fix: address review feedback on PR #102

- Separate maxPages into maxFilesPages and maxCheckRunPages constants
  for clarity (sonnet MINOR #1)
- Add parallel to CheckRunConclusions subtests (sonnet MINOR #2)
- Add TestGetCommitStatuses_CheckRunsErrorAfterStatusesSucceed test
  covering check-runs 500 after statuses succeed (sonnet MINOR #2)
- Expand mapCheckRunStatus doc comment with full mapping rules including
  cancelled/skipped/neutral rationale and unknown value behavior
  (sonnet MINOR #3, gpt MINOR #1)
- Expand GetPullRequest doc comment to mention error types returned
  (sonnet NIT #4)
- Add inline comment on Description field clarifying it holds raw
  conclusion value (gpt NIT #3)

github/pr_test.go

@@ -545,6 +545,7 @@ func TestGetCommitStatuses_CheckRunConclusions(t *testing.T) {
 			name = *tt.conclusion
 		}
 		t.Run(name, func(t *testing.T) {
+			t.Parallel()
 			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 				if strings.Contains(r.URL.Path, "/status") {
 					json.NewEncoder(w).Encode(map[string]interface{}{
@@ -632,6 +633,44 @@ func TestGetCommitStatuses_MalformedJSON(t *testing.T) {
 	}
 }
 
+func TestGetCommitStatuses_CheckRunsErrorAfterStatusesSucceed(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.Contains(r.URL.Path, "/status"):
+			// Statuses succeed
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"state": "success",
+				"statuses": []map[string]string{
+					{
+						"context":     "ci/build",
+						"state":       "success",
+						"description": "Build passed",
+						"target_url":  "https://ci.example.com/1",
+					},
+				},
+			})
+		case strings.Contains(r.URL.Path, "/check-runs"):
+			// Check runs fail with 500
+			w.WriteHeader(500)
+			w.Write([]byte(`{"message":"Internal Server Error"}`))
+		default:
+			w.WriteHeader(404)
+		}
+	}))
+	defer srv.Close()
+
+	c := NewClient("token", srv.URL, AllowInsecureHTTP())
+	c.SetHTTPClient(srv.Client())
+
+	_, err := c.GetCommitStatuses(context.Background(), "owner", "repo", "abc123")
+	if err == nil {
+		t.Fatal("expected error when check-runs endpoint fails after statuses succeed")
+	}
+	if !strings.Contains(err.Error(), "fetch check runs") {
+		t.Errorf("expected check runs error, got: %v", err)
+	}
+}
+
 func stringPtr(s string) *string {
 	return &s
 }