Frontend global loggers (#192)

* frontend logging added

.prettierrc.js

@@ -0,0 +1 @@
+// intentionally blank

src-electron/main-process/electron-main.js

@@ -26,7 +26,11 @@ let installUpdate = false;
 
 const title = `${productName} v${version}`;
 
-const selectionMenu = Menu.buildFromTemplate([{ role: "copy" }, { type: "separator" }, { role: "selectall" }]);
+const selectionMenu = Menu.buildFromTemplate([
+  { role: "copy" },
+  { type: "separator" },
+  { role: "selectall" }
+]);
 
 const inputMenu = Menu.buildFromTemplate([
   { role: "cut" },
@@ -54,7 +58,13 @@ function createWindow() {
     minWidth: 640,
     minHeight: 480,
     icon: require("path").join(__statics, "icon_512x512.png"),
-    title
+    title,
+    webPreferences: {
+      nodeIntegration: true,
+      nodeIntegrationInWorker: true,
+      // anything we want preloaded, e.g. global vars
+      preload: path.resolve(__dirname, "electron-preload.js")
+    }
   });
 
   mainWindow.on("close", e => {

src-electron/main-process/electron-preload.js

@@ -0,0 +1,3 @@
+const path = require("upath");
+
+require(path.resolve(__dirname, "logging.js"));

src-electron/main-process/logging.js

@@ -0,0 +1,78 @@
+// This allows for logging (to a file) from the frontend by creating global logging functions
+// That send ipc calls (from renderer) to the electron main process
+// create global logging functions for the frontend. It sends messages to the main
+// process which then log to file
+
+const electron = require("electron");
+
+const _ = require("lodash");
+
+const ipc = electron.ipcRenderer;
+
+function log(...args) {
+  logAtLevel("info", "INFO ", ...args);
+}
+
+if (window.console) {
+  console._log = console.log;
+  console.log = log;
+  console._trace = console.trace;
+  console._debug = console.debug;
+  console._info = console.info;
+  console._warn = console.warn;
+  console._error = console.error;
+  console._fatal = console.error;
+}
+
+// To avoid [Object object] in our log since console.log handles non-strings
+// smoothly
+function cleanArgsForIPC(args) {
+  const str = args.map(item => {
+    if (typeof item !== "string") {
+      try {
+        return JSON.stringify(item);
+      } catch (error) {
+        return item;
+      }
+    }
+
+    return item;
+  });
+
+  return str.join(" ");
+}
+
+// Backwards-compatible logging, simple strings and no level (defaulted to INFO)
+function now() {
+  const date = new Date();
+  return date.toJSON();
+}
+
+// The Bunyan API: https://github.com/trentm/node-bunyan#log-method-api
+function logAtLevel(level, prefix, ...args) {
+  const fn = `_${level}`;
+  console[fn](prefix, now(), ...args);
+
+  const logText = cleanArgsForIPC(args);
+  ipc.send(`log-${level}`, logText);
+}
+
+window.log = {
+  fatal: _.partial(logAtLevel, "fatal", "FATAL"),
+  error: _.partial(logAtLevel, "error", "ERROR"),
+  warn: _.partial(logAtLevel, "warn", "WARN "),
+  info: _.partial(logAtLevel, "info", "INFO "),
+  debug: _.partial(logAtLevel, "debug", "DEBUG"),
+  trace: _.partial(logAtLevel, "trace", "TRACE")
+};
+
+window.onerror = (message, script, line, col, error) => {
+  const errorInfo = error && error.stack ? error.stack : JSON.stringify(error);
+  window.log.error(`Top-level unhandled error: ${errorInfo}`);
+};
+
+window.addEventListener("unhandledrejection", rejectionEvent => {
+  const error = rejectionEvent.reason;
+  const errorInfo = error && error.stack ? error.stack : error;
+  window.log.error("Top-level unhandled promise rejection:", errorInfo);
+});

src-electron/main-process/modules/backend.js

@@ -8,11 +8,16 @@ import { version } from "../../../package.json";
 const bunyan = require("bunyan");
 
 const WebSocket = require("ws");
+const electron = require("electron");
 const os = require("os");
 const fs = require("fs-extra");
 const path = require("upath");
 const objectAssignDeep = require("object-assign-deep");
 
+const { ipcMain: ipc } = electron;
+
+const LOG_LEVELS = ["fatal", "error", "warn", "info", "debug", "trace"];
+
 export class Backend {
   constructor(mainWindow) {
     this.mainWindow = mainWindow;
@@ -355,12 +360,20 @@ export class Backend {
       name: "log",
       streams: [
         {
-          level: "debug",
-          path: path.join(logPath, "electron.log")
+          type: "rotating-file",
+          path: path.join(logPath, "electron.log"),
+          period: "1d", // daily rotation
+          count: 4 // keep 4 days of logs
         }
       ]
     });
 
+    LOG_LEVELS.forEach(level => {
+      ipc.on(`log-${level}`, (first, ...rest) => {
+        log[level](...rest);
+      });
+    });
+
     this.log = log;
 
     process.on("uncaughtException", error => {