feat(app): cycle agent modes with Shift+Tab

packages/app/src/composer/agent-controls/mode.test.ts

@@ -1,5 +1,14 @@
 import { describe, expect, it } from "vitest";
-import { resolveAgentControlsMode } from "./mode";
+import type { AgentMode } from "@getpaseo/protocol/agent-types";
+import { resolveAgentControlsMode, resolveNextAgentModeId } from "./mode";
+
+const PLAN_MODE = { id: "plan", label: "Plan" } satisfies AgentMode;
+
+const MODES = [
+  PLAN_MODE,
+  { id: "build", label: "Build" },
+  { id: "full-access", label: "Full Access" },
+] satisfies AgentMode[];
 
 describe("resolveAgentControlsMode", () => {
   it("uses ready mode when no controlled agent controls are provided", () => {
@@ -29,3 +38,32 @@ describe("resolveAgentControlsMode", () => {
     ).toBe("draft");
   });
 });
+
+describe("resolveNextAgentModeId", () => {
+  it("cycles from the selected mode to the next mode", () => {
+    expect(resolveNextAgentModeId({ modeOptions: MODES, selectedMode: "build" })).toBe(
+      "full-access",
+    );
+  });
+
+  it("wraps from the last mode to the first mode", () => {
+    expect(resolveNextAgentModeId({ modeOptions: MODES, selectedMode: "full-access" })).toBe(
+      "plan",
+    );
+  });
+
+  it("treats an empty selection as the visible first mode", () => {
+    expect(resolveNextAgentModeId({ modeOptions: MODES, selectedMode: "" })).toBe("build");
+  });
+
+  it("treats a stale selection as the visible first mode", () => {
+    expect(resolveNextAgentModeId({ modeOptions: MODES, selectedMode: "deleted-mode" })).toBe(
+      "build",
+    );
+  });
+
+  it("returns null when there are fewer than two modes", () => {
+    expect(resolveNextAgentModeId({ modeOptions: [], selectedMode: "" })).toBeNull();
+    expect(resolveNextAgentModeId({ modeOptions: [PLAN_MODE], selectedMode: "plan" })).toBeNull();
+  });
+});