core+app: reviewer chat — ask the agent about the review, adopt drafted comments

app/src-tauri/src/commands/mod.rs

@@ -3,6 +3,7 @@
 //! Commands parse params, call core, and map results through
 //! [`CommandError`](crate::error::CommandError). All logic lives in core.
 
+pub mod chat;
 pub mod shell;
 
 use std::collections::HashSet;

app/src-tauri/src/lib.rs

@@ -319,6 +319,8 @@ pub fn run() {
             Ok(())
         })
         .invoke_handler(tauri::generate_handler![
+            commands::chat::send_chat_message,
+            commands::chat::cancel_chat_turn,
             commands::list_reviews,
             commands::get_frontier,
             commands::get_review,
@@ -792,6 +794,9 @@ fn clear_head_anchored_annotations(review: &mut Review) {
     review.review_findings.clear();
     review.distilled_intent = None;
     review.distilled_headline = None;
+    // The chat thread answers questions about the previous head; stale answers
+    // are worse than no answers (cockpit-docs/REVIEWER_CHAT.md).
+    review.chat.clear();
 }
 
 /// Extract the PR number from a PR URL or reference string.
@@ -1426,6 +1431,7 @@ mod tests {
             distilled_intent: None,
             distilled_headline: None,
             recap_sha: None,
+            chat: Vec::new(),
         }
     }
 
@@ -1525,6 +1531,14 @@ mod tests {
         }];
         review.distilled_intent = Some("intent".into());
         review.recap_sha = Some("headsha9".into());
+        review.chat = vec![cockpit_core::model::ChatMessage {
+            id: cockpit_core::model::ChatMessageId::new("cm-1"),
+            role: cockpit_core::model::ChatRole::User,
+            text: "q".into(),
+            drafts: Vec::new(),
+            error: false,
+            created_at_epoch_ms: 1,
+        }];
 
         clear_head_anchored_annotations(&mut review);
 
@@ -1536,6 +1550,7 @@ mod tests {
             review.distilled_intent.is_none(),
             "intent cleared on refresh"
         );
+        assert!(review.chat.is_empty(), "chat cleared on refresh");
         assert_eq!(
             review.recap_sha.as_deref(),
             Some("headsha9"),

app/src-tauri/src/state.rs

@@ -51,6 +51,14 @@ pub struct AppState {
     /// is only ever held for trivial map lookups/inserts — never across an
     /// `.await`.
     pub lsp_bridges: Mutex<HashMap<LspLanguage, LspBridge>>,
+
+    /// In-flight reviewer-chat turns, PR ref → agent pid.
+    ///
+    /// Enforces one turn per PR and gives `cancel_chat_turn` its kill target.
+    /// Chat turns are transient (never attached to `Review::agent`), so this
+    /// registry is their only handle. The `std::sync::Mutex` is held only for
+    /// trivial map operations — never across an `.await`.
+    pub chat_turns: Mutex<HashMap<String, u32>>,
 }
 
 impl AppState {
@@ -67,6 +75,7 @@ impl AppState {
             completion_tx,
             permission_broker,
             lsp_bridges: Mutex::new(HashMap::new()),
+            chat_turns: Mutex::new(HashMap::new()),
         }
     }
 }

app/src/App.tsx

@@ -97,6 +97,20 @@ interface AgentEventEnvelope {
   readonly event: AgentStreamEvent;
 }
 
+/** Payload of the reviewer-chat `"chat-stream"` event (hand-typed, no ts-rs). */
+interface ChatStreamPayload {
+  readonly pr: string;
+  readonly message_id: string;
+  readonly delta: string;
+}
+
+/** Payload of the reviewer-chat `"chat-complete"` event (hand-typed, no ts-rs). */
+interface ChatCompletePayload {
+  readonly pr: string;
+  readonly message_id: string;
+  readonly ok: boolean;
+}
+
 type ReviewTab = "my-prs" | "review-requests" | "all";
 
 const SIDEBAR_COLLAPSED_KEY = "cockpit-sidebar-collapsed";
@@ -603,7 +617,30 @@ function App() {
       },
     );
 
