feat: include PR conversation comments for review_comments subscribers (#96)

* feat: include PR conversation comments for review_comments subscribers

When user subscribes to review_comments, PR conversation comments
(from the Conversation tab) are now also delivered. This matches
user expectation that review_comments covers all PR comments.

- Issue comments still only match "comments" subscribers
- Inline code review comments still only match "review_comments"
- PR conversation comments now match both

* test: add PR comment routing tests and document behavior

Add unit tests verifying:
- comments subscribers receive PR conversation comments
- review_comments subscribers receive PR conversation comments
- review_comments subscribers do NOT receive issue comments

Update README to document comment routing behavior.

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: shuhuiluo

README.md

@@ -68,6 +68,8 @@ First-time subscriptions open an OAuth window; after authorization the callback
 
 **Event types:** `pr`, `issues`, `commits`, `releases`, `ci`, `comments`, `reviews`, `branches`, `review_comments`, `forks`, `stars`, `all`
 
+> **Comment routing:** `comments` includes both issue comments and PR conversation comments. `review_comments` covers inline code review comments AND also receives PR conversation comments (useful for PR-focused subscriptions without issue noise).
+
 **Branch filter:** `--branches main,develop` or `--branches release/*` or `--branches all` (default: default branch only)
 
 > Branch filtering applies to: `pr`, `commits`, `ci`, `reviews`, `review_comments`, `branches`. Other events (`issues`, `releases`, `comments`, `forks`, `stars`) are not branch-specific.
@@ -109,9 +111,9 @@ First-time subscriptions open an OAuth window; after authorization the callback
 - `push` - Commits to branches
 - `release` - Published
 - `workflow_run` - CI/CD status
-- `issue_comment` - New comments (threaded to PR/issue)
+- `issue_comment` - Comments on issues and PR conversations (threaded; routes to `comments`, also `review_comments` for PRs)
 - `pull_request_review` - PR reviews (threaded to PR)
-- `pull_request_review_comment` - Review comments (threaded to PR)
+- `pull_request_review_comment` - Inline code review comments (threaded to PR; routes to `review_comments`)
 - `create` / `delete` - Branch/tag creation and deletion
 - `fork` - Repository forks
 - `watch` - Repository stars

src/github-app/event-processor.ts

@@ -101,9 +101,18 @@ export class EventProcessor {
     );
 
     // Filter by event preferences
-    let interestedChannels = channels.filter(ch =>
-      ch.eventTypes.includes(eventType)
-    );
+    let interestedChannels = channels.filter(ch => {
+      if (ch.eventTypes.includes(eventType)) return true;
+      // PR conversation comments also notify review_comments subscribers
+      if (
+        eventType === "comments" &&
+        entityContext?.parentType === "pr" &&
+        ch.eventTypes.includes("review_comments")
+      ) {
+        return true;
+      }
+      return false;
+    });
 
     // Apply branch filtering for branch-specific events
     if (branch) {

tests/unit/github-app/event-processor.test.ts

@@ -1,6 +1,14 @@
-import { describe, expect, test } from "bun:test";
-
-import { matchesBranchFilter } from "../../../src/github-app/event-processor";
+import { describe, expect, mock, test } from "bun:test";
+
+import type { EventType } from "../../../src/constants";
+import type { GitHubApp } from "../../../src/github-app/app";
+import {
+  EventProcessor,
+  matchesBranchFilter,
+} from "../../../src/github-app/event-processor";
+import type { MessageDeliveryService } from "../../../src/services/message-delivery-service";
+import type { SubscriptionService } from "../../../src/services/subscription-service";
+import type { IssueCommentPayload } from "../../../src/types/webhooks";
 
 describe("matchesBranchFilter", () => {
   const defaultBranch = "main";
@@ -133,3 +141,114 @@ describe("matchesBranchFilter", () => {
     });
   });
 });
+
+describe("PR comment routing", () => {
+  // Helper to create minimal IssueCommentPayload for testing
+  const createIssueCommentPayload = (
+    isPrComment: boolean
+  ): IssueCommentPayload =>
+    ({
+      action: "created",
+      repository: {
+        full_name: "owner/repo",
+        default_branch: "main",
+      },
+      issue: {
+        number: 123,
+        // GitHub includes pull_request field only for PR comments
+        ...(isPrComment ? { pull_request: { url: "https://..." } } : {}),
+      },
+      comment: {
+        id: 456,
+        updated_at: new Date().toISOString(),
+      },
+    }) as unknown as IssueCommentPayload;
+
+  // Helper to create mock services
+  const createMocks = (channels: Array<{ eventTypes: EventType[] }>) => {
+    const deliveredChannels: string[] = [];
+
+    const mockSubscriptionService = {
+      getRepoSubscribers: mock(() =>
+        Promise.resolve(
+          channels.map((ch, i) => ({
+            channelId: `channel-${i}`,
+            spaceId: `space-${i}`,
+            eventTypes: ch.eventTypes,
+            branchFilter: "all" as const,
+          }))
+        )
+      ),
+    } as unknown as SubscriptionService;
+
+    const mockMessageDeliveryService = {
+      deliver: mock(({ channelId }: { channelId: string }) => {
+        deliveredChannels.push(channelId);
+        return Promise.resolve();
+      }),
+    } as unknown as MessageDeliveryService;
+
+    const mockGitHubApp = {} as GitHubApp;
+
+    const processor = new EventProcessor(
+      mockGitHubApp,
+      mockSubscriptionService,
+      mockMessageDeliveryService
+    );
+
+    return { processor, deliveredChannels };
+  };
+
+  test("channel subscribed to 'comments' receives PR conversation comment", async () => {
+    const { processor, deliveredChannels } = createMocks([
+      { eventTypes: ["comments"] },
+    ]);
+
+    await processor.onIssueComment(createIssueCommentPayload(true));
+
+    expect(deliveredChannels).toContain("channel-0");
+  });
+
+  test("channel subscribed to 'review_comments' receives PR conversation comment", async () => {
+    const { processor, deliveredChannels } = createMocks([
+      { eventTypes: ["review_comments"] },
+    ]);
+
+    await processor.onIssueComment(createIssueCommentPayload(true));
+
+    expect(deliveredChannels).toContain("channel-0");
+  });
+
+  test("channel subscribed to 'review_comments' does NOT receive issue comment", async () => {
+    const { processor, deliveredChannels } = createMocks([
+      { eventTypes: ["review_comments"] },
+    ]);
+
+    await processor.onIssueComment(createIssueCommentPayload(false));
+
+    expect(deliveredChannels).not.toContain("channel-0");
+  });
+
+  test("both subscribers receive PR conversation comment", async () => {
+    const { processor, deliveredChannels } = createMocks([
+      { eventTypes: ["comments"] },
+      { eventTypes: ["review_comments"] },
+    ]);
+
+    await processor.onIssueComment(createIssueCommentPayload(true));
+
+    expect(deliveredChannels).toContain("channel-0");
+    expect(deliveredChannels).toContain("channel-1");
+    expect(deliveredChannels.length).toBe(2);
+  });
+
+  test("channel without comment subscriptions does not receive comment", async () => {
+    const { processor, deliveredChannels } = createMocks([
+      { eventTypes: ["pr", "issues"] },
+    ]);
+
+    await processor.onIssueComment(createIssueCommentPayload(true));
+
+    expect(deliveredChannels.length).toBe(0);
+  });
+});