fix(github): add pagination tests and fix truncation warning logic

F1: Add comprehensive pagination tests for ListReviews covering:
- Multi-page behaviour (2 full + 1 partial page)
- Exact-multiple-of-pageSize (extra empty-page round-trip)
- maxReviewPages cutoff (cap hit, results still returned)
- Empty first page (PR with no reviews)

F2: Fix truncation warning logic by moving it outside the loop with
a 'truncated' flag. Previously, the warning fired inline at page==maxPages
which could miss the case where the short-page break fires first on the
cap page. Now it only fires when the loop exits because the cap was reached
and the last page was full (indicating more data likely exists).

Also adds SetReviewPagination to Client for test-time override of page
size and max pages, following the existing SetRetryBackoff pattern.

github/client.go

@@ -110,6 +110,11 @@ type Client struct {
 	// retryBackoff[i] is the delay before attempt i+1 (after attempt i fails).
 	// If nil, defaults to {1s, 2s}. Set to shorter durations in tests via SetRetryBackoff.
 	retryBackoff []time.Duration
+
+	// reviewPageSize overrides reviewsPerPage for testing. Zero means use default.
+	reviewPageSize int
+	// reviewMaxPages overrides maxReviewPages for testing. Zero means use default.
+	reviewMaxPages int
 }
 
 // defaultCheckRedirect is the redirect policy used by NewClient and SetHTTPClient(nil).
@@ -194,6 +199,13 @@ func (c *Client) SetRetryBackoff(d []time.Duration) error {
 	return nil
 }
 
+// SetReviewPagination overrides the page size and max pages for ListReviews.
+// Intended for testing only; must be called before any goroutines issue requests.
+func (c *Client) SetReviewPagination(pageSize, maxPages int) {
+	c.reviewPageSize = pageSize
+	c.reviewMaxPages = maxPages
+}
+
 // requestOptions holds per-request configuration for doRequestCore.
 type requestOptions struct {
 	// bodyFn returns a fresh io.Reader for the request body on each attempt.

github/review_test.go

@@ -2,6 +2,7 @@ package github
 
 import (
 	"context"
+	"fmt"
 	"encoding/json"
 	"errors"
 	"io"
@@ -482,3 +483,195 @@ func TestPostReview_RequestCommitID_FallbackToComment(t *testing.T) {
 		t.Errorf("sent commit_id = %q, want %q (fallback from comment)", gotPayload.CommitID, "comment-sha")
 	}
 }
+
+// --- ListReviews pagination tests ---
+
+func TestListReviews_MultiPage(t *testing.T) {
+	// Test multi-page pagination: 2 full pages + 1 partial page.
+	// pageSize=3, so pages return [3, 3, 2] reviews = 8 total.
+	const pageSize = 3
+	callCount := 0
+
+	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "GET" {
+			t.Fatalf("expected GET, got %s", r.Method)
+		}
+		callCount++
+
+		page := r.URL.Query().Get("page")
+		var reviews []map[string]interface{}
+
+		switch page {
+		case "1":
+			for i := 1; i <= pageSize; i++ {
+				reviews = append(reviews, map[string]interface{}{
+					"id": i, "body": fmt.Sprintf("review %d", i),
+					"state": "APPROVED", "commit_id": "sha1",
+					"user": map[string]string{"login": "user1"},
+				})
+			}
+		case "2":
+			for i := pageSize + 1; i <= pageSize*2; i++ {
+				reviews = append(reviews, map[string]interface{}{
+					"id": i, "body": fmt.Sprintf("review %d", i),
+					"state": "COMMENTED", "commit_id": "sha1",
+					"user": map[string]string{"login": "user2"},
+				})
+			}
+		case "3":
+			// Partial page: only 2 reviews (less than pageSize)
+			for i := pageSize*2 + 1; i <= pageSize*2+2; i++ {
+				reviews = append(reviews, map[string]interface{}{
+					"id": i, "body": fmt.Sprintf("review %d", i),
+					"state": "CHANGES_REQUESTED", "commit_id": "sha1",
+					"user": map[string]string{"login": "user3"},
+				})
+			}
+		default:
+			t.Fatalf("unexpected page: %s", page)
+		}
+
+		json.NewEncoder(w).Encode(reviews)
+	})
+	c.SetReviewPagination(pageSize, 10)
+
+	reviews, err := c.ListReviews(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 8 {
+		t.Fatalf("expected 8 reviews, got %d", len(reviews))
+	}
+	if callCount != 3 {
+		t.Errorf("expected 3 API calls, got %d", callCount)
+	}
+
+	// Verify reviews are correctly concatenated in order
+	for i, r := range reviews {
+		expectedID := int64(i + 1)
+		if r.ID != expectedID {
+			t.Errorf("review[%d]: expected ID %d, got %d", i, expectedID, r.ID)
+		}
+	}
+}
+
+func TestListReviews_ExactMultipleOfPageSize(t *testing.T) {
+	// When total reviews is an exact multiple of pageSize, an extra request
+	// returning 0 results terminates the loop. No truncation warning.
+	const pageSize = 2
+	callCount := 0
+
+	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
+		callCount++
+		page := r.URL.Query().Get("page")
+
+		var reviews []map[string]interface{}
+		switch page {
+		case "1":
+			reviews = []map[string]interface{}{
+				{"id": 1, "body": "r1", "state": "APPROVED", "commit_id": "s1", "user": map[string]string{"login": "u1"}},
+				{"id": 2, "body": "r2", "state": "APPROVED", "commit_id": "s1", "user": map[string]string{"login": "u2"}},
+			}
+		case "2":
+			reviews = []map[string]interface{}{
+				{"id": 3, "body": "r3", "state": "APPROVED", "commit_id": "s1", "user": map[string]string{"login": "u3"}},
+				{"id": 4, "body": "r4", "state": "APPROVED", "commit_id": "s1", "user": map[string]string{"login": "u4"}},
+			}
+		case "3":
+			// Empty page — signals end of data
+			reviews = []map[string]interface{}{}
+		default:
+			t.Fatalf("unexpected page: %s", page)
+		}
+
+		json.NewEncoder(w).Encode(reviews)
+	})
+	c.SetReviewPagination(pageSize, 10)
+
+	reviews, err := c.ListReviews(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 4 {
+		t.Fatalf("expected 4 reviews, got %d", len(reviews))
+	}
+	// 3 calls: page 1 (full), page 2 (full), page 3 (empty)
+	if callCount != 3 {
+		t.Errorf("expected 3 API calls, got %d", callCount)
+	}
+}
+
+func TestListReviews_MaxPagesCutoff(t *testing.T) {
+	// When maxPages is hit and the last page is full, results are truncated
+	// and a warning would fire (we verify the reviews are still returned).
+	const pageSize = 2
+	const maxPages = 2
+	callCount := 0
+
+	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
+		callCount++
+		page := r.URL.Query().Get("page")
+
+		// Always return a full page (simulating more data exists)
+		var reviews []map[string]interface{}
+		var baseID int
+		switch page {
+		case "1":
+			baseID = 0
+		case "2":
+			baseID = pageSize
+		default:
+			t.Fatalf("unexpected page %s (should not exceed maxPages)", page)
+		}
+		for i := 1; i <= pageSize; i++ {
+			reviews = append(reviews, map[string]interface{}{
+				"id": baseID + i, "body": fmt.Sprintf("r%d", baseID+i),
+				"state": "APPROVED", "commit_id": "sha1",
+				"user": map[string]string{"login": "user"},
+			})
+		}
+
+		json.NewEncoder(w).Encode(reviews)
+	})
+	c.SetReviewPagination(pageSize, maxPages)
+
+	reviews, err := c.ListReviews(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	// Should return all reviews fetched within the cap
+	expectedCount := pageSize * maxPages
+	if len(reviews) != expectedCount {
+		t.Fatalf("expected %d reviews, got %d", expectedCount, len(reviews))
+	}
+	if callCount != maxPages {
+		t.Errorf("expected %d API calls, got %d", maxPages, callCount)
+	}
+	// Verify concatenation order
+	for i, r := range reviews {
+		if r.ID != int64(i+1) {
+			t.Errorf("review[%d]: expected ID %d, got %d", i, i+1, r.ID)
+		}
+	}
+}
+
+func TestListReviews_EmptyFirstPage(t *testing.T) {
+	// PR with no reviews: first page returns empty array.
+	callCount := 0
+	c := newTestClient(t, func(w http.ResponseWriter, r *http.Request) {
+		callCount++
+		json.NewEncoder(w).Encode([]map[string]interface{}{})
+	})
+	c.SetReviewPagination(10, 5)
+
+	reviews, err := c.ListReviews(context.Background(), "owner", "repo", 1)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 0 {
+		t.Fatalf("expected 0 reviews, got %d", len(reviews))
+	}
+	if callCount != 1 {
+		t.Errorf("expected 1 API call, got %d", callCount)
+	}
+}

