fix: stop dropping a review thread's fifty-first comment

docs/superpowers/2026-09-08-phase3-checks-followups.md

@@ -3,7 +3,8 @@
 checks ビュー（`docs/superpowers/plans/2026-09-07-phase3-checks.md`）を入れたときに
 見つかったが、そのブランチでは直さないと決めたもの。**直さないと決めた理由も書く。**
 
-実端末での確認は別で、`docs/superpowers/2026-09-07-phase3-checks-handoff.md` にある。
+実端末での確認は別で、checks は `docs/superpowers/2026-09-07-phase3-checks-handoff.md`、
+merge は `docs/superpowers/2026-09-08-phase3-merge-handoff.md` にある。
 
 **2026-09-08 に、直し方が決まっていたものを全部片付けた。**
 `arrange` のバケツ分け、`enter` / `L` が出せないログを取りに行く件、`follow()` が
@@ -40,12 +41,12 @@ run の無い check には見出しを描かない。結果として、そうい
 
 ## Phase 3 の残り
 
-merge（spec §4.4.4）は入った。実端末での確認は
-`docs/superpowers/2026-09-08-phase3-merge-handoff.md` にある。
+Phase 3 は完了した。checks、merge（spec §4.4.4）、ページング（各スレッドの
+`comments` が 50 件を超えても取れること）の 3 本が全部入った。
+残っているのは、上の設計判断（App が作った check run の見分け）だけである。
 
-残っているのはページングだけである:
-
-- **ページング** — 各スレッドの `comments`（`first: 50`）、
-  `docs/superpowers/plans/2026-09-08-phase3-comment-paging.md`
-
-`docs/superpowers/specs/2026-09-07-phase3-design.md` §7 にある。
+`internal/gh/cli/thread_comments.graphql` は PR #59 のスレッド
+`PRRT_kwDOTVXF-M6fwhR-` に対して実際に叩いて確認した。
+`data.node.comments.nodes` にコメント 1 件（`body` / `createdAt` /
+`author.login` / `pullRequestReview.state` を含む）が返り、`pageInfo` も
+一緒に返ってきた。

internal/gh/cli/review.go

@@ -30,6 +30,9 @@ var reviewAtOnceMutation string
 //go:embed discard_review.graphql
 var discardReviewMutation string
 
+//go:embed thread_comments.graphql
+var threadCommentsQuery string
+
 // repoArgs names the repository for a GraphQL call.
 //
 // GraphQL's repository() takes owner and name separately, unlike `gh pr`
@@ -80,6 +83,9 @@ type reviewContextResponse struct {
 }
 
 type threadNode struct {
+	// ID is not put into the domain type: only thread_comments.graphql
+	// uses it, and it never reaches the screen.
+	ID         string `json:"id"`
 	IsResolved bool   `json:"isResolved"`
 	IsOutdated bool   `json:"isOutdated"`
 	Path       string `json:"path"`
@@ -89,7 +95,8 @@ type threadNode struct {
 	OriginalLine int    `json:"originalLine"`
 	DiffSide     string `json:"diffSide"`
 	Comments     struct {
-		Nodes []threadCommentNode `json:"nodes"`
+		PageInfo pageInfo            `json:"pageInfo"`
+		Nodes    []threadCommentNode `json:"nodes"`
 	} `json:"comments"`
 }
 
@@ -106,14 +113,17 @@ type threadCommentNode struct {
 
 // PRReviewContext fetches everything the diff view needs to draw and change
 // a review. It walks review threads one page at a time itself, since
-// `gh api --paginate` cannot follow a GraphQL cursor below the top level.
+// `gh api --paginate` cannot follow a GraphQL cursor below the top level,
+// and follows a thread's own comments only when that thread says it has
+// more.
 func (c *Client) PRReviewContext(ctx context.Context, repo string, number int) (gh.ReviewContext, error) {
 	repoFields, err := repoArgs(c.effectiveRepo(repo))
 	if err != nil {
 		return gh.ReviewContext{}, err
 	}
 
 	var rc gh.ReviewContext
+	var nodes []threadNode
 	cursor := ""
 	for {
 		args := append([]string{"api", "graphql", "-f", "query=" + reviewContextQuery}, repoFields...)
@@ -142,15 +152,66 @@ func (c *Client) PRReviewContext(ctx context.Context, repo string, number int) (
 		if len(pr.Reviews.Nodes) > 0 {
 			rc.PendingID = pr.Reviews.Nodes[0].ID
 		}
-		for _, n := range pr.ReviewThreads.Nodes {
-			rc.Threads = append(rc.Threads, n.toDomain())
-		}
+		nodes = append(nodes, pr.ReviewThreads.Nodes...)
 
