add file logging, readme, so on

README.md

@@ -0,0 +1,181 @@
+# @atums/echo
+
+A minimal, flexible logger for Node with:
+
+- Colored console output
+- Daily `.jsonl` file logging
+- Configurable output patterns
+- Structured logs with caller metadata
+- Fully typed config with environment/file/constructor override
+
+---
+
+## Features
+
+- Console and file logging with level-based filtering
+- Colored output with ANSI formatting
+- Daily rotated `.jsonl` files
+- Supports runtime configuration merging
+- Auto-formatted output using custom patterns
+- Includes caller file, line, and column
+- Pretty-prints structured objects if enabled
+- Flushes open file streams on exit
+- Uses Biome and EditorConfig for formatting and linting
+
+---
+
+## Installation
+
+```bash
+bun add @atums/echo
+```
+
+---
+
+## Usage
+
+```ts
+import { echo } from "@atums/echo";
+
+echo.info("App started");
+echo.debug({ state: "init", ok: true });
+
+try {
+	throw new Error("Something failed");
+} catch (err) {
+	echo.error(err);
+}
+```
+
+---
+
+## Configuration
+
+Logger config can be defined in three ways:
+
+1. JSON file (e.g. `logger.json`)
+2. Environment variables
+3. Constructor override
+
+Priority (highest to lowest):
+
+```
+constructor > environment > logger.json > defaults
+```
+
+---
+
+### logger.json example
+
+```json
+{
+  "directory": "logs",
+  "level": "debug",
+  "console": true,
+  "consoleColor": true,
+  "rotate": true,
+  "maxFiles": 3,
+  "prettyPrint": true,
+  "pattern": "{color:gray}{timestamp}{reset} {color:levelColor}[{level-name}]{reset} ({file-name}:{line}:{column}) {data}"
+}
+```
+
+---
+
+### Supported Environment Variables
+
+| Variable              | Description                              |
+|------------------------|------------------------------------------|
+| `LOG_LEVEL`            | Log level (`debug`, `info`, etc.)        |
+| `LOG_DIRECTORY`        | Log directory path (default: `logs`)     |
+| `LOG_DISABLE_FILE`     | Disable file output (`true` or `false`)  |
+| `LOG_ROTATE`           | Enable daily rotation                    |
+| `LOG_MAX_FILES`        | Max rotated files to keep                |
+| `LOG_CONSOLE`          | Enable console output                    |
+| `LOG_CONSOLE_COLOR`    | Enable ANSI color in console output      |
+| `LOG_DATE_FORMAT`      | Date format for display timestamp        |
+| `LOG_TIMEZONE`         | Timezone (`local` or IANA string)        |
+| `LOG_SILENT`           | Completely disable output                |
+| `LOG_PATTERN`          | Custom log format for console            |
+| `LOG_PRETTY_PRINT`     | Pretty-print objects in console output   |
+
+---
+
+## Pattern Tokens
+
+These tokens are replaced in the log pattern:
+
+| Token         | Description                             |
+|---------------|-----------------------------------------|
+| `{timestamp}` | Formatted display timestamp             |
+| `{level-name}`| Uppercase log level (e.g. DEBUG)        |
+| `{level}`     | Numeric log level                       |
+| `{file-name}` | Source filename                         |
+| `{line}`      | Line number in source                   |
+| `{column}`    | Column number in source                 |
+| `{data}`      | Formatted log data (message/object)     |
+| `{id}`        | Unique short ID for the log             |
+| `{color:*}`   | ANSI color start (e.g. `{color:red}`)   |
+| `{reset}`     | Resets console color                    |
+
+---
+
+## Output Examples
+
+### Console (with colors)
+
+```
+2025-05-24 16:15:00.000 [INFO] (index.ts:3:6) Server started
+```
+
+### File (`logs/2025-05-24.jsonl`)
+
+Each line is structured JSON:
+
+```json
+{
+  "timestamp": 1748115300000,
+  "level": "info",
+  "id": "aB4cD9xZ",
+  "file": "index.ts",
+  "line": "3",
+  "column": "6",
+  "data": "Server started"
+}
+```
+
+If an error is logged:
+
+```json
+{
+  "timestamp": 1748115301000,
+  "level": "error",
+  "id": "qW3eR7tU",
+  "file": "index.ts",
+  "line": "10",
+  "column": "12",
+  "data": {
+    "name": "Error",
+    "message": "Something failed",
+    "stack": "Error: Something failed\n  at index.ts:10:12"
+  }
+}
+```
+
+---
+
+## Development
+
+This project uses:
+
+- TypeScript
+- Bun runtime
+- Biome for formatting/linting
+- JSONL for structured file output
+- `date-fns-tz` for timezone support
+
+---
+
+## License
+
+BSD 3-Clause [License](License)

