state: Couple drafts to branch lifecycle

internal/spice/state/branch.go

@@ -354,6 +354,7 @@ func (tx *BranchTx) Delete(ctx context.Context, name string) error {
 }
 
 // Rename changes a tracked branch name while preserving its stored state.
+// Commit also moves state owned by the branch, such as review drafts.
 func (tx *BranchTx) Rename(
 	ctx context.Context,
 	oldName, newName string,
@@ -582,16 +583,28 @@ func (s *Store) updateBranches(ctx context.Context, req updateBranchesRequest) e
 	var dels []string
 	for _, del := range req.Deletes {
 		if _, renamed := req.Renames[del]; !renamed {
-			dels = append(dels, branchKey(del))
+			dels = append(
+				dels,
+				branchKey(del),
+				reviewDraftsJSON(del),
+			)
 		}
 	}
 
 	var moves []storage.MoveRequest
 	for _, oldName := range slices.Sorted(maps.Keys(req.Renames)) {
-		moves = append(moves, storage.MoveRequest{
-			From: branchKey(oldName),
-			To:   branchKey(req.Renames[oldName]),
-		})
+		newName := req.Renames[oldName]
+		moves = append(
+			moves,
+			storage.MoveRequest{
+				From: branchKey(oldName),
+				To:   branchKey(newName),
+			},
+			storage.MoveRequest{
+				From: reviewDraftsJSON(oldName),
+				To:   reviewDraftsJSON(newName),
+			},
+		)
 	}
 
 	updReq := storage.UpdateRequest{

internal/spice/state/review_draft.go

@@ -45,6 +45,7 @@ func (s *Store) AddReviewDraft(
 		storage.JSONMutationRequest{
 			Key:       reviewDraftsJSON(branch),
 			IfMissing: jsontext.Value(`{}`),
+			Requires:  []string{branchKey(branch)},
 			Message:   fmt.Sprintf("%v: add review draft", branch),
 		},
 		jsonmut.InsertAutoIncrement(
@@ -77,6 +78,7 @@ func (s *Store) UpdateReviewDraftBody(
 		storage.JSONMutationRequest{
 			Key:       reviewDraftsJSON(branch),
 			IfMissing: jsontext.Value(`{}`),
+			Requires:  []string{branchKey(branch)},
 			Message:   fmt.Sprintf("%v: update review draft", branch),
 		},
 		jsonmut.Replace(

internal/spice/state/review_draft_concurrency_test.go

@@ -11,6 +11,7 @@ import (
 	"go.abhg.dev/gs/internal/review"
 	"go.abhg.dev/gs/internal/silog/silogtest"
 	"go.abhg.dev/gs/internal/spice/state"
+	"go.abhg.dev/gs/internal/spice/state/statetest"
 	"go.abhg.dev/gs/internal/spice/state/storage"
 )
 
@@ -159,6 +160,14 @@ func newConcurrentReviewDraftStores(
 		stores[i], err = state.OpenStore(ctx, db, silogtest.New(t))
 		require.NoError(t, err)
 	}
+	require.NoError(t, statetest.UpdateBranch(
+		ctx,
+		stores[0],
+		&statetest.UpdateRequest{
+			Upserts: []state.UpsertRequest{{Name: "feat", Base: "main"}},
+			Message: "track feat",
+		},
+	))
 	return stores, pausingRepo
 }
 

internal/spice/state/review_draft_test.go

@@ -20,6 +20,12 @@ func TestReviewDrafts(t *testing.T) {
 		Trunk: "main",
 	})
 	require.NoError(t, err)
+	tx := store.BeginBranchTx()
+	require.NoError(t, tx.Upsert(ctx, state.UpsertRequest{
+		Name: "feature",
+		Base: "main",
+	}))
+	require.NoError(t, tx.Commit(ctx, "track feature"))
 