 		if !pr.ReviewThreads.PageInfo.HasNextPage || pr.ReviewThreads.PageInfo.EndCursor == "" {
-			return rc, nil
+			break
 		}
 		cursor = pr.ReviewThreads.PageInfo.EndCursor
 	}
+
+	for _, n := range nodes {
+		t := n.toDomain()
+		if n.Comments.PageInfo.HasNextPage && n.Comments.PageInfo.EndCursor != "" {
+			rest, err := c.threadComments(ctx, n.ID, n.Comments.PageInfo.EndCursor)
+			if err != nil {
+				return gh.ReviewContext{}, fmt.Errorf("fetch thread comments: %w", err)
+			}
+			t.Comments = append(t.Comments, rest...)
+		}
+		rc.Threads = append(rc.Threads, t)
+	}
+	return rc, nil
+}
+
+type threadCommentsResponse struct {
+	Data struct {
+		Node struct {
+			Comments struct {
+				PageInfo pageInfo            `json:"pageInfo"`
+				Nodes    []threadCommentNode `json:"nodes"`
+			} `json:"comments"`
+		} `json:"node"`
+	} `json:"data"`
+}
+
+// threadComments reads what did not fit in the page PRReviewContext already
+// has, starting after the cursor that page ended on.
+func (c *Client) threadComments(ctx context.Context, threadID, after string) ([]gh.ThreadComment, error) {
+	var rest []gh.ThreadComment
+	cursor := after
+	for {
+		args := []string{
+			"api", "graphql", "-f", "query=" + threadCommentsQuery,
+			"-f", "threadId=" + threadID, "-f", "after=" + cursor,
+		}
+		out, err := c.run(ctx, c.dir, args...)
+		if err != nil {
+			return nil, err
+		}
+		var resp threadCommentsResponse
+		if err := json.Unmarshal(out, &resp); err != nil {
+			return nil, fmt.Errorf("parse thread comments: %w", err)
+		}
+		page := resp.Data.Node.Comments
+		for _, n := range page.Nodes {
+			rest = append(rest, n.toDomain())
+		}
+		if !page.PageInfo.HasNextPage || page.PageInfo.EndCursor == "" {
+			return rest, nil
+		}
+		cursor = page.PageInfo.EndCursor
+	}
 }
 
 func (n threadNode) toDomain() gh.ReviewThread {
@@ -167,18 +228,22 @@ func (n threadNode) toDomain() gh.ReviewThread {
 		t.Side = gh.SideLeft
 	}
 	for _, c := range n.Comments.Nodes {
-		t.Comments = append(t.Comments, gh.ThreadComment{
-			Author:    gh.Author{Login: c.Author.Login},
-			Body:      c.Body,
-			CreatedAt: c.CreatedAt,
-			// PENDING is the only review state that means "written but not
-			// sent"; every other one means the comment is already public.
-			Pending: c.PullRequestReview.State == "PENDING",
-		})
+		t.Comments = append(t.Comments, c.toDomain())
 	}
 	return t
 }
 
+func (c threadCommentNode) toDomain() gh.ThreadComment {
+	return gh.ThreadComment{
+		Author:    gh.Author{Login: c.Author.Login},
+		Body:      c.Body,
+		CreatedAt: c.CreatedAt,
+		// PENDING is the only review state that means "written but not
+		// sent"; every other one means the comment is already public.
+		Pending: c.PullRequestReview.State == "PENDING",
+	}
+}
+
 // The five mutations take no context. They are changes, not fetches: a
 // comment that has been sent has been sent, so there is nothing to abandon
 // half-way. The existing AddPRComment and ClosePR take none for the same

internal/gh/cli/review.graphql

@@ -27,15 +27,21 @@ query ($owner: String!, $name: String!, $number: Int!, $after: String) {
           endCursor
         }
         nodes {
+          id
           isResolved
           isOutdated
           path
           line
           originalLine
           diffSide
-          # Not paged: it is a nested connection, so following it would need
-          # one more request per thread.
+          # A nested connection: following it costs one more request per
+          # thread, so only a thread that says hasNextPage gets one
+          # (thread_comments.graphql).
           comments(first: 50) {
+            pageInfo {
+              hasNextPage
+              endCursor
+            }
             nodes {
               body
               createdAt