github/reviews.go

@@ -153,11 +153,21 @@ func (c *Client) PostReview(ctx context.Context, owner, repo string, number int,
 // ListReviews retrieves all reviews for a pull request with pagination.
 // GitHub review states are translated to canonical vcs values.
 func (c *Client) ListReviews(ctx context.Context, owner, repo string, number int) ([]vcs.Review, error) {
-	var allReviews []vcs.Review
+	perPage := reviewsPerPage
+	if c.reviewPageSize > 0 {
+		perPage = c.reviewPageSize
+	}
+	maxPages := maxReviewPages
+	if c.reviewMaxPages > 0 {
+		maxPages = c.reviewMaxPages
+	}
 
-	for page := 1; page <= maxReviewPages; page++ {
+	var allReviews []vcs.Review
+	truncated := false
+
+	for page := 1; page <= maxPages; page++ {
 		reqURL := fmt.Sprintf("%s/repos/%s/%s/pulls/%d/reviews?per_page=%d&page=%d",
-			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number, reviewsPerPage, page)
+			c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number, perPage, page)
 
 		body, err := c.doGet(ctx, reqURL)
 		if err != nil {
@@ -183,17 +193,23 @@ func (c *Client) ListReviews(ctx context.Context, owner, repo string, number int
 			})
 		}
 
-		if len(responses) < reviewsPerPage {
+		if len(responses) < perPage {
 			break
 		}
 
-		if page == maxReviewPages {
+		// If we just fetched page maxPages and it was full (the short-page break
-			slog.Warn("ListReviews hit page limit; results may be truncated",
+		// above didn't fire), more reviews likely exist beyond our limit.
-				"owner", owner, "repo", repo, "pr", number,
+		if page == maxPages {
-				"maxPages", maxReviewPages, "reviewsFetched", len(allReviews))
+			truncated = true
 		}
 	}
 
+	if truncated {
+		slog.Warn("ListReviews hit page limit; results may be truncated",
+			"owner", owner, "repo", repo, "pr", number,
+			"maxPages", maxPages, "reviewsFetched", len(allReviews))
+	}
+
 	return allReviews, nil
 }