/**
* @ license
* Copyright 2017 Google Inc .
* SPDX - License - Identifier : Apache - 2 . 0
*/
import fs from 'node:fs' ;
import path from 'node:path' ;
import expect from 'expect' ;
import {launch} from './mocha-utils.js' ;
describe('Tracing' , function () {
let outputFile!: string;
let testState: Awaited<ReturnType<typeof launch>>;
/* we manually manage the browser here as we want a new browser for each
* individual test , which isn ' t the default behaviour of getTestState ( )
*/
beforeEach(async () => {
testState = await launch({}, {createContext: true });
outputFile = path.join(import .meta.dirname, 'trace.json' );
});
afterEach(async () => {
await testState.close();
if (fs.existsSync(outputFile)) {
fs.unlinkSync(outputFile);
}
});
it('should output a trace' , async () => {
const {server, page} = testState;
await page.tracing.start({screenshots: true , path: outputFile});
await page.goto (server.PREFIX + '/grid.html' );
await page.tracing.stop();
expect(fs.existsSync(outputFile)).toBe(true );
});
it('should run with custom categories if provided' , async () => {
const {page} = testState;
await page.tracing.start({
path: outputFile,
categories: ['-*' , 'disabled-by-default-devtools.timeline.frame' ],
});
await page.tracing.stop();
const traceJson = JSON.parse(
fs.readFileSync(outputFile, {encoding: 'utf8' }),
);
expect(traceJson.traceEvents).not.toContainEqual(
expect.objectContaining({
cat: 'toplevel' ,
}),
);
});
it('should run with default categories' , async () => {
const {page} = testState;
await page.tracing.start({
path: outputFile,
});
await page.tracing.stop();
const traceJson = JSON.parse(
fs.readFileSync(outputFile, {encoding: 'utf8' }),
);
expect(traceJson.traceEvents).toContainEqual(
expect.objectContaining({
cat: 'toplevel' ,
}),
);
});
it('should throw if tracing on two pages' , async () => {
const {page, browser} = testState;
await page.tracing.start({path: outputFile});
const newPage = await browser.newPage();
let error!: Error;
await newPage.tracing.start({path: outputFile}).catch (error_ => {
return (error = error_);
});
await newPage.close();
expect(error).toBeTruthy();
await page.tracing.stop();
});
it('should return a typedArray' , async () => {
const {page, server} = testState;
await page.tracing.start({screenshots: true , path: outputFile});
await page.goto (server.PREFIX + '/grid.html' );
const trace = (await page.tracing.stop())!;
const buf = fs.readFileSync(outputFile);
expect(trace).toBeInstanceOf(Uint8Array);
expect(Buffer.from(trace).toString()).toEqual(buf.toString());
});
it('should work without options' , async () => {
const {page, server} = testState;
await page.tracing.start();
await page.goto (server.PREFIX + '/grid.html' );
const trace = await page.tracing.stop();
expect(trace).toBeTruthy();
});
it('should support a typedArray without a path' , async () => {
const {page, server} = testState;
await page.tracing.start();
await page.goto (server.PREFIX + '/grid.html' );
const trace = (await page.tracing.stop())!;
expect(Buffer.from(trace).toString().length).toBeGreaterThan(10 );
});
it('should properly fail if readProtocolStream errors out' , async () => {
const {page} = testState;
await page.tracing.start({path: import .meta.dirname});
let error!: Error;
try {
await page.tracing.stop();
} catch (error_) {
error = error_ as Error;
}
expect(error).toBeDefined();
});
});
Messung V0.5 in Prozent C=99 H=78 G=88
¤ Dauer der Verarbeitung: 0.19 Sekunden
(vorverarbeitet am 2026-10-04)
¤
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