src/index.ts

@@ -7,13 +7,14 @@ import {
 	statSync,
 } from "node:fs";
 import { resolve } from "node:path";
-import { parsePattern } from "@lib/char";
+import { getCallerInfo, parsePattern } from "@lib/char";
 import {
 	defaultConfig,
 	loadEnvConfig,
 	loadLoggerConfig,
 	logLevelValues,
 } from "@lib/config";
+import { writeLogJson } from "@lib/file";
 import type { LogLevel, LoggerConfig } from "@types";
 
 class Echo {
@@ -73,6 +74,7 @@ class Echo {
 		)
 			return;
 
+		const meta = getCallerInfo(this.config);
 		const line = parsePattern({ level, data, config: this.config });
 
 		if (this.config.console) {
@@ -80,6 +82,10 @@ class Echo {
 				line,
 			);
 		}
+
+		if (!this.config.disableFile) {
+			writeLogJson(level, data, meta, this.config);
+		}
 	}
 
 	public debug(data: unknown): void {

src/lib/char.ts

@@ -1,8 +1,8 @@
 import { basename } from "node:path";
-import { format } from "node:util";
+import { format, inspect } from "node:util";
 import { format as formatDate } from "date-fns-tz";
 
-import { ansiColors, logLevelValues } from "@lib/config";
+import { ansiColors, defaultLevelColor, logLevelValues } from "@lib/config";
 import type {
 	LogLevel,
 	LogLevelValue,
@@ -10,28 +10,43 @@ import type {
 	PatternContext,
 } from "@types";
 
-function getTimestamp(config: Required<LoggerConfig>): string {
+function getTimestamp(config: Required<LoggerConfig>): {
+	prettyTimestamp: string;
+	timestamp: string;
+} {
 	const now = new Date();
 
 	if (config.timezone === "local") {
-		return formatDate(now, config.dateFormat);
+		return {
+			prettyTimestamp: formatDate(now, config.dateFormat),
+			timestamp: now.toISOString(),
+		};
 	}
 
-	return formatDate(now, config.dateFormat, {
-		timeZone: config.timezone,
-	});
+	return {
+		prettyTimestamp: formatDate(now, config.dateFormat, {
+			timeZone: config.timezone,
+		}),
+		timestamp: now.toISOString(),
+	};
 }
 
 function getCallerInfo(config: Required<LoggerConfig>): {
+	id: string;
 	fileName: string;
 	line: string;
 	column: string;
 	timestamp: string;
+	prettyTimestamp: string;
 } {
+	const id = generateShortId();
+
 	const fallback = {
+		id: id,
 		fileName: "unknown",
 		line: "0",
-		timestamp: getTimestamp(config),
+		timestamp: getTimestamp(config).timestamp,
+		prettyTimestamp: getTimestamp(config).prettyTimestamp,
 		column: "0",
 	};
 
@@ -54,10 +69,12 @@ function getCallerInfo(config: Required<LoggerConfig>): {
 			const columnNumber = fileURLMatch[3];
 
 			return {
+				id: id,
 				fileName: basename(fullPath),
 				line: lineNumber,
 				column: columnNumber,
-				timestamp: getTimestamp(config),
+				timestamp: getTimestamp(config).timestamp,
+				prettyTimestamp: getTimestamp(config).prettyTimestamp,
 			};
 		}
 
