test: add unit tests for isCompactedEvent and createCompactedEvent

core/test/events/compacted_event_test.ts

@@ -0,0 +1,99 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {createEvent} from '@google/adk';
+import {describe, expect, it} from 'vitest';
+import {
+  createCompactedEvent,
+  isCompactedEvent,
+} from '../../src/events/compacted_event.js';
+
+describe('isCompactedEvent', () => {
+  it('returns true for a valid CompactedEvent', () => {
+    const event = createCompactedEvent({
+      author: 'system',
+      startTime: 1000,
+      endTime: 2000,
+      compactedContent: 'summary',
+    });
+    expect(isCompactedEvent(event)).toBe(true);
+  });
+
+  it('returns false for a plain Event', () => {
+    const event = createEvent({author: 'user'});
+    expect(isCompactedEvent(event)).toBe(false);
+  });
+
+  it('returns false when isCompacted field is missing', () => {
+    const event = createEvent({author: 'agent'}) as object;
+    expect(isCompactedEvent(event as ReturnType<typeof createEvent>)).toBe(
+      false,
+    );
+  });
+
+  it('returns false when isCompacted is false', () => {
+    const event = {
+      ...createEvent({author: 'agent'}),
+      isCompacted: false,
+    } as ReturnType<typeof createEvent>;
+    expect(isCompactedEvent(event)).toBe(false);
+  });
+});
+
+describe('createCompactedEvent', () => {
+  it('creates a CompactedEvent with isCompacted set to true', () => {
+    const event = createCompactedEvent({
+      startTime: 100,
+      endTime: 200,
+      compactedContent: 'summary text',
+    });
+    expect(event.isCompacted).toBe(true);
+  });
+
+  it('carries startTime, endTime, and compactedContent', () => {
+    const event = createCompactedEvent({
+      startTime: 500,
+      endTime: 1500,
+      compactedContent: 'key decisions were made',
+    });
+    expect(event.startTime).toBe(500);
+    expect(event.endTime).toBe(1500);
+    expect(event.compactedContent).toBe('key decisions were made');
+  });
+
+  it('merges base event defaults (id, invocationId, actions)', () => {
+    const event = createCompactedEvent({
+      startTime: 0,
+      endTime: 0,
+      compactedContent: '',
+    });
+    expect(event.id).toBeDefined();
+    expect(event.id.length).toBeGreaterThan(0);
+    expect(event.invocationId).toBe('');
+    expect(event.actions).toBeDefined();
+  });
+
+  it('accepts author and content from params', () => {
+    const event = createCompactedEvent({
+      author: 'system',
+      content: {role: 'model', parts: [{text: 'summary'}]},
+      startTime: 0,
+      endTime: 10,
+      compactedContent: 'summary',
+    });
+    expect(event.author).toBe('system');
+    expect(event.content?.parts?.[0]?.text).toBe('summary');
+  });
+
+  it('satisfies the isCompactedEvent type guard after creation', () => {
+    const event = createCompactedEvent({
+      startTime: 0,
+      endTime: 0,
+      compactedContent: '',
+    });
+    expect(isCompactedEvent(event)).toBe(true);
+  });
+});