i].Head = sha
+	// Update base commit hashes
+	for i := range s.Branches {
+		parent := s.Trunk.Branch
+		if i > 0 {
+			parent = s.Branches[i-1].Branch
+		}
+		if base, err := git.HeadSHA(parent); err == nil {
+			s.Branches[i].Base = base
 		}
 	}
 

cmd/rebase.go

@@ -200,8 +200,12 @@ func runRebase(cfg *config.Config, opts *rebaseOptions) error {
 	_ = git.CheckoutBranch(currentBranch)
 
 	for i := range s.Branches {
-		sha, _ := git.HeadSHA(s.Branches[i].Branch)
-		s.Branches[i].Head = sha
+		parent := s.Trunk.Branch
+		if i > 0 {
+			parent = s.Branches[i-1].Branch
+		}
+		base, _ := git.HeadSHA(parent)
+		s.Branches[i].Base = base
 	}
 	_ = stack.Save(gitDir, sf)
 
@@ -312,8 +316,12 @@ func continueRebase(cfg *config.Config, gitDir string) error {
 	_ = git.CheckoutBranch(state.OriginalBranch)
 
 	for i := range s.Branches {
-		sha, _ := git.HeadSHA(s.Branches[i].Branch)
-		s.Branches[i].Head = sha
+		parent := s.Trunk.Branch
+		if i > 0 {
+			parent = s.Branches[i-1].Branch
+		}
+		base, _ := git.HeadSHA(parent)
+		s.Branches[i].Base = base
 	}
 	_ = stack.Save(gitDir, sf)
 

internal/git/git.go

@@ -207,6 +207,11 @@ func HeadSHA(ref string) (string, error) {
 	return run("rev-parse", ref)
 }
 
+// MergeBase returns the best common ancestor commit between two refs.
+func MergeBase(a, b string) (string, error) {
+	return run("merge-base", a, b)
+}
+
 // Log returns recent commits for the given branch.
 func Log(ref string, maxCount int) ([]CommitInfo, error) {
 	format := "%H\t%s\t%at"

internal/stack/stack.go

@@ -13,14 +13,30 @@ const (
 	stackFileName = "gh-stack"
 )
 
-// BranchRef represents a branch and its HEAD commit.
+// PullRequestRef holds relatively immutable metadata about an associated PR.
+type PullRequestRef struct {
+	Number int    `json:"number"`
+	ID     string `json:"id,omitempty"`
+	URL    string `json:"url,omitempty"`
+	Title  string `json:"title,omitempty"`
+}
+
+// BranchRef represents a branch and its associated commit hash.
+// For the trunk, Head stores the HEAD commit SHA.
+// For stacked branches, Base stores the merge-base commit SHA
+// (the last common commit before divergence from the parent branch).
 type BranchRef struct {
-	Branch string `json:"branch"`
-	Head   string `json:"head"`
+	Branch      string          `json:"branch"`
+	Head        string          `json:"head,omitempty"`
+	Base        string          `json:"base,omitempty"`
+	PullRequest *PullRequestRef `json:"pullRequest,omitempty"`
 }
 
 // Stack represents a single stack of branches.
 type Stack struct {
+	ID       string      `json:"id,omitempty"`
+	State    string      `json:"state,omitempty"`
+	Open     bool        `json:"open,omitempty"`
 	Trunk    BranchRef   `json:"trunk"`
 	Branches []BranchRef `json:"branches"`
 }
@@ -144,6 +160,7 @@ func Load(gitDir string) (*StackFile, error) {
 	if err := json.Unmarshal(data, &sf); err != nil {
 		return nil, fmt.Errorf("parsing stack file: %w", err)
 	}
+
 	return &sf, nil
 }