@@ -76,10 +93,12 @@ function getCallerInfo(config: Required<LoggerConfig>): {
 			}
 
 			return {
+				id: id,
 				fileName: basename(fullPath),
 				line: lineNumber,
 				column: columnNumber,
-				timestamp: getTimestamp(config),
+				timestamp: getTimestamp(config).timestamp,
+				prettyTimestamp: getTimestamp(config).prettyTimestamp,
 			};
 		}
 	}
@@ -107,33 +126,45 @@ function replaceColorTokens(
 ): string {
 	return input
 		.replace(/{color:(\w+)}/g, (_, colorKey) => {
+			if (!config.consoleColor) return "";
 			if (colorKey === "levelColor") {
-				const colorForLevel = config.levelColor?.[level];
+				const colorForLevel =
+					config.levelColor?.[level] ?? defaultLevelColor[level];
 				return ansiColors[colorForLevel ?? ""] ?? "";
 			}
 			return ansiColors[colorKey] ?? "";
 		})
-		.replace(/{reset}/g, ansiColors.reset);
+		.replace(/{reset}/g, config.consoleColor ? ansiColors.reset : "");
 }
 
 function parsePattern(ctx: PatternContext): string {
 	const { level, data, config } = ctx;
 
-	const { fileName, line, column, timestamp } = getCallerInfo(config);
-	const resolvedData: string = format(data);
+	const { id, fileName, line, column, timestamp, prettyTimestamp } =
+		getCallerInfo(config);
+	const resolvedData: string =
+		config.prettyPrint && typeof data === "object" && data !== null
+			? inspect(data, {
+					depth: null,
+					colors: false,
+					breakLength: 1,
+					compact: false,
+				})
+			: format(data);
+
 	const numericLevel: LogLevelValue = logLevelValues[level];
 
-	const final: string = config.pattern
-		.replace(/{timestamp}/g, timestamp)
+	const final = config.pattern
+		.replace(/{timestamp}/g, config.prettyPrint ? prettyTimestamp : timestamp)
 		.replace(/{level-name}/g, level.toUpperCase())
 		.replace(/{level}/g, String(numericLevel))
 		.replace(/{file-name}/g, fileName)
 		.replace(/{line}/g, line)
 		.replace(/{data}/g, resolvedData)
-		.replace(/{id}/g, generateShortId())
+		.replace(/{id}/g, id)
 		.replace(/{column}/g, column);
 
-	return config.consoleColor ? replaceColorTokens(final, level, config) : final;
+	return replaceColorTokens(final, level, config);
 }
 
-export { parsePattern };
+export { parsePattern, getCallerInfo };

src/lib/config.ts

@@ -12,6 +12,16 @@ const logLevelValues = {
 	silent: 70,
 };
 
+const defaultLevelColor: Record<LogLevel, keyof typeof ansiColors> = {
+	trace: "cyan",
+	debug: "blue",
+	info: "green",
+	warn: "yellow",
+	error: "red",
+	fatal: "red",
+	silent: "gray",
+};
+
 const ansiColors: Record<string, string> = {
 	reset: "\x1b[0m",
 	dim: "\x1b[2m",
@@ -33,7 +43,6 @@ const defaultConfig: Required<LoggerConfig> = {
 	disableFile: false,
 
 	rotate: true,
-	maxSizeMB: 5,
 	maxFiles: 3,
 
 	console: true,
@@ -55,6 +64,8 @@ const defaultConfig: Required<LoggerConfig> = {
 		error: "red",
 		fatal: "red",
 	},
+
+	prettyPrint: true,
 };
 
