feat: add time-based comment filtering to tag mode (#512)

Implement time-based filtering for GitHub comments and reviews to prevent
malicious actors from editing existing comments after Claude is triggered
to inject harmful content.

Changes:
- Add updatedAt and lastEditedAt fields to GraphQL queries
- Update GitHubComment and GitHubReview types with timestamp fields
- Implement filterCommentsToTriggerTime() and filterReviewsToTriggerTime()
- Add extractTriggerTimestamp() to extract trigger time from webhooks
- Update tag and review modes to pass trigger timestamp to data fetcher

Security benefits:
- Prevents comment injection attacks via post-trigger edits
- Maintains chronological integrity of conversation context
- Ensures only comments in their final state before trigger are processed
- Backward compatible with graceful degradation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

src/github/data/fetcher.ts

@@ -48,7 +48,7 @@ export function extractTriggerTimestamp(
  * @param triggerTime - ISO timestamp of when the trigger comment was created
  * @returns Filtered array of comments that were created and last edited before trigger time
  */
-function filterCommentsToTriggerTime<
+export function filterCommentsToTriggerTime<
   T extends { createdAt: string; updatedAt?: string; lastEditedAt?: string },
 >(comments: T[], triggerTime: string | undefined): T[] {
   if (!triggerTime) return comments;
@@ -56,10 +56,9 @@ function filterCommentsToTriggerTime<
   const triggerTimestamp = new Date(triggerTime).getTime();
 
   return comments.filter((comment) => {
-    // Comment must have been created before trigger
+    // Comment must have been created before trigger (not at or after)
     const createdTimestamp = new Date(comment.createdAt).getTime();
-    if (createdTimestamp > triggerTimestamp) {
+    if (createdTimestamp >= triggerTimestamp) {
-      console.log("filtering for creation time", comment);
       return false;
     }
 
@@ -68,8 +67,7 @@ function filterCommentsToTriggerTime<
     const lastEditTime = comment.lastEditedAt || comment.updatedAt;
     if (lastEditTime) {
       const lastEditTimestamp = new Date(lastEditTime).getTime();
-      if (lastEditTimestamp > triggerTimestamp) {
+      if (lastEditTimestamp >= triggerTimestamp) {
-        console.log("filtering for last edit time", comment);
         return false;
       }
     }
@@ -82,7 +80,7 @@ function filterCommentsToTriggerTime<
  * Filters reviews to only include those that existed in their final state before the trigger time.
  * Similar to filterCommentsToTriggerTime but for GitHubReview objects which use submittedAt instead of createdAt.
  */
-function filterReviewsToTriggerTime<
+export function filterReviewsToTriggerTime<
   T extends { submittedAt: string; updatedAt?: string; lastEditedAt?: string },
 >(reviews: T[], triggerTime: string | undefined): T[] {
   if (!triggerTime) return reviews;
@@ -90,9 +88,9 @@ function filterReviewsToTriggerTime<
   const triggerTimestamp = new Date(triggerTime).getTime();
 
   return reviews.filter((review) => {
-    // Review must have been submitted before trigger
+    // Review must have been submitted before trigger (not at or after)
     const submittedTimestamp = new Date(review.submittedAt).getTime();
-    if (submittedTimestamp > triggerTimestamp) {
+    if (submittedTimestamp >= triggerTimestamp) {
       return false;
     }
 
@@ -100,7 +98,7 @@ function filterReviewsToTriggerTime<
     const lastEditTime = review.lastEditedAt || review.updatedAt;
     if (lastEditTime) {
       const lastEditTimestamp = new Date(lastEditTime).getTime();
-      if (lastEditTimestamp > triggerTimestamp) {
+      if (lastEditTimestamp >= triggerTimestamp) {
         return false;
       }
     }

