fix(form-core): use equals() for value-type equality (Temporal, Decimal.js)

Author: mixelburg

packages/form-core/src/utils.ts

@@ -498,6 +498,13 @@ export function evaluate<T>(objA: T, objB: T) {
     return objA.getTime() === objB.getTime()
   }
 
+  if (
+    typeof (objA as any).equals === 'function' &&
+    objA.constructor === objB.constructor
+  ) {
+    return (objA as any).equals(objB)
+  }
+
   if (objA instanceof Map && objB instanceof Map) {
     if (objA.size !== objB.size) return false
     for (const [k, v] of objA) {

packages/form-core/tests/utils.spec.ts

@@ -747,6 +747,18 @@ describe('evaluate', () => {
     expect(dateObjectFalse).toEqual(false)
   })
 
+  it('should test equality for objects with an equals() method (e.g. Temporal, Decimal.js)', () => {
+    class ValueType {
+      constructor(private val: number) {}
+      equals(other: ValueType) {
+        return this.val === other.val
+      }
+    }
+
+    expect(evaluate(new ValueType(1), new ValueType(1))).toEqual(true)
+    expect(evaluate(new ValueType(1), new ValueType(2))).toEqual(false)
+  })
+
   it('should test equality between Map objects', () => {
     const map1 = new Map([
       ['a', 1],