Fix plain object detection in edge-runtime

Author: marcioapm

package-lock.json

@@ -10,9 +10,12 @@ import {
 	stringToUint8Array,
 } from "../utils";
 
+class SomeClass {}
+
 describe("isObject()", () => {
 	it("should return true with objects", (done) => {
 		expect(isObject({})).toBe(true);
+		expect(isObject(new Object())).toBe(true);
 
 		done();
 	});
@@ -25,6 +28,8 @@ describe("isObject()", () => {
 		expect(isObject(false)).toBe(false);
 		expect(isObject("str")).toBe(false);
 		expect(isObject(new Uint8Array(1))).toBe(false);
+		expect(isObject(new Map())).toBe(false);
+		expect(isObject(new SomeClass())).toBe(false);
 
 		done();
 	});
@@ -45,6 +50,8 @@ describe("isNumeric()", () => {
 		expect(isNumeric(false)).toBe(false);
 		expect(isNumeric([])).toBe(false);
 		expect(isNumeric({})).toBe(false);
+		expect(isNumeric(new Object())).toBe(false);
+		expect(isNumeric(new Map())).toBe(false);
 
 		done();
 	});

src/__tests__/utils.test.js

@@ -27,7 +27,12 @@ export function isNumeric(value: unknown): value is number {
 }
 
 export function isObject(value: unknown): value is Record<string, unknown> {
-	return value instanceof Object && value.constructor === Object;
+	if (!(value instanceof Object)) {
+		return false;
+	}
+
+	const proto = Object.getPrototypeOf(value);
+	return proto == null || proto === Object.prototype;
 }
 
 export function isPromise(value: unknown): value is Promise<unknown> {