internal/gh/cli/review_test.go

@@ -443,3 +443,100 @@ func TestPRReviewContextWalksEveryPageOfThreads(t *testing.T) {
 		t.Errorf("first call = %v, want no cursor", f.calls[0])
 	}
 }
+
+// GitHub caps a thread's comments at what the first page asked for; without
+// a second request the rest of a long conversation vanishes with no error.
+func TestPRReviewContextWalksEveryPageOfAThreadsComments(t *testing.T) {
+	t.Parallel()
+
+	threads := `{"data":{"repository":{"pullRequest":{"id":"PR_1",` +
+		`"reviewThreads":{"pageInfo":{"hasNextPage":false,"endCursor":"T1"},` +
+		`"nodes":[{"id":"THREAD_1","path":"a.go","originalLine":1,"diffSide":"RIGHT",` +
+		`"comments":{"pageInfo":{"hasNextPage":true,"endCursor":"C50"},` +
+		`"nodes":[{"body":"first","author":{"login":"kukv"}}]}}]}}}}}`
+	rest := `{"data":{"node":{"comments":{"pageInfo":{"hasNextPage":false,"endCursor":"C99"},` +
+		`"nodes":[{"body":"fifty-first","author":{"login":"kukv"}}]}}}}`
+
+	f := &fakeSeq{outs: []string{threads, rest}}
+	c := &Client{dir: "/repo", repo: "kukv/octoscope", run: f.run}
+
+	rc, err := c.PRReviewContext(t.Context(), "", 55)
+	if err != nil {
+		t.Fatalf("PRReviewContext: %v", err)
+	}
+	if len(f.calls) != 2 {
+		t.Fatalf("calls = %d, want 2 (the thread says it has more comments)", len(f.calls))
+	}
+	if !slices.Contains(f.calls[1], "threadId=THREAD_1") {
+		t.Errorf("second call = %v, want it to name the thread", f.calls[1])
+	}
+	// Without the cursor the second request asks for the first fifty again
+	// and the loop never ends.
+	if !slices.Contains(f.calls[1], "after=C50") {
+		t.Errorf("second call = %v, want it to carry after=C50", f.calls[1])
+	}
+	if len(rc.Threads) != 1 {
+		t.Fatalf("Threads = %d, want 1", len(rc.Threads))
+	}
+	got := rc.Threads[0].Comments
+	if len(got) != 2 {
+		t.Fatalf("Comments = %d, want 2 (one from each page)", len(got))
+	}
+	if got[0].Body != "first" || got[1].Body != "fifty-first" {
+		t.Errorf("Comments = %q / %q, want the second page appended after the first",
+			got[0].Body, got[1].Body)
+	}
+}
+
+func TestAThreadThatFitsInOnePageCostsNoExtraRequest(t *testing.T) {
+	t.Parallel()
+
+	threads := `{"data":{"repository":{"pullRequest":{"id":"PR_1",` +
+		`"reviewThreads":{"pageInfo":{"hasNextPage":false,"endCursor":"T1"},` +
+		`"nodes":[{"id":"THREAD_1","path":"a.go","originalLine":1,"diffSide":"RIGHT",` +
+		`"comments":{"pageInfo":{"hasNextPage":false,"endCursor":"C1"},` +
+		`"nodes":[{"body":"only","author":{"login":"kukv"}}]}}]}}}}}`
+
+	f := &fakeSeq{outs: []string{threads}}
+	c := &Client{dir: "/repo", repo: "kukv/octoscope", run: f.run}
+
+	if _, err := c.PRReviewContext(t.Context(), "", 55); err != nil {
+		t.Fatalf("PRReviewContext: %v", err)
+	}
+	if len(f.calls) != 1 {
+		t.Errorf("calls = %d, want 1: a thread with nothing more must not cost a request", len(f.calls))
+	}
+}
+
+func TestAThreadWithThreePagesOfCommentsIsFollowedToTheEnd(t *testing.T) {
+	t.Parallel()
+
+	threads := `{"data":{"repository":{"pullRequest":{"id":"PR_1",` +
+		`"reviewThreads":{"pageInfo":{"hasNextPage":false,"endCursor":"T1"},` +
+		`"nodes":[{"id":"THREAD_1","path":"a.go","originalLine":1,"diffSide":"RIGHT",` +
+		`"comments":{"pageInfo":{"hasNextPage":true,"endCursor":"C50"},` +
+		`"nodes":[{"body":"one","author":{"login":"kukv"}}]}}]}}}}}`
+	page2 := `{"data":{"node":{"comments":{"pageInfo":{"hasNextPage":true,"endCursor":"C150"},` +
+		`"nodes":[{"body":"two","author":{"login":"kukv"}}]}}}}`
+	page3 := `{"data":{"node":{"comments":{"pageInfo":{"hasNextPage":false,"endCursor":"C250"},` +
+		`"nodes":[{"body":"three","author":{"login":"kukv"}}]}}}}`
+
+	f := &fakeSeq{outs: []string{threads, page2, page3}}
+	c := &Client{dir: "/repo", repo: "kukv/octoscope", run: f.run}
+
+	rc, err := c.PRReviewContext(t.Context(), "", 55)
+	if err != nil {
+		t.Fatalf("PRReviewContext: %v", err)
+	}
+	if len(f.calls) != 3 {
+		t.Fatalf("calls = %d, want 3: no cap is placed on the number of pages", len(f.calls))
+	}
+	// Without carrying the cursor forward the third call would repeat
+	// after=C50 and the walk would loop on the same page forever.
+	if !slices.Contains(f.calls[2], "after=C150") {
+		t.Errorf("third call = %v, want it to carry after=C150", f.calls[2])
+	}
+	if len(rc.Threads[0].Comments) != 3 {
+		t.Errorf("Comments = %d, want 3", len(rc.Threads[0].Comments))
+	}
+}