test/data-fetcher.test.ts

@@ -0,0 +1,699 @@
+import { describe, expect, it, jest } from "bun:test";
+import {
+  extractTriggerTimestamp,
+  fetchGitHubData,
+  filterCommentsToTriggerTime,
+  filterReviewsToTriggerTime,
+} from "../src/github/data/fetcher";
+import {
+  createMockContext,
+  mockIssueCommentContext,
+  mockPullRequestReviewContext,
+  mockPullRequestReviewCommentContext,
+  mockPullRequestOpenedContext,
+  mockIssueOpenedContext,
+} from "./mockContext";
+import type { GitHubComment, GitHubReview } from "../src/github/types";
+
+describe("extractTriggerTimestamp", () => {
+  it("should extract timestamp from IssueCommentEvent", () => {
+    const context = mockIssueCommentContext;
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBe("2024-01-15T12:30:00Z");
+  });
+
+  it("should extract timestamp from PullRequestReviewEvent", () => {
+    const context = mockPullRequestReviewContext;
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBe("2024-01-15T15:30:00Z");
+  });
+
+  it("should extract timestamp from PullRequestReviewCommentEvent", () => {
+    const context = mockPullRequestReviewCommentContext;
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBe("2024-01-15T16:45:00Z");
+  });
+
+  it("should return undefined for pull_request event", () => {
+    const context = mockPullRequestOpenedContext;
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBeUndefined();
+  });
+
+  it("should return undefined for issues event", () => {
+    const context = mockIssueOpenedContext;
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBeUndefined();
+  });
+
+  it("should handle missing timestamp fields gracefully", () => {
+    const context = createMockContext({
+      eventName: "issue_comment",
+      payload: {
+        comment: {
+          // No created_at field
+          id: 123,
+          body: "test",
+        },
+      } as any,
+    });
+    const timestamp = extractTriggerTimestamp(context);
+    expect(timestamp).toBeUndefined();
+  });
+});
+
+describe("filterCommentsToTriggerTime", () => {
+  const createMockComment = (
+    createdAt: string,
+    updatedAt?: string,
+    lastEditedAt?: string,
+  ): GitHubComment => ({
+    id: String(Math.random()),
+    databaseId: String(Math.random()),
+    body: "Test comment",
+    author: { login: "test-user" },
+    createdAt,
+    updatedAt,
+    lastEditedAt,
+    isMinimized: false,
+  });
+
+  const triggerTime = "2024-01-15T12:00:00Z";
+
+  describe("comment creation time filtering", () => {
+    it("should include comments created before trigger time", () => {
+      const comments = [
+        createMockComment("2024-01-15T11:00:00Z"),
+        createMockComment("2024-01-15T11:30:00Z"),
+        createMockComment("2024-01-15T11:59:59Z"),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(comments);
+    });
+
+    it("should exclude comments created after trigger time", () => {
+      const comments = [
+        createMockComment("2024-01-15T12:00:01Z"),
+        createMockComment("2024-01-15T13:00:00Z"),
+        createMockComment("2024-01-16T00:00:00Z"),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+
+    it("should handle exact timestamp match (at trigger time)", () => {
+      const comment = createMockComment("2024-01-15T12:00:00Z");
+      const filtered = filterCommentsToTriggerTime([comment], triggerTime);
+      // Comments created exactly at trigger time should be excluded for security
+      expect(filtered.length).toBe(0);
+    });
+  });
+
+  describe("comment edit time filtering", () => {
+    it("should include comments edited before trigger time", () => {
+      const comments = [
+        createMockComment("2024-01-15T10:00:00Z", "2024-01-15T11:00:00Z"),
+        createMockComment(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T11:30:00Z",
+        ),
+        createMockComment(
+          "2024-01-15T10:00:00Z",
+          "2024-01-15T11:00:00Z",
+          "2024-01-15T11:30:00Z",
+        ),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(comments);
+    });
+
+    it("should exclude comments edited after trigger time", () => {
+      const comments = [
+        createMockComment("2024-01-15T10:00:00Z", "2024-01-15T13:00:00Z"),
+        createMockComment(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T13:00:00Z",
+        ),
+        createMockComment(
+          "2024-01-15T10:00:00Z",
+          "2024-01-15T11:00:00Z",
+          "2024-01-15T13:00:00Z",
+        ),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+
