fix: forward backend logging to electron

.vscode/tasks.json

@@ -4,8 +4,11 @@
     {
       "label": "Rebuild App",
       "type": "shell",
-      "command": "yarn rebuild:browser && yarn rebuild:electron",
+      "command": "yarn rebuild",
       "group": "build",
+      "options": {
+        "cwd": "${workspaceFolder}/electron-app"
+      },
       "presentation": {
         "reveal": "always",
         "panel": "new",

arduino-ide-extension/src/electron-main/theia/electron-main-application.ts

@@ -1,35 +1,33 @@
-import { inject, injectable } from '@theia/core/shared/inversify';
+import type { FrontendApplicationConfig } from '@theia/application-package/lib/application-props';
+import { environment } from '@theia/application-package/lib/environment';
 import {
   app,
   BrowserWindow,
   contentTracing,
-  ipcMain,
   Event as ElectronEvent,
+  ipcMain,
 } from '@theia/core/electron-shared/electron';
-import { fork } from 'node:child_process';
-import { AddressInfo } from 'node:net';
-import { join, isAbsolute, resolve } from 'node:path';
-import { promises as fs, rm, rmSync } from 'node:fs';
-import type { MaybePromise, Mutable } from '@theia/core/lib/common/types';
+import {
+  Disposable,
+  DisposableCollection,
+} from '@theia/core/lib/common/disposable';
+import { isOSX } from '@theia/core/lib/common/os';
+import { Deferred } from '@theia/core/lib/common/promise-util';
+import { isObject, MaybePromise, Mutable } from '@theia/core/lib/common/types';
 import { ElectronSecurityToken } from '@theia/core/lib/electron-common/electron-token';
-import { FrontendApplicationConfig } from '@theia/application-package/lib/application-props';
-import { environment } from '@theia/application-package/lib/environment';
 import {
   ElectronMainApplication as TheiaElectronMainApplication,
   ElectronMainExecutionParams,
 } from '@theia/core/lib/electron-main/electron-main-application';
-import { URI } from '@theia/core/shared/vscode-uri';
-import { Deferred } from '@theia/core/lib/common/promise-util';
-import * as os from '@theia/core/lib/common/os';
-import { TheiaBrowserWindowOptions } from '@theia/core/lib/electron-main/theia-electron-window';
-import { IsTempSketch } from '../../node/is-temp-sketch';
-import { ErrnoException } from '../../node/utils/errors';
-import { isAccessibleSketchPath } from '../../node/sketches-service-impl';
+import type { TheiaBrowserWindowOptions } from '@theia/core/lib/electron-main/theia-electron-window';
 import { FileUri } from '@theia/core/lib/node/file-uri';
-import {
-  Disposable,
-  DisposableCollection,
-} from '@theia/core/lib/common/disposable';
+import { inject, injectable } from '@theia/core/shared/inversify';
+import { URI } from '@theia/core/shared/vscode-uri';
+import { log as logToFile, setup as setupFileLog } from 'node-log-rotate';
+import { fork } from 'node:child_process';
+import { promises as fs, rm, rmSync } from 'node:fs';
+import type { AddressInfo } from 'node:net';
+import { isAbsolute, join, resolve } from 'node:path';
 import { Sketch } from '../../common/protocol';
 import {
   AppInfo,
@@ -39,9 +37,71 @@ import {
   CHANNEL_SHOW_PLOTTER_WINDOW,
   isShowPlotterWindowParams,
 } from '../../electron-common/electron-arduino';
+import { IsTempSketch } from '../../node/is-temp-sketch';
+import { isAccessibleSketchPath } from '../../node/sketches-service-impl';
+import { ErrnoException } from '../../node/utils/errors';
 
 app.commandLine.appendSwitch('disable-http-cache');
 
+const consoleLogFunctionNames = [
+  'log',
+  'trace',
+  'debug',
+  'info',
+  'warn',
+  'error',
+] as const;
+type ConsoleLogSeverity = (typeof consoleLogFunctionNames)[number];
+interface ConsoleLogParams {
+  readonly severity: ConsoleLogSeverity;
+  readonly message: string;
+}
+function isConsoleLogParams(arg: unknown): arg is ConsoleLogParams {
+  return (
+    isObject<ConsoleLogParams>(arg) &&
+    typeof arg.message === 'string' &&
+    typeof arg.severity === 'string' &&
+    consoleLogFunctionNames.includes(arg.severity as ConsoleLogSeverity)
+  );
+}
+
+// Patch for on Linux when `XDG_CONFIG_HOME` is not available, `node-log-rotate` creates the folder with `undefined` name.
+// See https://github.com/lemon-sour/node-log-rotate/issues/23 and https://github.com/arduino/arduino-ide/issues/394.
+// If the IDE2 is running on Linux, and the `XDG_CONFIG_HOME` variable is not available, set it to avoid the `undefined` folder.
+// From the specs: https://specifications.freedesktop.org/basedir-spec/latest/ar01s03.html
+// "If $XDG_CONFIG_HOME is either not set or empty, a default equal to $HOME/.config should be used."
+function enableFileLogger() {
+  const os = require('os');
+  const util = require('util');
+  if (os.platform() === 'linux' && !process.env['XDG_CONFIG_HOME']) {
+    const { join } = require('path');
+    const home = process.env['HOME'];
+    const xdgConfigHome = home
+      ? join(home, '.config')
+      : join(os.homedir(), '.config');
+    process.env['XDG_CONFIG_HOME'] = xdgConfigHome;
+  }
+  setupFileLog({
+    appName: 'Arduino IDE',
+    maxSize: 10 * 1024 * 1024,
+  });
+  for (const name of consoleLogFunctionNames) {
+    const original = console[name];
+    console[name] = function () {
+      // eslint-disable-next-line prefer-rest-params
+      const messages = Object.values(arguments);
+      const message = util.format(...messages);
+      original(message);
+      logToFile(message);
+    };
+  }
+}
+
+const isProductionMode = !environment.electron.isDevMode();
+if (isProductionMode) {
+  enableFileLogger();
+}
+
 interface WorkspaceOptions {
   file: string;
   x: number;
@@ -185,7 +245,7 @@ export class ElectronMainApplication extends TheiaElectronMainApplication {
 