internal/gh/cli/schema_test.go

@@ -40,15 +40,16 @@ func TestEveryFieldTheDocumentsSelectExistsInTheSchema(t *testing.T) {
 	t.Parallel()
 
 	docs := map[string]string{
-		"work.graphql":           workQuery,
-		"review.graphql":         reviewContextQuery,
-		"start_review.graphql":   startReviewMutation,
-		"add_thread.graphql":     addThreadMutation,
-		"submit_review.graphql":  submitReviewMutation,
-		"review_at_once.graphql": reviewAtOnceMutation,
-		"discard_review.graphql": discardReviewMutation,
-		"checks.graphql":         checksQuery,
-		"merge.graphql":          mergeContextQuery,
+		"work.graphql":            workQuery,
+		"review.graphql":          reviewContextQuery,
+		"start_review.graphql":    startReviewMutation,
+		"add_thread.graphql":      addThreadMutation,
+		"submit_review.graphql":   submitReviewMutation,
+		"review_at_once.graphql":  reviewAtOnceMutation,
+		"discard_review.graphql":  discardReviewMutation,
+		"thread_comments.graphql": threadCommentsQuery,
+		"checks.graphql":          checksQuery,
+		"merge.graphql":           mergeContextQuery,
 
 		"merge_pr.graphql":           mergePRMutation,
 		"enable_auto_merge.graphql":  enableAutoMergeMutation,

internal/gh/cli/testdata/README.md

@@ -116,7 +116,7 @@ def named: if .name != null then .name else (.ofType | named) end;
 | from_entries
 JQ
 
-jq --argjson types '["Query","Mutation","Repository","PullRequest","Issue","Actor","Label","LabelConnection","PullRequestReviewConnection","PullRequestReview","PullRequestReviewThreadConnection","PullRequestReviewThread","PullRequestReviewCommentConnection","PullRequestReviewComment","SearchResultItemConnection","SearchResultItem","PullRequestCommitConnection","PullRequestCommit","Commit","StatusCheckRollup","StatusCheckRollupContextConnection","StatusCheckRollupContext","CheckRun","StatusContext","CheckSuite","WorkflowRun","Workflow","AddPullRequestReviewPayload","AddPullRequestReviewThreadPayload","SubmitPullRequestReviewPayload","DeletePullRequestReviewPayload","PageInfo","AutoMergeRequest","MergePullRequestPayload","EnablePullRequestAutoMergePayload","DisablePullRequestAutoMergePayload"]' \
+jq --argjson types '["Query","Mutation","Repository","PullRequest","Issue","Actor","Label","LabelConnection","PullRequestReviewConnection","PullRequestReview","PullRequestReviewThreadConnection","PullRequestReviewThread","PullRequestReviewCommentConnection","PullRequestReviewComment","SearchResultItemConnection","SearchResultItem","PullRequestCommitConnection","PullRequestCommit","Commit","StatusCheckRollup","StatusCheckRollupContextConnection","StatusCheckRollupContext","CheckRun","StatusContext","CheckSuite","WorkflowRun","Workflow","AddPullRequestReviewPayload","AddPullRequestReviewThreadPayload","SubmitPullRequestReviewPayload","DeletePullRequestReviewPayload","Node","PageInfo","AutoMergeRequest","MergePullRequestPayload","EnablePullRequestAutoMergePayload","DisablePullRequestAutoMergePayload"]' \
   -f /tmp/trim.jq /tmp/schema-full.json > internal/gh/cli/testdata/schema.json
 ```