+    // Reviewer chat: stream deltas into the in-flight bubble; on completion
+    // settle the turn (the persisted agent message lands via review refresh).
+    const unlistenChatStream = listen<ChatStreamPayload>(
+      "chat-stream",
+      (event) => {
+        useAppStore
+          .getState()
+          .applyChatDelta(event.payload.pr, event.payload.delta);
+      },
+    );
+    const unlistenChatComplete = listen<ChatCompletePayload>(
+      "chat-complete",
+      (event) => {
+        void useAppStore.getState().completeChatTurn(event.payload.pr);
+      },
+    );
+
     return () => {
+      void unlistenChatStream.then((f) => {
+        f();
+      });
+      void unlistenChatComplete.then((f) => {
+        f();
+      });
       void unlisten.then((f) => {
         f();
       });

app/src/bindings/ChatMessage.ts

@@ -0,0 +1,37 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { ChatMessageId } from "./ChatMessageId";
+import type { ChatRole } from "./ChatRole";
+import type { DraftComment } from "./DraftComment";
+
+/**
+ * One message in a review's chat thread with the reviewer agent.
+ *
+ * The thread is head-anchored context like findings and the distilled
+ * intent: it is cleared when the head moves, since answers about superseded
+ * code go stale.
+ */
+export type ChatMessage = { 
+/**
+ * Locally-unique message id.
+ */
+id: ChatMessageId, 
+/**
+ * Who authored the message.
+ */
+role: ChatRole, 
+/**
+ * The message text (markdown; draft blocks already stripped).
+ */
+text: string, 
+/**
+ * Draft comments proposed by the agent in this turn (usually empty).
+ */
+drafts: Array<DraftComment>, 
+/**
+ * Whether this agent message reports a failed turn (spawn/timeout/parse).
+ */
+error: boolean, 
+/**
+ * Wall-clock creation time in epoch milliseconds.
+ */
+created_at_epoch_ms: number, };

app/src/bindings/ChatMessageId.ts

@@ -0,0 +1,6 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+/**
+ * Locally-unique identifier for a [`ChatMessage`] in a review's thread.
+ */
+export type ChatMessageId = string;

app/src/bindings/ChatRole.ts

@@ -0,0 +1,6 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+
+/**
+ * Who authored a [`ChatMessage`] in a review's chat thread.
+ */
+export type ChatRole = "User" | "Agent";

app/src/bindings/DraftComment.ts

@@ -0,0 +1,27 @@
+// This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
+import type { DiffSide } from "./DiffSide";
+
+/**
+ * A review comment the chat agent proposes, for the reviewer to adopt.
+ *
+ * A draft is a *proposal only*: it becomes a real [`Comment`] exclusively
+ * through the reviewer's explicit adopt action, and reaches GitHub only via
+ * the guarded mirror / submit-review flows (Invariant §9).
+ */
+export type DraftComment = { 
+/**
+ * Path relative to the repo root.
+ */
+path: string, 
+/**
+ * Inclusive start and end line in the current head.
+ */
+range: [number, number], 
+/**
+ * Which side of the diff the range refers to.
+ */
+side: DiffSide, 
+/**
+ * The proposed comment body (markdown).
+ */
+body: string, };

app/src/bindings/Review.ts

@@ -1,5 +1,6 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 import type { AgentRun } from "./AgentRun";
+import type { ChatMessage } from "./ChatMessage";
 import type { CiSummary } from "./CiSummary";
 import type { Comment } from "./Comment";
 import type { ConversationItem } from "./ConversationItem";
@@ -165,4 +166,12 @@ distilled_headline: string | null,
  * tab can nudge a regenerate. Deliberately NOT cleared when the head moves
  * (unlike `review_findings` / `distilled_intent`) so staleness is derivable.
  */
-recap_sha: string | null, };
+recap_sha: string | null, 
+/**
+ * The chat thread between the reviewer and the read-only reviewer agent.
+ *
+ * Head-anchored like `review_findings` / `distilled_intent`: cleared when
+ * the head moves. `#[serde(default)]` keeps legacy persisted reviews
+ * loading with an empty thread.
+ */
+chat: Array<ChatMessage>, };