   private attachFileAssociations(cwd: string): void {
     // OSX: register open-file event
-    if (os.isOSX) {
+    if (isOSX) {
       app.on('open-file', async (event, path) => {
         event.preventDefault();
         const resolvedPath = await this.resolvePath(path, cwd);
@@ -495,9 +555,14 @@ export class ElectronMainApplication extends TheiaElectronMainApplication {
       );
       console.log(`Starting backend process. PID: ${backendProcess.pid}`);
       return new Promise((resolve, reject) => {
-        // The backend server main file is also supposed to send the resolved http(s) server port via IPC.
-        backendProcess.on('message', (address: AddressInfo) => {
-          resolve(address.port);
+        // The forked backend process sends the resolved http(s) server port via IPC, and forwards the log messages.
+        backendProcess.on('message', (arg: unknown) => {
+          if (isConsoleLogParams(arg)) {
+            const { message, severity } = arg;
+            console[severity](message);
+          } else if (isAddressInfo(arg)) {
+            resolve(arg.port);
+          }
         });
         backendProcess.on('error', (error) => {
           reject(error);
@@ -703,7 +768,7 @@ class InterruptWorkspaceRestoreError extends Error {
 async function updateFrontendApplicationConfigFromPackageJson(
   config: FrontendApplicationConfig
 ): Promise<FrontendApplicationConfig> {
-  if (environment.electron.isDevMode()) {
+  if (!isProductionMode) {
     console.debug(
       'Skipping frontend application configuration customizations. Running in dev mode.'
     );
@@ -777,3 +842,9 @@ function updateAppInfo(
   });
   return toUpdate;
 }
+
+function isAddressInfo(arg: unknown): arg is Pick<AddressInfo, 'port'> {
+  // Cannot do the type-guard on all properties, but the port is sufficient as the address is always `localhost`.
+  // For example, the `family` might be absent if the address is IPv6.
+  return isObject<AddressInfo>(arg) && typeof arg.port === 'number';
+}

electron-app/arduino-ide-backend-main.js

@@ -1,42 +1,17 @@
 // @ts-check
 'use strict';
 
-// Patch for on Linux when `XDG_CONFIG_HOME` is not available, `node-log-rotate` creates the folder with `undefined` name.
-// See https://github.com/lemon-sour/node-log-rotate/issues/23 and https://github.com/arduino/arduino-ide/issues/394.
-// If the IDE2 is running on Linux, and the `XDG_CONFIG_HOME` variable is not available, set it to avoid the `undefined` folder.
-// From the specs: https://specifications.freedesktop.org/basedir-spec/latest/ar01s03.html
-// "If $XDG_CONFIG_HOME is either not set or empty, a default equal to $HOME/.config should be used."
-function enableFileLogger() {
-  const os = require('os');
+// `true` if the this (backend main) process has been forked.
+if (process.send) {
   const util = require('util');
-  if (os.platform() === 'linux' && !process.env['XDG_CONFIG_HOME']) {
-    const { join } = require('path');
-    const home = process.env['HOME'];
-    const xdgConfigHome = home
-      ? join(home, '.config')
-      : join(os.homedir(), '.config');
-    process.env['XDG_CONFIG_HOME'] = xdgConfigHome;
-  }
-  const { setup, log } = require('node-log-rotate');
-
-  setup({
-    appName: 'Arduino IDE',
-    maxSize: 10 * 1024 * 1024,
-  });
   for (const name of ['log', 'trace', 'debug', 'info', 'warn', 'error']) {
-    const original = console[name];
     console[name] = function () {
       // eslint-disable-next-line prefer-rest-params
-      const messages = Object.values(arguments);
-      const message = util.format(...messages);
-      original(message);
-      log(message);
+      const args = Object.values(arguments);
+      const message = util.format(...args);
+      process.send?.({ severity: name, message }); // send the log message to the parent process (electron main)
     };
   }
 }
 
-if (process.env.IDE2_FILE_LOGGER === 'true') {
-  enableFileLogger();
-}
-
 require('./src-gen/backend/main');

electron-app/arduino-ide-electron-main.js

@@ -18,8 +18,6 @@ if (config.buildDate) {
   ]
     .filter(Boolean)
     .join(',');
-  // Enables the file logger in the backend process.
-  process.env.IDE2_FILE_LOGGER = 'true';
 }
 
 require('./lib/backend/electron-main');

electron-app/package.json

@@ -53,7 +53,7 @@
     "prepackage": "rimraf dist",
     "package": "node ./scripts/package.js",
     "postpackage": "node ./scripts/post-package.js",
-    "rebuild": "theia rebuild:browser && theia rebuild:electron"
+    "rebuild": "theia rebuild:browser --cacheRoot ../.. && theia rebuild:electron --cacheRoot ../.."
   },
   "theia": {
     "target": "electron",