File size: 3,295 Bytes
9e4583c | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 | /**
* Console Log Interceptor — captures console output to a log file.
*
* Monkey-patches console.log, console.info, console.warn, console.error,
* and console.debug to also append JSON log entries to a file. This allows
* the Console Log Viewer to display application logs in real-time.
*
* Call initConsoleInterceptor() once at server startup (before any logging).
*
* @module lib/consoleInterceptor
*/
import { appendFileSync, existsSync, mkdirSync } from "fs";
import { dirname, resolve } from "path";
const logToFile = process.env.LOG_TO_FILE !== "false";
const logFilePath = resolve(process.env.LOG_FILE_PATH || "logs/application/app.log");
let initialized = false;
/**
* Map console method names to log levels.
*/
const LEVEL_MAP: Record<string, string> = {
debug: "debug",
log: "info",
info: "info",
warn: "warn",
error: "error",
};
/**
* Ensure the log directory exists.
*/
function ensureDir() {
const dir = dirname(logFilePath);
if (!existsSync(dir)) {
mkdirSync(dir, { recursive: true });
}
}
/**
* Try to extract component name from message patterns like [COMPONENT] or [component].
*/
function extractComponent(msg: string): string {
const match = msg.match(/^\[([^\]]+)\]/);
return match ? match[1] : "app";
}
/**
* Convert arguments to a string message, handling objects and errors.
*/
function argsToMessage(args: unknown[]): string {
return args
.map((arg) => {
if (arg instanceof Error) return `${arg.message}\n${arg.stack || ""}`;
if (typeof arg === "object" && arg !== null) {
try {
return JSON.stringify(arg);
} catch {
return String(arg);
}
}
return String(arg);
})
.join(" ");
}
/**
* Append a JSON log entry to the log file.
*/
function writeEntry(level: string, args: unknown[]) {
try {
const message = argsToMessage(args);
const entry = {
timestamp: new Date().toISOString(),
level,
component: extractComponent(message),
message,
};
appendFileSync(logFilePath, JSON.stringify(entry) + "\n");
} catch {
// Silently fail — never break the app over log writing
}
}
/**
* Initialize the console interceptor.
* Patches console.log, console.info, console.warn, console.error, console.debug
* to also write to the log file.
*
* Safe to call multiple times — only initializes once.
*/
export function initConsoleInterceptor(): void {
if (!logToFile || initialized) return;
try {
ensureDir();
} catch {
// Can't create log dir — skip interception
return;
}
initialized = true;
// Save original methods
const originalMethods = {
log: console.log.bind(console),
info: console.info.bind(console),
warn: console.warn.bind(console),
error: console.error.bind(console),
debug: console.debug.bind(console),
};
// Patch each console method
for (const [method, level] of Object.entries(LEVEL_MAP)) {
const original = originalMethods[method as keyof typeof originalMethods];
if (!original) continue;
(console as unknown as Record<string, unknown>)[method] = (...args: unknown[]) => {
// Call original console method
original(...args);
// Also write to file
writeEntry(level, args);
};
}
}
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