Fix output of symbols to make them legal JS (#81)

GHolk · web-flow · commit 180283648add · 2025-09-08T04:22:21.000+07:00
diff --git a/index.js b/index.js
@@ -55,12 +55,26 @@ export default function stringifyObject(input, options, pad) {
 			|| typeof input === 'number'
 			|| typeof input === 'boolean'
 			|| typeof input === 'function'
-			|| typeof input === 'symbol'
 			|| isRegexp(input)
 		) {
 			return String(input);
 		}
 
+		if (typeof input === 'symbol') {
+			const t = input.description;
+			if (t === undefined) return 'Symbol()';
+			if (t.slice(0,7) === 'Symbol.'
+				&& Symbol[t.slice(7)] === input
+			) {
+				return t;
+			}
+			const q = stringify(t, options);
+			if (Symbol.keyFor(input) !== undefined) {
+				return `Symbol.for(${q})`;
+			}
+			return `Symbol(${q})`;
+		}
+
 		if (input instanceof Date) {
 			return `new Date('${input.toISOString()}')`;
 		}
@@ -106,7 +120,9 @@ export default function stringifyObject(input, options, pad) {
 				const eol = objectKeys.length - 1 === index ? tokens.newline : ',' + tokens.newlineOrSpace;
 				const isSymbol = typeof element === 'symbol';
 				const isClassic = !isSymbol && /^[a-z$_][$\w]*$/i.test(element);
-				const key = isSymbol || isClassic ? element : stringify(element, options);
+				let key = element;
+				if (!isClassic) key = stringify(element, options);
+				if (isSymbol) key = '[' + key + ']';
 
 				let value = stringify(input[element], options, pad + indent);
 				if (options.transform) {
diff --git a/test/fixtures/object.js b/test/fixtures/object.js
@@ -24,7 +24,7 @@
   Infinity: Infinity,
   newlines: "foo\nbar\r\nbaz",
   circular: "[Circular]",
-  Symbol(): Symbol(),
-  Symbol(foo): Symbol(foo),
-  Symbol(foo): Symbol(foo)
+  [Symbol()]: Symbol(),
+  [Symbol("foo")]: Symbol("foo"),
+  [Symbol.for("foo")]: Symbol.for("foo")
 }
diff --git a/test/index.js b/test/index.js
@@ -199,5 +199,14 @@ test('don\'t stringify non-enumerable symbols', t => {
 	const symbol = Symbol('for non-enumerable key');
 	Object.defineProperty(object, symbol, {enumerable: false});
 
-	t.is(stringifyObject(object), '{\n\tSymbol(for enumerable key): undefined\n}');
+	t.is(stringifyObject(object), '{\n\t[Symbol(\'for enumerable key\')]: undefined\n}');
+});
+test('handle symbols', t => {
+	const object = {
+		[Symbol('unique')]: Symbol('unique'),
+		[Symbol.for('registry')]: [Symbol.for('registry'), 2],
+		[Symbol.iterator]: {k: Symbol.iterator},
+		[Symbol()]: 'undef'
+	};
+	t.is(stringifyObject(object), '{\n\t[Symbol(\'unique\')]: Symbol(\'unique\'),\n\t[Symbol.for(\'registry\')]: [\n\t\tSymbol.for(\'registry\'),\n\t\t2\n\t],\n\t[Symbol.iterator]: {\n\t\tk: Symbol.iterator\n\t},\n\t[Symbol()]: \'undef\'\n}');
 });