 function loadLoggerConfig(configPath = "logger.json"): LoggerConfig {
@@ -75,8 +86,6 @@ function loadEnvConfig(): LoggerConfig {
 	if (process.env.LOG_DISABLE_FILE)
 		config.disableFile = process.env.LOG_DISABLE_FILE === "true";
 	if (process.env.LOG_ROTATE) config.rotate = process.env.LOG_ROTATE === "true";
-	if (process.env.LOG_MAX_SIZE_MB)
-		config.maxSizeMB = Number.parseInt(process.env.LOG_MAX_SIZE_MB, 10);
 	if (process.env.LOG_MAX_FILES)
 		config.maxFiles = Number.parseInt(process.env.LOG_MAX_FILES, 10);
 	if (process.env.LOG_CONSOLE)
@@ -88,12 +97,15 @@ function loadEnvConfig(): LoggerConfig {
 	if (process.env.LOG_TIMEZONE) config.timezone = process.env.LOG_TIMEZONE;
 	if (process.env.LOG_SILENT) config.silent = process.env.LOG_SILENT === "true";
 	if (process.env.LOG_PATTERN) config.pattern = process.env.LOG_PATTERN;
+	if (process.env.LOG_PRETTY_PRINT)
+		config.prettyPrint = process.env.LOG_PRETTY_PRINT === "true";
 
 	return config;
 }
 
 export {
 	defaultConfig,
+	defaultLevelColor,
 	loadLoggerConfig,
 	loadEnvConfig,
 	logLevelValues,

src/lib/file.ts

@@ -0,0 +1,105 @@
+import {
+	type WriteStream,
+	createWriteStream,
+	existsSync,
+	mkdirSync,
+} from "node:fs";
+import { join } from "node:path";
+import type { LogLevel, LoggerConfig } from "@types";
+import { format } from "date-fns-tz";
+
+let currentStream: WriteStream | null = null;
+let currentFilePath = "";
+let currentDate = "";
+
+function getLogFilePath(
+	config: Required<LoggerConfig>,
+	dateStr: string,
+): string {
+	return join(config.directory, `${dateStr}.jsonl`);
+}
+
+function resetStream(path: string): void {
+	currentStream?.end();
+	currentStream = createWriteStream(path, { flags: "a", encoding: "utf-8" });
+	currentFilePath = path;
+}
+
+export function writeLogJson(
+	level: LogLevel,
+	data: unknown,
+	meta: {
+		id: string;
+		fileName: string;
+		line: string;
+		column: string;
+		timestamp: string;
+		prettyTimestamp: string;
+	},
+	config: Required<LoggerConfig>,
+): void {
+	if (config.disableFile) return;
+
+	const now = new Date();
+
+	if (!existsSync(config.directory)) {
+		mkdirSync(config.directory, { recursive: true });
+	}
+
+	let filePath: string;
+
+	if (config.rotate) {
+		const dateStr = format(now, "yyyy-MM-dd", {
+			timeZone: config.timezone,
+		});
+		filePath = getLogFilePath(config, dateStr);
+
+		if (
+			currentStream === null ||
+			currentFilePath !== filePath ||
+			currentDate !== dateStr
+		) {
+			currentDate = dateStr;
+			resetStream(filePath);
+		}
+	} else {
+		filePath = join(config.directory, "log.jsonl");
+
+		if (currentStream === null || currentFilePath !== filePath) {
+			resetStream(filePath);
+		}
+	}
+
+	const line = `${JSON.stringify({
+		timestamp: new Date(meta.timestamp).getTime(),
+		level,
+		id: meta.id,
+		file: meta.fileName,
+		line: meta.line,
+		column: meta.column,
+		data:
+			data instanceof Error
+				? {
+						name: data.name,
+						message: data.message,
+						stack: data.stack,
+					}
+				: typeof data === "string" || typeof data === "number"
+					? data
+					: data,
+	})}\n`;
+
+	if (currentStream === null) {
+		throw new Error("Logger stream is not initialized");
+	}
+
+	currentStream.write(line);
+}
+
+process.on("exit", () => {
+	currentStream?.end();
+});
+process.on("SIGINT", () => {
+	currentStream?.end();
+	process.exit();
+});

types/index.ts

@@ -9,7 +9,6 @@ type LoggerConfig = {
 	disableFile?: boolean;
 
 	rotate?: boolean;
-	maxSizeMB?: number;
 	maxFiles?: number;
 
 	console?: boolean;
@@ -22,6 +21,8 @@ type LoggerConfig = {
 
 	pattern?: string;
 	levelColor?: Partial<Record<LogLevel, keyof typeof ansiColors>>;
+
+	prettyPrint?: boolean;
 };
 
 interface PatternContext {