Merge pull request #1665 from input-output-hk/feat/lw-13507-do-not-serialize-if-already-serialized

feat(util): return identical fromSerializableObject if already serialized [LW-13507]

Author: mirceahasegan

packages/util/src/serializableObject.ts

@@ -44,6 +44,18 @@ const hasInnerError = (error: unknown): error is { innerError: unknown } =>
 const innerErrorHasData = (innerError: unknown): innerError is { data: unknown } =>
   typeof innerError === 'object' && innerError !== null && 'data' in innerError;
 
+const isNativeNonSerializableType = (obj: unknown): boolean => {
+  if (typeof obj === 'undefined' || typeof obj === 'bigint') return true;
+  if (typeof obj === 'object' && obj !== null) {
+    if (obj instanceof Date) return true;
+    if (obj instanceof Error) return true;
+    if (obj instanceof Map) return true;
+    if (obj instanceof Set) return true;
+    if (ArrayBuffer.isView(obj)) return true;
+  }
+  return false;
+};
+
 export const toSerializableObject = (obj: unknown, options: ToSerializableObjectOptions = {}): unknown => {
   if (PLAIN_TYPES.has(typeof obj)) return obj;
   const { transformationTypeKey = defaultTransformationTypeKey, serializeKey = defaultTransformKey } = options;
@@ -110,7 +122,9 @@ export const toSerializableObject = (obj: unknown, options: ToSerializableObject
 };
 
 const fromSerializableObjectUnknown = (obj: unknown, options: FromSerializableObjectOptions = {}): unknown => {
-  if (PLAIN_TYPES.has(typeof obj)) return obj;
+  if (PLAIN_TYPES.has(typeof obj)) return obj; // no-op for plain types
+  if (isNativeNonSerializableType(obj)) return obj; // no-op for native types
+
   if (typeof obj === 'object') {
     if (obj === null) return null;
     if (Array.isArray(obj)) {

packages/util/test/serializableObject.test.ts

@@ -111,5 +111,19 @@ describe('serializableObject', () => {
       const obj = [{ a: [{ b: 1, c: '2' }] }, 3];
       expect(fromSerializableObject(obj)).toEqual(obj);
     });
+
+    it('returns the identical object when input is already serialized', () => {
+      const obj = {
+        bigint: 123n,
+        buffer: new Uint8Array(Buffer.from('data')),
+        date: new Date(),
+        error: new Error('error obj'),
+        map: new Map([['key', 1n]]),
+        nullVal: null,
+        set: new Set(['item1', 1n]),
+        undefinedVal: undefined
+      };
+      expect(fromSerializableObject(obj)).toEqual(obj);
+    });
   });
 });