+    it("should prioritize lastEditedAt over updatedAt", () => {
+      const comment = createMockComment(
+        "2024-01-15T10:00:00Z",
+        "2024-01-15T13:00:00Z", // updatedAt after trigger
+        "2024-01-15T11:00:00Z", // lastEditedAt before trigger
+      );
+
+      const filtered = filterCommentsToTriggerTime([comment], triggerTime);
+      // lastEditedAt takes precedence, so this should be included
+      expect(filtered.length).toBe(1);
+      expect(filtered[0]).toBe(comment);
+    });
+
+    it("should handle comments without edit timestamps", () => {
+      const comment = createMockComment("2024-01-15T10:00:00Z");
+      expect(comment.updatedAt).toBeUndefined();
+      expect(comment.lastEditedAt).toBeUndefined();
+
+      const filtered = filterCommentsToTriggerTime([comment], triggerTime);
+      expect(filtered.length).toBe(1);
+      expect(filtered[0]).toBe(comment);
+    });
+
+    it("should exclude comments edited exactly at trigger time", () => {
+      const comments = [
+        createMockComment("2024-01-15T10:00:00Z", "2024-01-15T12:00:00Z"), // updatedAt exactly at trigger
+        createMockComment(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T12:00:00Z",
+        ), // lastEditedAt exactly at trigger
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+  });
+
+  describe("edge cases", () => {
+    it("should return all comments when no trigger time provided", () => {
+      const comments = [
+        createMockComment("2024-01-15T10:00:00Z"),
+        createMockComment("2024-01-15T13:00:00Z"),
+        createMockComment("2024-01-16T00:00:00Z"),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, undefined);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(comments);
+    });
+
+    it("should handle millisecond precision", () => {
+      const comments = [
+        createMockComment("2024-01-15T12:00:00.001Z"), // After trigger by 1ms
+        createMockComment("2024-01-15T11:59:59.999Z"), // Before trigger
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(1);
+      expect(filtered[0]?.createdAt).toBe("2024-01-15T11:59:59.999Z");
+    });
+
+    it("should handle various ISO timestamp formats", () => {
+      const comments = [
+        createMockComment("2024-01-15T11:00:00Z"),
+        createMockComment("2024-01-15T11:00:00.000Z"),
+        createMockComment("2024-01-15T11:00:00+00:00"),
+      ];
+
+      const filtered = filterCommentsToTriggerTime(comments, triggerTime);
+      expect(filtered.length).toBe(3);
+    });
+  });
+});
+
+describe("filterReviewsToTriggerTime", () => {
+  const createMockReview = (
+    submittedAt: string,
+    updatedAt?: string,
+    lastEditedAt?: string,
+  ): GitHubReview => ({
+    id: String(Math.random()),
+    databaseId: String(Math.random()),
+    author: { login: "reviewer" },
+    body: "Test review",
+    state: "APPROVED",
+    submittedAt,
+    updatedAt,
+    lastEditedAt,
+    comments: { nodes: [] },
+  });
+
+  const triggerTime = "2024-01-15T12:00:00Z";
+
+  describe("review submission time filtering", () => {
+    it("should include reviews submitted before trigger time", () => {
+      const reviews = [
+        createMockReview("2024-01-15T11:00:00Z"),
+        createMockReview("2024-01-15T11:30:00Z"),
+        createMockReview("2024-01-15T11:59:59Z"),
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, triggerTime);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(reviews);
+    });
+
+    it("should exclude reviews submitted after trigger time", () => {
+      const reviews = [
+        createMockReview("2024-01-15T12:00:01Z"),
+        createMockReview("2024-01-15T13:00:00Z"),
+        createMockReview("2024-01-16T00:00:00Z"),
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+
+    it("should handle exact timestamp match", () => {
+      const review = createMockReview("2024-01-15T12:00:00Z");
+      const filtered = filterReviewsToTriggerTime([review], triggerTime);
+      // Reviews submitted exactly at trigger time should be excluded for security
+      expect(filtered.length).toBe(0);
+    });
+  });
+
+  describe("review edit time filtering", () => {
+    it("should include reviews edited before trigger time", () => {
+      const reviews = [
+        createMockReview("2024-01-15T10:00:00Z", "2024-01-15T11:00:00Z"),
+        createMockReview(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T11:30:00Z",
+        ),
+        createMockReview(
+          "2024-01-15T10:00:00Z",
+          "2024-01-15T11:00:00Z",
+          "2024-01-15T11:30:00Z",
