Chrome DevTools MCP

/** * @license * Copyright 2025 Google LLC * SPDX-License-Identifier: Apache-2.0 */ import assert from 'node:assert'; import {describe, it} from 'node:test'; import {emulate} from '../../src/tools/emulation.js'; import {withMcpContext} from '../utils.js'; describe('emulation', () => { describe('network', () => { it('emulates offline network conditions', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { networkConditions: 'Offline', }, }, response, context, ); assert.strictEqual(context.getNetworkConditions(), 'Offline'); }); }); it('emulates network throttling when the throttling option is valid', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { networkConditions: 'Slow 3G', }, }, response, context, ); assert.strictEqual(context.getNetworkConditions(), 'Slow 3G'); }); }); it('disables network emulation', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { networkConditions: 'No emulation', }, }, response, context, ); assert.strictEqual(context.getNetworkConditions(), null); }); }); it('does not set throttling when the network throttling is not one of the predefined options', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { networkConditions: 'Slow 11G', }, }, response, context, ); assert.strictEqual(context.getNetworkConditions(), null); }); }); it('report correctly for the currently selected page', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { networkConditions: 'Slow 3G', }, }, response, context, ); assert.strictEqual(context.getNetworkConditions(), 'Slow 3G'); const page = await context.newPage(); context.selectPage(page); assert.strictEqual(context.getNetworkConditions(), null); }); }); }); describe('cpu', () => { it('emulates cpu throttling when the rate is valid (1-20x)', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { cpuThrottlingRate: 4, }, }, response, context, ); assert.strictEqual(context.getCpuThrottlingRate(), 4); }); }); it('disables cpu throttling', async () => { await withMcpContext(async (response, context) => { context.setCpuThrottlingRate(4); // Set it to something first. await emulate.handler( { params: { cpuThrottlingRate: 1, }, }, response, context, ); assert.strictEqual(context.getCpuThrottlingRate(), 1); }); }); it('report correctly for the currently selected page', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { cpuThrottlingRate: 4, }, }, response, context, ); assert.strictEqual(context.getCpuThrottlingRate(), 4); const page = await context.newPage(); context.selectPage(page); assert.strictEqual(context.getCpuThrottlingRate(), 1); }); }); }); describe('geolocation', () => { it('emulates geolocation with latitude and longitude', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { geolocation: { latitude: 48.137154, longitude: 11.576124, }, }, }, response, context, ); const geolocation = context.getGeolocation(); assert.strictEqual(geolocation?.latitude, 48.137154); assert.strictEqual(geolocation?.longitude, 11.576124); }); }); it('clears geolocation override when geolocation is set to null', async () => { await withMcpContext(async (response, context) => { // First set a geolocation await emulate.handler( { params: { geolocation: { latitude: 48.137154, longitude: 11.576124, }, }, }, response, context, ); assert.notStrictEqual(context.getGeolocation(), null); // Then clear it by setting geolocation to null await emulate.handler( { params: { geolocation: null, }, }, response, context, ); assert.strictEqual(context.getGeolocation(), null); }); }); it('reports correctly for the currently selected page', async () => { await withMcpContext(async (response, context) => { await emulate.handler( { params: { geolocation: { latitude: 48.137154, longitude: 11.576124, }, }, }, response, context, ); const geolocation = context.getGeolocation(); assert.strictEqual(geolocation?.latitude, 48.137154); assert.strictEqual(geolocation?.longitude, 11.576124); const page = await context.newPage(); context.selectPage(page); assert.strictEqual(context.getGeolocation(), null); }); }); }); });