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/**
* @license
* Copyright 2020 Google Inc.
* SPDX-License-Identifier: Apache-2.0
*/
import type Debug from 'debug';
import {isNode} from '../environment.js';
declare global {
const __PUPPETEER_DEBUG: string;
}
/**
* @internal
*/
let debugModule: typeof Debug | null = null;
/**
* @internal
*/
export async function importDebug(): Promise<typeof Debug> {
if (!debugModule) {
debugModule = (await import('debug')).default;
}
return debugModule;
}
/**
* A debug function that can be used in any environment.
*
* @remarks
* If used in Node, it falls back to the
* uses `console.log`.
*
* In Node, use the `DEBUG` environment variable to control logging:
*
* ```
* DEBUG=* // logs all channels
* DEBUG=foo // logs the `foo` channel
* DEBUG=foo* // logs any channels starting with `foo`
* ```
*
* In the browser, set `window.__PUPPETEER_DEBUG` to a string:
*
* ```
* window.__PUPPETEER_DEBUG='*'; // logs all channels
* window.__PUPPETEER_DEBUG='foo'; // logs the `foo` channel
* window.__PUPPETEER_DEBUG='foo*'; // logs any channels starting with `foo`
* ```
*
* @example
*
* ```
* const log = debug('Page');
*
* log('new page created')
* // logs "Page: new page created"
* ```
*
* @param prefix - this will be prefixed to each log.
* @returns a function that can be called to log to that debug channel.
*
* @internal
*/
export const debug = (prefix: string): ((...args: unknown[]) => void) => {
if (isNode) {
return async (...logArgs: unknown[]) => {
if (captureLogs) {
capturedLogs.push(prefix + logArgs);
}
(await importDebug())(prefix)(logArgs);
};
}
return (...logArgs: unknown[]): void => {
const debugLevel = (globalThis as any).__PUPPETEER_DEBUG;
if (!debugLevel) {
return;
}
const everythingShouldBeLogged = debugLevel === '*';
const prefixMatchesDebugLevel =
everythingShouldBeLogged ||
/**
* If the debug level is `foo*`, that means we match any prefix that
* starts with `foo`. If the level is `foo`, we match only the prefix
* `foo`.
*/
(debugLevel.endsWith('*')
? prefix.startsWith(debugLevel)
: prefix === debugLevel);
if (!prefixMatchesDebugLevel) {
return;
}
// eslint-disable-next-line no-console
console.log(`${prefix}:`, ...logArgs);
};
};
/**
* @internal
*/
let capturedLogs: string[] = [];
/**
* @internal
*/
let captureLogs = false;
/**
* @internal
*/
export function setLogCapture(value: boolean): void {
capturedLogs = [];
captureLogs = value;
}
/**
* @internal
*/
export function getCapturedLogs(): string[] {
return capturedLogs;
}