fusion/packages/engine/src/pr-comment-handler.test.ts

import { describe, it, expect, vi, beforeEach } from "vitest";
import { PrCommentHandler } from "./pr-comment-handler.js";
import type { TaskStore, Task } from "@fusion/core";

const mockStore = {
  addTaskComment: vi.fn<(id: string, text: string, author?: string) => Promise<Task>>(),
  createTask: vi.fn<(input: Parameters<TaskStore["createTask"]>[0]) => Promise<Task>>().mockResolvedValue({ id: "FN-123" } as Task),
} as unknown as TaskStore;

describe("PrCommentHandler", () => {
  let handler: PrCommentHandler;

  beforeEach(() => {
    vi.clearAllMocks();
    handler = new PrCommentHandler(mockStore);
  });

  const mockPrInfo = {
    url: "https://github.com/owner/repo/pull/42",
    number: 42,
    status: "open" as const,
    title: "Test PR",
    headBranch: "fusion/fn-001",
    baseBranch: "main",
    commentCount: 0,
  };

  describe("isNonActionable", () => {
    it.each([
      "LGTM",
      "lgtm",
      "Looks good",
      "Looks good to me",
      "Thanks",
      "Thank you",
      "Nice",
      "Great work",
      "👍",
      "✅",
    ])("filters out non-actionable comment: %s", async (body) => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body,
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.addTaskComment).not.toHaveBeenCalled();
    });
  });

  describe("isActionable", () => {
    it.each([
      { body: "Please fix the indentation", keyword: "fix" },
      { body: "Should change the variable name", keyword: "change" },
      { body: "Update the documentation", keyword: "update" },
      { body: "Remove the unused import", keyword: "remove" },
      { body: "Add error handling", keyword: "add" },
      { body: "You should refactor this", keyword: "should" },
      { body: "Needs to handle edge cases", keyword: "needs to" },
      { body: "Consider using a different approach", keyword: "consider" },
      { body: "I suggest renaming this", keyword: "suggest" },
      { body: "Recommend adding tests", keyword: "recommend" },
    ])("creates comment for actionable feedback containing '$keyword': $body", async ({ body }) => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body,
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.addTaskComment).toHaveBeenCalled();
    });
  });

  describe("code suggestions", () => {
    it("creates comment for comments with code blocks", async () => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "```typescript\nconst x = 1;\n```",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.addTaskComment).toHaveBeenCalled();
    });

    it("creates comment for inline code suggestions", async () => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "Use `const` instead of `let`",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.addTaskComment).toHaveBeenCalled();
    });
  });

  describe("comment content", () => {
    it("includes PR info and comment details", async () => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "Please fix the bug",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      const call = (mockStore.addTaskComment as ReturnType<typeof vi.fn>).mock.calls[0];
      const text = call[1] as string;

      expect(text).toContain("PR Review Feedback");
      expect(text).toContain("@reviewer");
      expect(text).toContain("#42");
      expect(text).toContain("open");
      expect(text).toContain("Please fix the bug");
      expect(text).toContain("View on GitHub");
    });

    it("truncates long comments", async () => {
      const longBody = "Please fix this issue: " + "a".repeat(1000);

      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body: longBody,
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      const call = (mockStore.addTaskComment as ReturnType<typeof vi.fn>).mock.calls[0];
      const text = call[1] as string;

      expect(text.length).toBeLessThan(longBody.length);
      expect(text).toContain("...");
    });

    it("marks as agent-authored", async () => {
      await handler.handleNewComments("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "Please fix this",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.addTaskComment).toHaveBeenCalledWith(
        "FN-001",
        expect.any(String),
        "agent"
      );
    });

    it("calls out follow-up context when feedback arrives after PR is merged", async () => {
      await handler.handleNewComments("FN-001", { ...mockPrInfo, status: "merged" }, [
        {
          id: 1,
          body: "Please add one more regression test",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      const text = (mockStore.addTaskComment as ReturnType<typeof vi.fn>).mock.calls[0][1] as string;
      expect(text).toContain("This PR is already merged");
      expect(text).toContain("follow-up work");
    });
  });

  describe("createFollowUpTask", () => {
    it("creates follow-up task for unaddressed feedback", async () => {
      await handler.createFollowUpTask("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "This needs fixing",
          user: { login: "reviewer" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
      ]);

      expect(mockStore.createTask).toHaveBeenCalledWith({
        title: "Follow-up: Address PR #42 feedback",
        description: expect.stringContaining("FN-001"),
        column: "triage",
        dependencies: ["FN-001"],
      });
    });

    it("does nothing when no unaddressed comments", async () => {
      await handler.createFollowUpTask("FN-001", mockPrInfo, []);

      expect(mockStore.createTask).not.toHaveBeenCalled();
    });

    it("summarizes multiple comments", async () => {
      await handler.createFollowUpTask("FN-001", mockPrInfo, [
        {
          id: 1,
          body: "First issue to fix",
          user: { login: "reviewer1" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-1",
        },
        {
          id: 2,
          body: "Second issue",
          user: { login: "reviewer2" },
          created_at: new Date().toISOString(),
          updated_at: new Date().toISOString(),
          html_url: "https://github.com/owner/repo/pull/42#issuecomment-2",
        },
      ]);

      const call = (mockStore.createTask as ReturnType<typeof vi.fn>).mock.calls[0];
      const description = call[0].description as string;

      expect(description).toContain("@reviewer1");
      expect(description).toContain("@reviewer2");
      expect(description).toContain("First issue");
      expect(description).toContain("Second issue");
    });
  });
});