app/src/components/ChatPanel.test.tsx

@@ -0,0 +1,125 @@
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { makeReview } from "../test/fixtures";
+import { mockInvoke, callsFor } from "../test/tauri-mock";
+import type { ChatMessage } from "../bindings/ChatMessage";
+
+vi.mock("@tauri-apps/api/core", async () => {
+  const mock = await import("../test/tauri-mock");
+  return { invoke: mock.invoke };
+});
+vi.mock("@tauri-apps/api/event", async () => {
+  const mock = await import("../test/tauri-mock");
+  return { listen: mock.listen };
+});
+vi.mock("@tauri-apps/plugin-opener", () => ({
+  openUrl: vi.fn(() => Promise.resolve()),
+}));
+
+const { useAppStore } = await import("../store");
+const { ChatPanel } = await import("./ChatPanel");
+
+const agentMessage: ChatMessage = {
+  id: "cm-a1",
+  role: "Agent",
+  text: "The flag gates every entry point.",
+  drafts: [
+    {
+      path: "src/a.py",
+      range: [57, 57],
+      side: "New",
+      body: "Use the no-retry policy.",
+    },
+  ],
+  error: false,
+  created_at_epoch_ms: 2,
+};
+
+const userMessage: ChatMessage = {
+  id: "cm-u1",
+  role: "User",
+  text: "What does the flag gate?",
+  drafts: [],
+  error: false,
+  created_at_epoch_ms: 1,
+};
+
+describe("ChatPanel", () => {
+  it("renders the thread and adopts a draft via add_comment", () => {
+    const review = {
+      ...makeReview({ gate_state: "InReview" }),
+      chat: [userMessage, agentMessage],
+    };
+    useAppStore.setState({
+      activeReview: review,
+      view: { kind: "diff", pr: review.pr },
+    });
+    mockInvoke("add_comment", () => review);
+
+    render(<ChatPanel review={review} onClose={() => undefined} />);
+
+    expect(screen.getByText("What does the flag gate?")).toBeDefined();
+    expect(
+      screen.getByText("The flag gates every entry point."),
+    ).toBeDefined();
+
+    fireEvent.click(screen.getByRole("button", { name: "Add to review" }));
+    const calls = callsFor("add_comment");
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.args).toMatchObject({
+      file: "src/a.py",
+      lineStart: 57,
+      lineEnd: 57,
+      body: "Use the no-retry policy.",
+      side: "New",
+    });
+  });
+
+  it("shows the adopted state instead of the button once a comment matches", () => {
+    const base = makeReview({ gate_state: "InReview" });
+    const review = {
+      ...base,
+      chat: [agentMessage],
+      comments: [
+        {
+          id: "c-1",
+          anchor: {
+            DiffLine: {
+              path: "src/a.py",
+              range: [57, 57] as [number, number],
+              side: "New" as const,
+            },
+          },
+          body: "Use the no-retry policy.",
+          origin: "Local" as const,
+        },
+      ],
+    };
+    render(<ChatPanel review={review} onClose={() => undefined} />);
+    expect(screen.queryByRole("button", { name: "Add to review" })).toBeNull();
+    expect(screen.getByText("Added ✓")).toBeDefined();
+  });
+
+  it("disables send on empty input and marks error turns", () => {
+    const review = {
+      ...makeReview({ gate_state: "InReview" }),
+      chat: [
+        {
+          ...agentMessage,
+          id: "cm-err",
+          drafts: [],
+          error: true,
+          text: "The reviewer agent timed out after 5 minutes and was stopped.",
+        },
+      ],
+    };
+    render(<ChatPanel review={review} onClose={() => undefined} />);
+    const send = screen.getByRole("button", { name: "Send message" });
+    expect((send as HTMLButtonElement).disabled).toBe(true);
+    expect(
+      screen.getByText(
+        "The reviewer agent timed out after 5 minutes and was stopped.",
+      ),
+    ).toBeDefined();
+  });
+});