+        ),
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, triggerTime);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(reviews);
+    });
+
+    it("should exclude reviews edited after trigger time", () => {
+      const reviews = [
+        createMockReview("2024-01-15T10:00:00Z", "2024-01-15T13:00:00Z"),
+        createMockReview(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T13:00:00Z",
+        ),
+        createMockReview(
+          "2024-01-15T10:00:00Z",
+          "2024-01-15T11:00:00Z",
+          "2024-01-15T13:00:00Z",
+        ),
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+
+    it("should prioritize lastEditedAt over updatedAt", () => {
+      const review = createMockReview(
+        "2024-01-15T10:00:00Z",
+        "2024-01-15T13:00:00Z", // updatedAt after trigger
+        "2024-01-15T11:00:00Z", // lastEditedAt before trigger
+      );
+
+      const filtered = filterReviewsToTriggerTime([review], triggerTime);
+      // lastEditedAt takes precedence, so this should be included
+      expect(filtered.length).toBe(1);
+      expect(filtered[0]).toBe(review);
+    });
+
+    it("should handle reviews without edit timestamps", () => {
+      const review = createMockReview("2024-01-15T10:00:00Z");
+      expect(review.updatedAt).toBeUndefined();
+      expect(review.lastEditedAt).toBeUndefined();
+
+      const filtered = filterReviewsToTriggerTime([review], triggerTime);
+      expect(filtered.length).toBe(1);
+      expect(filtered[0]).toBe(review);
+    });
+
+    it("should exclude reviews edited exactly at trigger time", () => {
+      const reviews = [
+        createMockReview("2024-01-15T10:00:00Z", "2024-01-15T12:00:00Z"), // updatedAt exactly at trigger
+        createMockReview(
+          "2024-01-15T10:00:00Z",
+          undefined,
+          "2024-01-15T12:00:00Z",
+        ), // lastEditedAt exactly at trigger
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, triggerTime);
+      expect(filtered.length).toBe(0);
+    });
+  });
+
+  describe("edge cases", () => {
+    it("should return all reviews when no trigger time provided", () => {
+      const reviews = [
+        createMockReview("2024-01-15T10:00:00Z"),
+        createMockReview("2024-01-15T13:00:00Z"),
+        createMockReview("2024-01-16T00:00:00Z"),
+      ];
+
+      const filtered = filterReviewsToTriggerTime(reviews, undefined);
+      expect(filtered.length).toBe(3);
+      expect(filtered).toEqual(reviews);
+    });
+  });
+});
+
+describe("fetchGitHubData integration with time filtering", () => {
+  it("should filter comments based on trigger time when provided", async () => {
+    const mockOctokits = {
+      graphql: jest.fn().mockResolvedValue({
+        repository: {
+          issue: {
+            number: 123,
+            title: "Test Issue",
+            body: "Issue body",
+            author: { login: "author" },
+            comments: {
+              nodes: [
+                {
+                  id: "1",
+                  databaseId: "1",
+                  body: "Comment before trigger",
+                  author: { login: "user1" },
+                  createdAt: "2024-01-15T11:00:00Z",
+                  updatedAt: "2024-01-15T11:00:00Z",
+                },
+                {
+                  id: "2",
+                  databaseId: "2",
+                  body: "Comment after trigger",
+                  author: { login: "user2" },
+                  createdAt: "2024-01-15T13:00:00Z",
+                  updatedAt: "2024-01-15T13:00:00Z",
+                },
+                {
+                  id: "3",
+                  databaseId: "3",
+                  body: "Comment before but edited after",
+                  author: { login: "user3" },
+                  createdAt: "2024-01-15T11:00:00Z",
+                  updatedAt: "2024-01-15T13:00:00Z",
+                  lastEditedAt: "2024-01-15T13:00:00Z",
+                },
+              ],
+            },
+          },
+        },
+        user: { login: "trigger-user" },
+      }),
+      rest: jest.fn() as any,
+    };
+
+    const result = await fetchGitHubData({
+      octokits: mockOctokits as any,
+      repository: "test-owner/test-repo",
+      prNumber: "123",
+      isPR: false,
+      triggerUsername: "trigger-user",
+      triggerTime: "2024-01-15T12:00:00Z",
+    });
+
+    // Should only include the comment created before trigger time
+    expect(result.comments.length).toBe(1);
+    expect(result.comments[0]?.id).toBe("1");
