fix(sync): avoid symlink loops

src/async.js

@@ -1,20 +1,25 @@
 import { join, resolve } from 'path';
-import { readdir, stat } from 'fs';
+import { lstat, readdir, realpath } from 'fs';
 import { promisify } from 'util';
 
-const toStats = promisify(stat);
-const toRead = promisify(readdir);
+const real = promisify(realpath);
+const toStats = promisify(lstat);
+const list = promisify(readdir);
 
-export async function totalist(dir, callback, pre='') {
-	dir = resolve('.', dir);
-	await toRead(dir).then(arr => {
+export async function totalist(dir, callback, prefix, cache) {
+	cache = cache || new Set;
+	dir = await real(resolve('.', dir));
+	if (cache.has(dir)) return;
+
+	cache.add(dir);
+	await list(dir).then(arr => {
 		return Promise.all(
 			arr.map(str => {
 				let abs = join(dir, str);
 				return toStats(abs).then(stats => {
 					return stats.isDirectory()
-						? totalist(abs, callback, join(pre, str))
-						: callback(join(pre, str), abs, stats)
+						? totalist(abs, callback, join(prefix || '', str), cache)
+						: callback(join(prefix || '', str), abs, stats)
 				});
 			})
 		);

src/sync.d.ts

@@ -1,3 +1,3 @@
 import { Stats } from 'fs';
 export type Caller = (relPath: string, absPath: string, stats: Stats) => any;
-export function totalist(dir: string, callback: Caller, prefix?: string): void;
+export function totalist(dir: string, callback: Caller, prefix?: string, cache?: Set<string>): void;

src/sync.js

@@ -1,15 +1,18 @@
 import { join, resolve } from 'path';
-import { readdirSync, statSync } from 'fs';
+import { lstatSync, readdirSync, realpathSync } from 'fs';
 
-export function totalist(dir, callback, pre='') {
-	dir = resolve('.', dir);
-	let arr = readdirSync(dir);
-	let i=0, abs, stats;
-	for (; i < arr.length; i++) {
-		abs = join(dir, arr[i]);
-		stats = statSync(abs);
-		stats.isDirectory()
-			? totalist(abs, callback, join(pre, arr[i]))
-			: callback(join(pre, arr[i]), abs, stats);
+export function totalist(dir, callback, prefix, cache) {
+	cache = cache || new Set;
+	dir = realpathSync(resolve('.', dir));
+	if (!cache.has(dir)) {
+		cache.add(dir);
+		let i=0, abs, stats;
+		let arr = readdirSync(dir);
+		for (; i < arr.length; i++) {
+			stats = lstatSync(abs = join(dir, arr[i]));
+			stats.isDirectory()
+				? totalist(abs, callback, join(prefix || '', arr[i]), cache)
+				: callback(join(prefix || '', arr[i]), abs, stats);
+		}
 	}
 }

test/async.js

@@ -1,3 +1,4 @@
+import * as fs from 'fs';
 import { test } from 'uvu';
 import * as assert from 'uvu/assert';
 import { join, normalize } from 'path';
@@ -52,4 +53,32 @@ test('(async) usage :: absolute', async () => {
 });
 
 
+test('usage :: symbolic directory', async () => {
+	let symlink = join(fixtures, 'symlink');
+	fs.symlinkSync(fixtures, symlink);
+
+	try {
+		let count = 0;
+		let items = {};
+
+		await totalist(fixtures, (name, abs, stats) => {
+			count++;
+			assert.not(stats.isDirectory(), 'file is not a directory');
+			assert.ok(abs.startsWith(fixtures), '~> `abs` is absolute');
+			assert.not(name.startsWith(fixtures), '~> `name` is NOT absolute');
+			assert.is(stats.isSymbolicLink(), abs === symlink);
+
+			items[abs] = (items[abs] || 0) + 1;
+		});
+
+		const keys = Object.keys(items);
+		assert.is(count, 7, 'saw 7 files total');
+		assert.is(keys.length, 7, '~> unique file paths');
+		assert.ok(keys.every(k => items[k] === 1), '~> saw each item once');
+	} finally {
+		fs.unlinkSync(symlink);
+	}
+});
+
+
 test.run();

test/sync.js

@@ -1,3 +1,4 @@
+import * as fs from 'fs';
 import { test } from 'uvu';
 import * as assert from 'uvu/assert';
 import { join, normalize } from 'path';
@@ -51,4 +52,32 @@ test('usage :: absolute', () => {
 });
 
 
+test('usage :: symbolic directory', () => {
+	let symlink = join(fixtures, 'symlink');
+	fs.symlinkSync(fixtures, symlink);
+
+	try {
+		let count = 0;
+		let items = {};
+
+		totalist(fixtures, (name, abs, stats) => {
+			count++;
+			assert.not(stats.isDirectory(), 'file is not a directory');
+			assert.ok(abs.startsWith(fixtures), '~> `abs` is absolute');
+			assert.not(name.startsWith(fixtures), '~> `name` is NOT absolute');
+			assert.is(stats.isSymbolicLink(), abs === symlink);
+
+			items[abs] = (items[abs] || 0) + 1;
+		});
+
+		const keys = Object.keys(items);
+		assert.is(count, 7, 'saw 7 files total');
+		assert.is(keys.length, 7, '~> unique file paths');
+		assert.ok(keys.every(k => items[k] === 1), '~> saw each item once');
+	} finally {
+		fs.unlinkSync(symlink);
+	}
+});
+
+
 test.run();