Add touched/unread inbox issue semantics

server/src/__tests__/issues-user-context.test.ts

@@ -0,0 +1,75 @@
+import { describe, expect, it } from "vitest";
+import { deriveIssueUserContext } from "../services/issues.ts";
+
+function makeIssue(overrides?: Partial<{
+  createdByUserId: string | null;
+  assigneeUserId: string | null;
+  createdAt: Date;
+  updatedAt: Date;
+}>) {
+  return {
+    createdByUserId: null,
+    assigneeUserId: null,
+    createdAt: new Date("2026-03-06T10:00:00.000Z"),
+    updatedAt: new Date("2026-03-06T11:00:00.000Z"),
+    ...overrides,
+  };
+}
+
+describe("deriveIssueUserContext", () => {
+  it("marks issue unread when external comments are newer than my latest comment", () => {
+    const context = deriveIssueUserContext(
+      makeIssue({ createdByUserId: "user-1" }),
+      "user-1",
+      {
+        myLastCommentAt: new Date("2026-03-06T12:00:00.000Z"),
+        lastExternalCommentAt: new Date("2026-03-06T13:00:00.000Z"),
+      },
+    );
+
+    expect(context.myLastTouchAt?.toISOString()).toBe("2026-03-06T12:00:00.000Z");
+    expect(context.lastExternalCommentAt?.toISOString()).toBe("2026-03-06T13:00:00.000Z");
+    expect(context.isUnreadForMe).toBe(true);
+  });
+
+  it("marks issue read when my latest comment is newest", () => {
+    const context = deriveIssueUserContext(
+      makeIssue({ createdByUserId: "user-1" }),
+      "user-1",
+      {
+        myLastCommentAt: new Date("2026-03-06T14:00:00.000Z"),
+        lastExternalCommentAt: new Date("2026-03-06T13:00:00.000Z"),
+      },
+    );
+
+    expect(context.isUnreadForMe).toBe(false);
+  });
+
+  it("uses issue creation time as fallback touch point for creator", () => {
+    const context = deriveIssueUserContext(
+      makeIssue({ createdByUserId: "user-1", createdAt: new Date("2026-03-06T09:00:00.000Z") }),
+      "user-1",
+      {
+        myLastCommentAt: null,
+        lastExternalCommentAt: new Date("2026-03-06T10:00:00.000Z"),
+      },
+    );
+
+    expect(context.myLastTouchAt?.toISOString()).toBe("2026-03-06T09:00:00.000Z");
+    expect(context.isUnreadForMe).toBe(true);
+  });
+
+  it("uses issue updated time as fallback touch point for assignee", () => {
+    const context = deriveIssueUserContext(
+      makeIssue({ assigneeUserId: "user-1", updatedAt: new Date("2026-03-06T15:00:00.000Z") }),
+      "user-1",
+      {
+        myLastCommentAt: null,
+        lastExternalCommentAt: new Date("2026-03-06T14:59:00.000Z"),
+      },
+    );
+
+    expect(context.myLastTouchAt?.toISOString()).toBe("2026-03-06T15:00:00.000Z");
+    expect(context.isUnreadForMe).toBe(false);
+  });
+});