refactor: remove global Logger instance (#40)

src/cli.ts

@@ -8,7 +8,7 @@ import { CLIArgs, parseArgs } from './args.js';
 import { CLI_OPTIONS, HOSTS_LOCAL, HOSTS_WILDCARD } from './constants.js';
 import { checkDirAccess, readPkgJson } from './fs-utils.js';
 import { RequestHandler } from './handler.js';
-import { color, logger, requestLogLine } from './logger.js';
+import { color, Logger, requestLogLine } from './logger.js';
 import { serverOptions } from './options.js';
 import { FileResolver } from './resolver.js';
 import type { OptionName, ServerOptions } from './types.d.ts';
@@ -18,6 +18,7 @@ import { clamp, errorList, getRuntime, isPrivateIPv4 } from './utils.js';
 Start servitsy with configuration from command line arguments.
 */
 export async function run() {
+	const logger = new Logger(process.stdout, process.stderr);
 	const args = new CLIArgs(argv.slice(2));
 
 	if (args.has('--version')) {
@@ -43,7 +44,7 @@ export async function run() {
 		return;
 	}
 
-	const cliServer = new CLIServer(options);
+	const cliServer = new CLIServer(options, logger);
 	cliServer.start();
 }
 
@@ -53,8 +54,10 @@ export class CLIServer {
 	#portIterator: IterableIterator<number>;
 	#localNetworkInfo?: NetworkInterfaceInfo;
 	#server: Server;
+	#logger: Logger;
 
-	constructor(options: Required<ServerOptions>) {
+	constructor(options: Required<ServerOptions>, logger: Logger) {
+		this.#logger = logger;
 		this.#options = options;
 		this.#portIterator = new Set(options.ports).values();
 		this.#localNetworkInfo = Object.values(networkInterfaces())
@@ -65,14 +68,16 @@ export class CLIServer {
 		const server = createServer(async (req, res) => {
 			const handler = new RequestHandler({ req, res, resolver, options });
 			res.on('close', () => {
-				logger.write('request', requestLogLine(handler.data()));
+				this.#logger.write('request', requestLogLine(handler.data()));
 			});
 			await handler.process();
 		});
 		server.on('error', (error) => this.onError(error));
 		server.on('listening', () => {
 			const info = this.headerInfo();
-			if (info) logger.write('header', info, { top: 1, bottom: 1 });
+			if (info) {
+				this.#logger.write('header', info, { top: 1, bottom: 1 });
+			}
 		});
 
 		this.#server = server;
@@ -138,7 +143,7 @@ export class CLIServer {
 				this.shutdown();
 			} else if (!helpShown) {
 				helpShown = true;
-				logger.write('info', 'Hit Control+C or Escape to stop the server.');
+				this.#logger.write('info', 'Hit Control+C or Escape to stop the server.');
 			}
 		});
 		stdin.setRawMode(true);
@@ -159,7 +164,7 @@ export class CLIServer {
 		this.#shuttingDown = true;
 
 		process.exitCode = 0;
-		const promise = logger.write('info', 'Gracefully shutting down...');
+		const promise = this.#logger.write('info', 'Gracefully shutting down...');
 		this.#server.closeAllConnections();
 		this.#server.close();
 		await promise;
@@ -178,7 +183,7 @@ export class CLIServer {
 				} else {
 					const { ports } = this.#options;
 					const msg = `${ports.length > 1 ? 'ports' : 'port'} already in use: ${ports.join(', ')}`;
-					logger.error(msg);
+					this.#logger.error(msg);
 					exit(1);
 				}
 			});
@@ -187,9 +192,9 @@ export class CLIServer {
 
 		// Handle other errors
 		if (error.code === 'ENOTFOUND') {
-			logger.error(`host not found: '${error.hostname}'`);
+			this.#logger.error(`host not found: '${error.hostname}'`);
 		} else {
-			logger.error(error);
+			this.#logger.error(error);
 		}
 		exit(1);
 	}

src/logger.ts

@@ -1,6 +1,6 @@
 import { release } from 'node:os';
 import { platform } from 'node:process';
-import { stderr, stdout } from 'node:process';
+import { type Writable } from 'node:stream';
 import { inspect } from 'node:util';
 
 import type { ResMetaData } from './types.d.ts';
@@ -43,9 +43,14 @@ export class ColorUtils {
 	};
 }
 
