ignore non-enumerable symbols

Author: Rich-Harris

src/stringify.js

@@ -1,5 +1,6 @@
 import {
 	DevalueError,
+	enumerable_symbols,
 	get_type,
 	is_plain_object,
 	is_primitive,
@@ -143,7 +144,7 @@ export function stringify(value, reducers) {
 						);
 					}
 
-					if (Object.getOwnPropertySymbols(thing).length > 0) {
+					if (enumerable_symbols(thing).length > 0) {
 						throw new DevalueError(
 							`Cannot stringify POJOs with symbolic keys`,
 							keys

src/uneval.js

@@ -1,5 +1,6 @@
 import {
 	DevalueError,
+	enumerable_symbols,
 	escaped,
 	get_type,
 	is_plain_object,
@@ -89,7 +90,7 @@ export function uneval(value, replacer) {
 						);
 					}
 
-					if (Object.getOwnPropertySymbols(thing).length > 0) {
+					if (enumerable_symbols(thing).length > 0) {
 						throw new DevalueError(
 							`Cannot stringify POJOs with symbolic keys`,
 							keys

src/utils.js

@@ -97,3 +97,10 @@ export function stringify_string(str) {
 
 	return `"${last_pos === 0 ? str : result + str.slice(last_pos)}"`;
 }
+
+/** @param {Record<string | symbol, any>} object */
+export function enumerable_symbols(object) {
+	return Object.getOwnPropertySymbols(object).filter(
+		(symbol) => Object.getOwnPropertyDescriptor(object, symbol).enumerable
+	);
+}

test/test.js

@@ -390,6 +390,19 @@ const fixtures = {
 				assert.equal(Object.getPrototypeOf(value), Object.prototype);
 				assert.equal(Object.keys(value).length, 0);
 			}
+		},
+		{
+			name: 'non-enumerable symbolic key',
+			value: (() => {
+				const obj = { x: 1 };
+				Object.defineProperty(obj, Symbol('key'), {
+					value: 'value',
+					enumerable: false
+				});
+				return obj;
+			})(),
+			js: '{x:1}',
+			json: '[{"x":1},1]'
 		}
 	],