 	comment, err := store.AddReviewDraft(
 		ctx,
@@ -62,3 +68,137 @@ func TestReviewDrafts(t *testing.T) {
 	require.NoError(t, err)
 	assert.Nil(t, drafts)
 }
+
+func TestReviewDraftsFollowBranchLifecycle(t *testing.T) {
+	t.Parallel()
+
+	t.Run("Delete", func(t *testing.T) {
+		ctx := t.Context()
+		db := storage.NewDB(make(storage.MapBackend))
+		store, err := state.InitStore(ctx, state.InitStoreRequest{
+			DB:    db,
+			Trunk: "main",
+		})
+		require.NoError(t, err)
+
+		tx := store.BeginBranchTx()
+		require.NoError(t, tx.Upsert(ctx, state.UpsertRequest{
+			Name: "feature",
+			Base: "main",
+		}))
+		require.NoError(t, tx.Commit(ctx, "track feature"))
+
+		_, err = store.AddReviewDraft(
+			ctx,
+			"feature",
+			review.Draft{
+				ID:   0,
+				Body: "comment body",
+				Anchor: review.Anchor{
+					Path:      "main.go",
+					StartLine: 42,
+					EndLine:   42,
+				},
+			},
+		)
+		require.NoError(t, err)
+
+		tx = store.BeginBranchTx()
+		require.NoError(t, tx.Delete(ctx, "feature"))
+		require.NoError(t, tx.Commit(ctx, "untrack feature"))
+
+		drafts, err := store.LoadReviewDrafts(ctx, "feature")
+		require.NoError(t, err)
+		assert.Nil(t, drafts)
+	})
+
+	t.Run("Rename", func(t *testing.T) {
+		ctx := t.Context()
+		db := storage.NewDB(make(storage.MapBackend))
+		store, err := state.InitStore(ctx, state.InitStoreRequest{
+			DB:    db,
+			Trunk: "main",
+		})
+		require.NoError(t, err)
+
+		tx := store.BeginBranchTx()
+		require.NoError(t, tx.Upsert(ctx, state.UpsertRequest{
+			Name: "feature",
+			Base: "main",
+		}))
+		require.NoError(t, tx.Commit(ctx, "track feature"))
+
+		_, err = store.AddReviewDraft(
+			ctx,
+			"feature",
+			review.Draft{
+				ID:   0,
+				Body: "comment body",
+				Anchor: review.Anchor{
+					Path:      "main.go",
+					StartLine: 42,
+					EndLine:   42,
+				},
+			},
+		)
+		require.NoError(t, err)
+
+		tx = store.BeginBranchTx()
+		require.NoError(t, tx.Rename(ctx, "feature", "renamed"))
+		require.NoError(t, tx.Commit(ctx, "rename feature"))
+
+		drafts, err := store.LoadReviewDrafts(ctx, "feature")
+		require.NoError(t, err)
+		assert.Nil(t, drafts)
+
+		drafts, err = store.LoadReviewDrafts(ctx, "renamed")
+		require.NoError(t, err)
+		require.Len(t, drafts, 1)
+		assert.Equal(t, "comment body", drafts[0].Body)
+
+		added, err := store.AddReviewDraft(
+			ctx,
+			"renamed",
+			review.Draft{
+				ID:   0,
+				Body: "second comment",
+				Anchor: review.Anchor{
+					Path:      "main.go",
+					StartLine: 42,
+					EndLine:   42,
+				},
+			},
+		)
+		require.NoError(t, err)
+		assert.Equal(t, review.DraftID(2), added.ID)
+	})
+
+	t.Run("Untracked", func(t *testing.T) {
+		ctx := t.Context()
+		db := storage.NewDB(make(storage.MapBackend))
+		store, err := state.InitStore(ctx, state.InitStoreRequest{
+			DB:    db,
+			Trunk: "main",
+		})
+		require.NoError(t, err)
+
+		_, err = store.AddReviewDraft(
+			ctx,
+			"feature",
+			review.Draft{
+				ID:   0,
+				Body: "comment body",
+				Anchor: review.Anchor{
+					Path:      "main.go",
+					StartLine: 42,
+					EndLine:   42,
+				},
+			},
+		)
+		assert.ErrorIs(t, err, state.ErrNotExist)
+
+		drafts, err := store.LoadReviewDrafts(ctx, "feature")
+		require.NoError(t, err)
+		assert.Nil(t, drafts)
+	})
+}