-class Logger {
-	#lastout?: LogItem;
-	#lasterr?: LogItem;
+export class Logger {
+	#out: { stream: Writable; last?: LogItem };
+	#err: { stream: Writable; last?: LogItem };
+
+	constructor(out: Writable, err?: Writable) {
+		this.#out = { stream: out };
+		this.#err = { stream: err ?? out };
+	}
 
 	async write(
 		group: LogItem['group'],
@@ -62,18 +67,14 @@ class Logger {
 		}
 
 		const { promise, resolve, reject } = withResolvers<void>();
-		const writeCallback = (err: Error | undefined) => {
+
+		const dest = group === 'error' ? this.#err : this.#out;
+		const text = this.#withPadding(dest.last, item);
+		dest.last = item;
+		dest.stream.write(text, (err) => {
 			if (err) reject(err);
 			else resolve();
-		};
-
-		if (group === 'error') {
-			stderr.write(this.#withPadding(this.#lasterr, item), writeCallback);
-			this.#lasterr = item;
-		} else {
-			stdout.write(this.#withPadding(this.#lastout, item), writeCallback);
-			this.#lastout = item;
-		}
+		});
 
 		return promise;
 	}
@@ -202,4 +203,3 @@ function supportsColor(): boolean {
 }
 
 export const color = new ColorUtils(supportsColor());
-export const logger = new Logger();

test/logger.test.ts

@@ -1,7 +1,9 @@
+import { type Buffer } from 'node:buffer';
+import { Writable } from 'node:stream';
 import { stripVTControlCharacters } from 'node:util';
 import { expect, suite, test } from 'vitest';
 
-import { ColorUtils, requestLogLine } from '#src/logger.js';
+import { ColorUtils, Logger, requestLogLine } from '#src/logger.js';
 import type { ResMetaData } from '#types';
 
 suite('ColorUtils', () => {
@@ -43,6 +45,92 @@ suite('ColorUtils', () => {
 	});
 });
 
+suite('Logger', () => {
+	class TestWritable extends Writable {
+		rawContents = '';
+		contents = '';
+		_write(chunk: string | Buffer, encoding: string, cb?: (error?: Error | null) => void) {
+			const str = chunk.toString();
+			this.rawContents += str;
+			this.contents += stripVTControlCharacters(str);
+			if (typeof cb === 'function') cb();
+		}
+	}
+
+	const getLogger = () => {
+		const out = new TestWritable();
+		const err = new TestWritable();
+		const logger = new Logger(out, err);
+		return { out, err, logger };
+	};
+
+	test('Writes logs to their respective out and err streams', async () => {
+		const { out, err, logger } = getLogger();
+		await logger.write('info', 'Info 1');
+		await logger.write('error', 'Error 1');
+		await logger.write('info', 'Info 2');
+		await logger.write('error', 'Error 2');
+		expect(out.contents).toBe(`Info 1\nInfo 2\n`);
+		expect(err.contents).toBe(`Error 1\nError 2\n`);
+	});
+
+	test('Adds blank lines between logs of different groups', async () => {
+		const { out, logger } = getLogger();
+		await logger.write('header', 'Header');
+		await logger.write('request', 'Request 1');
+		await logger.write('request', 'Request 2');
+		await logger.write('info', 'Info 1');
+		await logger.write('request', 'Request 3');
+		await logger.write('request', 'Request 4');
+		await logger.write('request', 'Request 5');
+		await logger.write('info', 'Info 2');
+		expect(out.contents).toBe(`Header
+
+Request 1
+Request 2
+
+Info 1
+
+Request 3
+Request 4
+Request 5
+
+Info 2
+`);
+	});
+
+	test('accepts custom padding', async () => {
+		const { out, logger } = getLogger();
+		await logger.write('info', ['aaa', 'bbb', 'ccc'], {
+			// should yield two `\n`
+			top: 2,
+			// should yield three '\n' (return + two empty lines)
+			bottom: 2,
+		});
+		await logger.write('info', 'final', {
+			// merged with previous log's bottom padding
+			top: 2,
+			// capped at 4, resulting in 5 '\n'
+			bottom: 12,
+		});
+		expect(out.contents).toBe('\n\naaa\nbbb\nccc\n\n\nfinal\n\n\n\n\n');
+	});
+
+	test('error logs strings', async () => {
+		const { err, logger } = getLogger();
+		await logger.error('Error 1');
+		await logger.error('Error 2');
+		expect(err.contents).toBe(`servitsy: Error 1\nservitsy: Error 2\n`);
+	});
+
+	test('error logs Errors with stack trace', async () => {
+		const { err, logger } = getLogger();
+		await logger.error(new Error('Whoops'));
+		expect(err.contents).toMatch(`Error: Whoops`);
+		expect(err.contents).toMatch(/[\\\/]test[\\\/]logger\.test\.ts:\d+:\d+/);
+	});
+});
+
 suite('responseLogLine', () => {
 	const matchLogLine = (data: Omit<ResMetaData, 'url' | 'timing'>, expected: string) => {
 		const rawLine = requestLogLine({