Why is my Playwright logger not capturing output correctly?

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1

I’m working on a project using Playwright for automated testing on Windows 10 with Node.js version 16. I intended to capture and log detailed test execution data using the Playwright logger method. I’ve set up my environment and attempted to configure the logger according to the documentation, but I’m not seeing any output in my logs. I expected detailed logs during test runs, but the log file remains empty or only partially filled. Any insights into what might be going wrong? How can I correctly use the logger method in Playwright?

2

This kind of logging issue is something I’ve encountered a few times. It often happens when the Playwright logger is not configured or passed correctly when launching the browser.

Playwright’s logger must be defined in the browser launch configuration, including both the logging condition and the output function. If the logger isn’t initialized properly, Playwright won’t produce any log output.

Here is a simple configuration that worked for me:

const { chromium } = require('playwright');

(async () => {
  const browser = await chromium.launch({
    logger: {
      isEnabled: (name, severity) => severity === 'warning' || severity === 'error',
      log: (name, severity, message) =>
        console.log(`[${name}] ${severity}: ${message}`)
    }
  });
})();

This configuration captures warnings and errors and prints them to the console.

Make sure the isEnabled function actually allows the log levels you want to capture. If it filters out all levels, the logger will appear silent. Also confirm that the logger object is provided before launching the browser.

3

I ran into something similar when setting up logging with Playwright. In my case, the issue was related to how logs were written and persisted.

Instead of printing logs to the console, you can write them directly to a file to ensure nothing gets lost during execution.

For example:

const { chromium } = require('playwright');

(async () => {
  const logger = {
    isEnabled: (name, severity) => true,
    log: (name, severity, message) =>
      require('fs').appendFileSync(
        'playwright.log',
        `[${name}] ${severity}: ${message}\n`
      )
  };

  const browser = await chromium.launch({ logger });
})();

This configuration captures all log levels and appends them to a file.

If you’re logging to a file, make sure the file path is valid and the process has permission to write to it. File permission issues or incorrect paths are common reasons logs fail to appear.