{feature} support toJSON function

bgotink · Sep 9, 2022 · aae8043 · aae8043
1 parent f0de4c1
commit aae8043
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Showing 3 changed files with 21 additions and 1 deletion.
diff --git a/src/json.d.ts b/src/json.d.ts
@@ -308,4 +308,4 @@ export function parse(text: string, reviver: JiKReviver<unknown>): unknown;
  * @param value The JSON value to encode
  * @throws If the given JSON value contains cycles.
  */
-export function stringify(value: JsonValue): string;
+export function stringify(value: unknown): string;
diff --git a/src/json.js b/src/json.js
@@ -234,6 +234,14 @@ function fromJsonValue(
 	},
 	parents,
 ) {
+	if (
+		value != null &&
+		typeof value === 'object' &&
+		typeof (/** @type {{toJSON: Function}} */ (value).toJSON) === 'function'
+	) {
+		value = /** @type {{toJSON: Function}} */ (value).toJSON();
+	}
+
 	if (isLiteral(value)) {
 		const node = Node.create(nodeName);
 		node.addArgument(value ?? null);

diff --git a/test/jik.js b/test/jik.js
@@ -230,4 +230,16 @@ test('parse reviver', () => {
 	]);
 });
 
+test('stringify supports toJSON methods', () => {
+	expect(stringify(new Date('2022-09-09T10:23:23.445Z'))).toBe(
+		'- "2022-09-09T10:23:23.445Z"\n',
+	);
+
+	expect(
+		stringify({
+			toJSON: () => ['an', 'array'],
+		}),
+	).toBe('- "an" "array"\n');
+});
+
 test.run();