1 files changed, 136 insertions, 0 deletions
diff --git a/remote/test/puppeteer/packages/puppeteer-core/src/common/Debug.ts b/remote/test/puppeteer/packages/puppeteer-core/src/common/Debug.ts
new file mode 100644
index 0000000000..ae9ddab90d
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+++ b/remote/test/puppeteer/packages/puppeteer-core/src/common/Debug.ts
@@ -0,0 +1,136 @@
+/**
+ * Copyright 2020 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {isNode} from '../environment.js';
+
+declare global {
+  // eslint-disable-next-line no-var
+  var __PUPPETEER_DEBUG: string;
+}
+
+/**
+ * @internal
+ */
+let debugModule: typeof import('debug') | null = null;
+/**
+ * @internal
+ */
+export async function importDebug(): Promise<typeof import('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
+ * {@link https://www.npmjs.com/package/debug | debug module}. In the browser it
+ * 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;
+}