feat(agent): add frontend action bridge

tests/frontendAction/callIdPlugin.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "bun:test";
+
+import { frontendActionCallIdPlugin } from "../../.opencode/plugins/frontend-action-call-id.js";
+
+describe("frontend action call ID plugin", () => {
+  it("overwrites forged IDs only for allowlisted tools", async () => {
+    const hooks = await frontendActionCallIdPlugin({} as never);
+    const before = hooks["tool.execute.before"];
+    if (!before) throw new Error("hook missing");
+    const actionOutput = { args: { x: 1, __frontend_action_call_id: "forged" } };
+    await before({ tool: "zoom_to_map", sessionID: "session", callID: "real" }, actionOutput);
+    expect(actionOutput.args.__frontend_action_call_id).toBe("real");
+
+    const ordinaryOutput = { args: { query: "water" } };
+    await before({ tool: "web_search", sessionID: "session", callID: "ignored" }, ordinaryOutput);
+    expect(ordinaryOutput.args).toEqual({ query: "water" });
+  });
+});

tests/frontendAction/coordinator.test.ts

@@ -0,0 +1,47 @@
+import { describe, expect, it } from "bun:test";
+
+import { FrontendActionCoordinator, FrontendActionError } from "../../src/frontendAction/coordinator.js";
+import type { FrontendActionRequest } from "../../src/frontendAction/types.js";
+
+const start = (coordinator: FrontendActionCoordinator, sessionId = "session-1") => {
+  let emitted: FrontendActionRequest | undefined;
+  coordinator.registerSink(sessionId, (request) => { emitted = request; });
+  const pending = coordinator.request({ sessionId, toolCallId: "call-1", name: "zoom_to_map", params: { x: 117.2, y: 39.1 } });
+  if (!emitted) throw new Error("request was not emitted");
+  return { emitted, pending };
+};
+
+describe("FrontendActionCoordinator", () => {
+  it("emits once and resolves with a validated browser result", async () => {
+    const coordinator = new FrontendActionCoordinator();
+    const { emitted, pending } = start(coordinator);
+    const result = { version: "frontend-action-result@1" as const, actionId: emitted.actionId, status: "succeeded" as const, output: { zoom: 14 }, completedAt: Date.now() };
+    expect(coordinator.submitResult("session-1", result).duplicate).toBe(false);
+    expect((await pending).output).toEqual({ zoom: 14 });
+    expect(coordinator.submitResult("session-1", result).duplicate).toBe(true);
+  });
+
+  it("rejects conflicting terminal results and cross-session submissions", async () => {
+    const coordinator = new FrontendActionCoordinator();
+    const { emitted, pending } = start(coordinator);
+    const result = { version: "frontend-action-result@1" as const, actionId: emitted.actionId, status: "succeeded" as const, output: {}, completedAt: Date.now() };
+    expect(() => coordinator.submitResult("other", result)).toThrow("session mismatch");
+    coordinator.submitResult("session-1", result);
+    await pending;
+    expect(() => coordinator.submitResult("session-1", { ...result, completedAt: result.completedAt + 1 })).toThrow("conflicts");
+  });
+
+  it("cancels all pending actions for a session", async () => {
+    const coordinator = new FrontendActionCoordinator();
+    const { pending } = start(coordinator);
+    coordinator.cancelSession("session-1");
+    expect((await pending).status).toBe("cancelled");
+  });
+
+  it("validates params and requires an active browser sink", () => {
+    const coordinator = new FrontendActionCoordinator();
+    expect(() => coordinator.request({ sessionId: "s", toolCallId: "c", name: "zoom_to_map", params: { x: "bad", y: 1 } })).toThrow(FrontendActionError);
+    coordinator.registerSink("s", () => undefined);
+    expect(() => coordinator.request({ sessionId: "s", toolCallId: "c", name: "unknown", params: {} })).toThrow("unknown frontend action");
+  });
+});