Extract logger and write to file

Summary:
This change extracts logging logic out from startFlipperServer.

Logs will also be written to disk.

Reviewed By: passy

Differential Revision: D36473768

fbshipit-source-id: b1df9df79b4aced0d3ba2e8c243aa8d44cf83703

desktop/flipper-server/src/index.tsx

@@ -14,6 +14,7 @@ import {startFlipperServer} from './startFlipperServer';
 import {startServer} from './startServer';
 import {attachSocketServer} from './attachSocketServer';
 import {attachDevServer} from './attachDevServer';
+import {initializeLogger} from './logger';
 
 import yargs from 'yargs';
 import open from 'open';
@@ -72,10 +73,7 @@ const rootDir = argv.bundler
 const staticDir = path.join(rootDir, 'static');
 
 async function start() {
-  // supress debug messages by default. TODO: make CLI flag
+  initializeLogger(staticDir);
-  console.debug = function () {
-    // Noop
-  };
 
   const {app, server, socket} = await startServer({
     port: argv.port,

desktop/flipper-server/src/logger.tsx

@@ -0,0 +1,95 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import * as fs from 'fs-extra';
+import path from 'path';
+import {
+  LoggerExtractError,
+  LoggerFormat,
+  LoggerInfo,
+  LoggerTypes,
+  Logger,
+  setLoggerInstance,
+} from 'flipper-common';
+
+export const loggerOutputFile = 'flipper-server-log.out';
+
+const logTypes: LoggerTypes[] = ['debug', 'info', 'warn', 'error'];
+
+function createLogger(): Logger {
+  return {
+    track(..._args: [any, any, any?, any?]) {
+      // TODO: only if verbose console.debug(...args);
+      // console.warn('(skipper track)', args);
+    },
+    trackTimeSince(..._args: [any, any, any?]) {
+      // TODO: only if verbose console.debug(...args);
+      // console.warn('(skipped trackTimeSince)', args);
+    },
+    debug(...args: any[]) {
+      console.debug(...args);
+    },
+    error(...args: any[]) {
+      console.error(...args);
+    },
+    warn(...args: any[]) {
+      console.warn(...args);
+    },
+    info(...args: any[]) {
+      console.info(...args);
+    },
+  };
+}
+
+type FlipperLogProxy = (entry: LoggerInfo) => void;
+
+const consoleProxy = (proxy: FlipperLogProxy) => {
+  function log(level: LoggerTypes, ...data: Array<any>): void {
+    const logInfo = LoggerFormat(level, ...data);
+    proxy(logInfo);
+
+    if (level === 'error') {
+      const {
+        message,
+        error: {stack, interaction, name},
+      } = LoggerExtractError(data);
+      const logInfo = LoggerFormat(level, {
+        name,
+        stack,
+        interaction,
+        message,
+      });
+      proxy(logInfo);
+    }
+  }
+
+  for (const method of logTypes) {
+    const originalConsole: {[key: string]: any} = console;
+    const originalMethod = originalConsole[method];
+    const overrideMethod = (...args: Array<unknown>) => {
+      const result = originalMethod(...args);
+      log(method, ...args);
+      return result;
+    };
+    originalConsole[method] = overrideMethod;
+  }
+};
+
+export function initializeLogger(staticDir: string) {
+  // Supress debug messages by default.
+  console.debug = function () {};
+
+  const logger = createLogger();
+  setLoggerInstance(logger);
+
+  const file = fs.createWriteStream(path.join(staticDir, loggerOutputFile));
+  consoleProxy((entry: LoggerInfo) => {
+    file.write(`${JSON.stringify(entry)}\n`);
+  });
+}

desktop/flipper-server/src/startFlipperServer.tsx

@@ -16,12 +16,7 @@ import {
   loadSettings,
   getEnvironmentInfo,
 } from 'flipper-server-core';
-import {
+import {parseEnvironmentVariables, isTest, getLogger} from 'flipper-common';
-  parseEnvironmentVariables,
-  isTest,
-  Logger,
-  setLoggerInstance,
-} from 'flipper-common';
 import path from 'path';
 import fs from 'fs-extra';
 
@@ -53,9 +48,6 @@ export async function startFlipperServer(
     desktopPath = os.homedir();
   }
 
-  const logger = createLogger();
-  setLoggerInstance(logger);
-
   let keytar: any = undefined;
   try {
     if (!isTest()) {
@@ -96,35 +88,7 @@ export async function startFlipperServer(
       settings: await loadSettings(settingsString),
       validWebSocketOrigins: ['localhost:', 'http://localhost:'],
     },
-    logger,
+    getLogger(),
     keytar,
   );
 }
-
-function createLogger(): Logger {
-  return {
-    track(..._args: [any, any, any?, any?]) {
-      // TODO: only if verbose console.debug(...args);
-      // console.warn('(skipper track)', args);
-    },
-    trackTimeSince(..._args: [any, any, any?]) {
-      // TODO: only if verbose console.debug(...args);
-      // console.warn('(skipped trackTimeSince)', args);
-    },
-    debug(..._args: any[]) {
-      // TODO: only if double verbose console.debug(...args);
-    },
-    error(...args: any[]) {
-      console.error(...args);
-      console.warn('(skipped error reporting)');
-    },
-    warn(...args: any[]) {
-      console.warn(...args);
-      console.warn('(skipped error reporting)');
-    },
-    info(..._args: any[]) {
-      // TODO: only if  verbose console.debug(...args);
-      // console.info(...args);
-    },
-  };
-}