feat: CoeditingRegistry opt-in gate (INV-10, spec §6.4) — enter/stop commands + context keys

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/coeditingRegistry.test.ts

@@ -0,0 +1,63 @@
+import { describe, expect, it, vi } from "vitest";
+
+// The pure set logic lives in a vscode-free helper the class wraps, so unit-test the class
+// with a Memento stub (vitest runs vscode-free; the module imports vscode only for types +
+// EventEmitter — mock it).
+vi.mock("vscode", () => ({
+  EventEmitter: class {
+    private handlers: Array<(e: unknown) => void> = [];
+    event = (h: (e: unknown) => void) => { this.handlers.push(h); return { dispose() {} }; };
+    fire(e: unknown) { for (const h of this.handlers) h(e); }
+    dispose() {}
+  },
+  Uri: { parse: (s: string) => ({ toString: () => s }) },
+  commands: { executeCommand: vi.fn() },
+  window: { activeTextEditor: undefined },
+}));
+import { CoeditingRegistry } from "../src/coeditingRegistry";
+
+function memento(): { store: Map<string, unknown> } & { get: any; update: any } {
+  const store = new Map<string, unknown>();
+  return {
+    store,
+    get: (k: string, dflt?: unknown) => (store.has(k) ? store.get(k) : dflt),
+    update: (k: string, v: unknown) => { store.set(k, v); return Promise.resolve(); },
+  } as any;
+}
+
+describe("CoeditingRegistry", () => {
+  it("enter/exit flips membership and fires onDidChange", () => {
+    const reg = new CoeditingRegistry(memento() as any);
+    const events: Array<{ uri: string; coediting: boolean }> = [];
+    reg.onDidChange((e) => events.push(e as any));
+    const uri = { toString: () => "file:///a.md" } as any;
+    expect(reg.isCoediting(uri)).toBe(false);
+    reg.enter(uri);
+    expect(reg.isCoediting(uri)).toBe(true);
+    reg.exit(uri);
+    expect(reg.isCoediting(uri)).toBe(false);
+    expect(events).toEqual([
+      { uri: "file:///a.md", coediting: true },
+      { uri: "file:///a.md", coediting: false },
+    ]);
+  });
+
+  it("persists the set across construction (reload survival)", () => {
+    const m = memento();
+    const reg1 = new CoeditingRegistry(m as any);
+    reg1.enter({ toString: () => "file:///a.md" } as any);
+    const reg2 = new CoeditingRegistry(m as any);
+    expect(reg2.isCoediting({ toString: () => "file:///a.md" } as any)).toBe(true);
+    expect(reg2.list()).toEqual(["file:///a.md"]);
+  });
+
+  it("enter is idempotent (no duplicate events)", () => {
+    const reg = new CoeditingRegistry(memento() as any);
+    const events: unknown[] = [];
+    reg.onDidChange((e) => events.push(e));
+    const uri = { toString: () => "file:///a.md" } as any;
+    reg.enter(uri);
+    reg.enter(uri);
+    expect(events).toHaveLength(1);
+  });
+});

test/e2e/suite/coediting.test.ts

@@ -0,0 +1,20 @@
+import * as assert from "node:assert";
+import * as vscode from "vscode";
+
+async function api() {
+  const ext = vscode.extensions.getExtension("benstull.vscode-cowriting-plugin")!;
+  return (await ext.activate()) as import("../../../src/extension").CowritingApi;
+}
+
+suite("coediting registry (PUC-7)", () => {
+  test("enter → isCoediting true; exit → false; persists in list()", async () => {
+    const { coeditingRegistry } = await api();
+    const doc = await vscode.workspace.openTextDocument({ language: "markdown", content: "# t\n\nbody\n" });
+    await vscode.window.showTextDocument(doc);
+    await vscode.commands.executeCommand("cowriting.coeditDocument");
+    assert.strictEqual(coeditingRegistry.isCoediting(doc.uri), true);
+    assert.ok(coeditingRegistry.list().includes(doc.uri.toString()));
+    await vscode.commands.executeCommand("cowriting.stopCoediting");
+    assert.strictEqual(coeditingRegistry.isCoediting(doc.uri), false);
+  });
+});