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Console

Designed based on the Web APIs standard Console API. The edge function runtime can use the console object to output debugging information and logs. The output content can be viewed and analyzed through web debugging operations, or the real-time log push feature can be used to achieve long-term log retention and query analysis.

Description

console.log(val1)
console.log(val1, /* …, */ valN)
console object's other methods (info(), notice(), warn(), error(), debug()) have the same syntax format.

Parameter

Parameter Name
Type
Required
Description
val1
string | number | null | undefined | boolean | object | Symbol | Array<[string, string]> | Function
No
The first value to output.
valN
string | number | null | undefined | boolean | object | Symbol | Array<[string, string]> | Function
No
Other values to output.
Note:
In edge functions, the content output by console can be retained and analyzed through the real-time log push feature for long-term log retention and query analysis.
1. In Function logs, console supports four levels: info, notice, warn, and error. console.log() corresponds to the info level.
2. In edge functions, custom log output content other than log, info, notice, warn, and error will not be recorded in Function logs.
3. The size limit for a single real-time log is 40KB, and the console output content size limit is 4KB. Exceeding the limit will result in truncation.
Note:
1. In a single edge function, it is recommended to limit each console content length to 8k characters.
2. In a single edge function, the Web debugging page displays a maximum of 20 console outputs per request. Any console output exceeding 20 will not be shown on the debugging page.

Example Code

function handleEvent(event) {
  const { request } = event;
  const url = new URL(request.url);

  // Output basic information
  console.log('Process request:', url.pathname);

  // Output prompt message
  console.info('Request processing started');

  // Output attention information
  console.notice('Request processing method:', request.method);

  // Output warning information
  console.warn('Request parameters may be incomplete');

  // Output error information
  console.error('Error occurred while processing the request');

  return event.respondWith(new Response('Hello World'));
}

addEventListener('fetch', event => {
  handleEvent(event);
});

Sample Preview



Related Reference

MDN official documentation: console
Operation guide: Web debugging
Cloud Log Service (CLS)
Edge Function logs