fix(utils): compare Date values by time in deepEqualObj

.changeset/deep-equal-date-compare.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/utils": patch
+---
+
+fix(utils): compare Date values by time in deepEqualObj

packages/core/utils/src/common/__tests__/deep-equal-obj.spec.ts

@@ -30,4 +30,17 @@ describe("deepEqualObj", function () {
 
     expect(deepEqualObj(object1, object2)).toBe(false)
   })
+
+  it("should compare Date values by time, not by their (empty) keys", function () {
+    expect(deepEqualObj(new Date(0), new Date(0))).toBe(true)
+    expect(deepEqualObj(new Date(0), new Date(999999))).toBe(false)
+    expect(
+      deepEqualObj({ created_at: new Date(0) }, { created_at: new Date(0) })
+    ).toBe(true)
+    expect(
+      deepEqualObj({ created_at: new Date(0) }, { created_at: new Date(999999) })
+    ).toBe(false)
+    // a Date is not equal to a plain object
+    expect(deepEqualObj(new Date(0), {})).toBe(false)
+  })
 })

packages/core/utils/src/common/deep-equal-obj.ts

@@ -11,6 +11,16 @@ export function deepEqualObj(obj1: unknown, obj2: unknown): boolean {
     return obj2 === obj1
   }
 
+  // Dates expose no own enumerable keys, so the key comparison below would treat
+  // any two Date instances as equal; compare their time value instead.
+  if (obj1 instanceof Date || obj2 instanceof Date) {
+    return (
+      obj1 instanceof Date &&
+      obj2 instanceof Date &&
+      obj1.getTime() === obj2.getTime()
+    )
+  }
+
   const obj1Keys = Object.keys(obj1)
   const obj2Keys = Object.keys(obj2)