+    expect(result.comments[0]?.body).toBe("Comment before trigger");
+  });
+
+  it("should filter PR reviews based on trigger time", async () => {
+    const mockOctokits = {
+      graphql: jest.fn().mockResolvedValue({
+        repository: {
+          pullRequest: {
+            number: 456,
+            title: "Test PR",
+            body: "PR body",
+            author: { login: "author" },
+            comments: { nodes: [] },
+            files: { nodes: [] },
+            reviews: {
+              nodes: [
+                {
+                  id: "1",
+                  databaseId: "1",
+                  author: { login: "reviewer1" },
+                  body: "Review before trigger",
+                  state: "APPROVED",
+                  submittedAt: "2024-01-15T11:00:00Z",
+                  comments: { nodes: [] },
+                },
+                {
+                  id: "2",
+                  databaseId: "2",
+                  author: { login: "reviewer2" },
+                  body: "Review after trigger",
+                  state: "CHANGES_REQUESTED",
+                  submittedAt: "2024-01-15T13:00:00Z",
+                  comments: { nodes: [] },
+                },
+                {
+                  id: "3",
+                  databaseId: "3",
+                  author: { login: "reviewer3" },
+                  body: "Review before but edited after",
+                  state: "COMMENTED",
+                  submittedAt: "2024-01-15T11:00:00Z",
+                  updatedAt: "2024-01-15T13:00:00Z",
+                  lastEditedAt: "2024-01-15T13:00:00Z",
+                  comments: { nodes: [] },
+                },
+              ],
+            },
+          },
+        },
+        user: { login: "trigger-user" },
+      }),
+      rest: {
+        pulls: {
+          listFiles: jest.fn().mockResolvedValue({ data: [] }),
+        },
+      },
+    };
+
+    const result = await fetchGitHubData({
+      octokits: mockOctokits as any,
+      repository: "test-owner/test-repo",
+      prNumber: "456",
+      isPR: true,
+      triggerUsername: "trigger-user",
+      triggerTime: "2024-01-15T12:00:00Z",
+    });
+
+    // The reviewData field returns all reviews (not filtered), but the filtering
+    // happens when processing review bodies for download
+    // We can check the image download map to verify filtering
+    expect(result.reviewData?.nodes?.length).toBe(3); // All reviews are returned
+
+    // Check that only the first review's body would be downloaded (filtered)
+    const reviewsInMap = Object.keys(result.imageUrlMap).filter((key) =>
+      key.startsWith("review_body"),
+    );
+    // Only review 1 should have its body processed (before trigger and not edited after)
+    expect(reviewsInMap.length).toBeLessThanOrEqual(1);
+  });
+
+  it("should filter review comments based on trigger time", async () => {
+    const mockOctokits = {
+      graphql: jest.fn().mockResolvedValue({
+        repository: {
+          pullRequest: {
+            number: 789,
+            title: "Test PR",
+            body: "PR body",
+            author: { login: "author" },
+            comments: { nodes: [] },
+            files: { nodes: [] },
+            reviews: {
+              nodes: [
+                {
+                  id: "1",
+                  databaseId: "1",
+                  author: { login: "reviewer" },
+                  body: "Review body",
+                  state: "COMMENTED",
+                  submittedAt: "2024-01-15T11:00:00Z",
+                  comments: {
+                    nodes: [
+                      {
+                        id: "10",
+                        databaseId: "10",
+                        body: "Review comment before",
+                        author: { login: "user1" },
+                        createdAt: "2024-01-15T11:30:00Z",
+                      },
+                      {
+                        id: "11",
+                        databaseId: "11",
+                        body: "Review comment after",
+                        author: { login: "user2" },
+                        createdAt: "2024-01-15T12:30:00Z",
+                      },
+                      {
+                        id: "12",
+                        databaseId: "12",
+                        body: "Review comment edited after",
+                        author: { login: "user3" },
+                        createdAt: "2024-01-15T11:30:00Z",
+                        lastEditedAt: "2024-01-15T12:30:00Z",
+                      },
+                    ],
+                  },
+                },
+              ],
+            },
+          },
+        },
+        user: { login: "trigger-user" },
+      }),
+      rest: {
+        pulls: {
+          listFiles: jest.fn().mockResolvedValue({ data: [] }),
+        },
+      },
+    };
+
+    const result = await fetchGitHubData({
+      octokits: mockOctokits as any,
+      repository: "test-owner/test-repo",
+      prNumber: "789",
+      isPR: true,
+      triggerUsername: "trigger-user",
+      triggerTime: "2024-01-15T12:00:00Z",
+    });
+
+    // The imageUrlMap contains processed comments for image downloading
+    // We should have processed review comments, but only those before trigger time
+    // The exact check depends on how imageUrlMap is structured, but we can verify
+    // that filtering occurred by checking the review data still has all nodes
+    expect(result.reviewData?.nodes?.length).toBe(1); // Original review is kept
+
+    // The actual filtering happens during processing for image download
+    // Since the mock doesn't actually download images, we verify the input was correct
+  });
+
+  it("should handle backward compatibility when no trigger time provided", async () => {
+    const mockOctokits = {
+      graphql: jest.fn().mockResolvedValue({
+        repository: {
+          issue: {
+            number: 999,
+            title: "Test Issue",
+            body: "Issue body",
+            author: { login: "author" },
+            comments: {
+              nodes: [
+                {
+                  id: "1",
+                  databaseId: "1",
+                  body: "Old comment",
+                  author: { login: "user1" },
+                  createdAt: "2024-01-15T11:00:00Z",
+                },
+                {
+                  id: "2",
+                  databaseId: "2",
+                  body: "New comment",
+                  author: { login: "user2" },
+                  createdAt: "2024-01-15T13:00:00Z",
+                },
+                {
+                  id: "3",
+                  databaseId: "3",
+                  body: "Edited comment",
+                  author: { login: "user3" },
+                  createdAt: "2024-01-15T11:00:00Z",
+                  lastEditedAt: "2024-01-15T13:00:00Z",
+                },
+              ],
+            },
+          },
+        },
+        user: { login: "trigger-user" },
+      }),
+      rest: jest.fn() as any,
+    };
+
+    const result = await fetchGitHubData({
+      octokits: mockOctokits as any,
+      repository: "test-owner/test-repo",
+      prNumber: "999",
+      isPR: false,
+      triggerUsername: "trigger-user",
+      // No triggerTime provided
+    });
+
+    // Without trigger time, all comments should be included
+    expect(result.comments.length).toBe(3);
+  });
+
+  it("should handle timezone variations in timestamps", async () => {
+    const mockOctokits = {
+      graphql: jest.fn().mockResolvedValue({
+        repository: {
+          issue: {
+            number: 321,
+            title: "Test Issue",
+            body: "Issue body",
+            author: { login: "author" },
+            comments: {
+              nodes: [
+                {
+                  id: "1",
+                  databaseId: "1",
+                  body: "Comment with UTC",
+                  author: { login: "user1" },
+                  createdAt: "2024-01-15T11:00:00Z",
+                },
+                {
+                  id: "2",
+                  databaseId: "2",
+                  body: "Comment with offset",
+                  author: { login: "user2" },
+                  createdAt: "2024-01-15T11:00:00+00:00",
+                },
+                {
+                  id: "3",
+                  databaseId: "3",
+                  body: "Comment with milliseconds",
+                  author: { login: "user3" },
+                  createdAt: "2024-01-15T11:00:00.000Z",
+                },
+              ],
+            },
+          },
+        },
+        user: { login: "trigger-user" },
+      }),
+      rest: jest.fn() as any,
+    };
+
+    const result = await fetchGitHubData({
+      octokits: mockOctokits as any,
+      repository: "test-owner/test-repo",
+      prNumber: "321",
+      isPR: false,
+      triggerUsername: "trigger-user",
+      triggerTime: "2024-01-15T12:00:00Z",
+    });
+
+    // All three comments should be included as they're all before trigger time
+    expect(result.comments.length).toBe(3);
+  });
+});