From c8c8ce0bcfdc1a016c080fefa0f8c6b629c98896 Mon Sep 17 00:00:00 2001
From: Volker Schukai <volker.schukai@schukai.com>
Date: Mon, 25 Nov 2024 13:00:06 +0100
Subject: [PATCH] fix: optimize instanceof operator
---
source/types/is.mjs | 10 ++++++-
test/cases/types/is.mjs | 60 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/source/types/is.mjs b/source/types/is.mjs
index 1fc67ae6e..de9754d7c 100644
--- a/source/types/is.mjs
+++ b/source/types/is.mjs
@@ -173,7 +173,15 @@ function isInstance(value, instance) {
if (!isObject(value)) return false;
if (!isFunction(instance)) return false;
if (!instance.hasOwnProperty("prototype")) return false;
- return value instanceof instance ? true : false;
+ if(value instanceof instance) return true;
+
+ let proto = Object.getPrototypeOf(value);
+ while (proto != null) {
+ if (proto === instance.prototype) return true;
+ proto = Object.getPrototypeOf(proto);
+ }
+
+ return false;
}
/**
diff --git a/test/cases/types/is.mjs b/test/cases/types/is.mjs
index 8be3a39ae..852ee3109 100644
--- a/test/cases/types/is.mjs
+++ b/test/cases/types/is.mjs
@@ -238,7 +238,65 @@ describe('Is', function () {
});
});
});
-
+
+ describe('.isInstanceExtended()', function () {
+ class Base {}
+ class Derived extends Base {}
+ function AnotherClass() {}
+
+ let baseInstance = new Base();
+ let derivedInstance = new Derived();
+
+ // Test cases
+ const cases = [
+ [() => {}, undefined, false,"function vs undefined"],
+ [new ID(), ()=>{}, false, "ID instance vs function"],
+ [new ID(), ID, true, "ID instance vs ID"],
+ ['test1', undefined, false, "string vs undefined"],
+ [undefined, undefined, false, "undefined vs undefined"],
+ [null, undefined, false, "null vs undefined"],
+ [2, undefined, false, "number vs undefined"],
+ [false, undefined, false, "false vs undefined"],
+ [parseInt("a"), undefined, false, "NaN vs undefined"],
+ [true, undefined, false, "true vs undefined"],
+ [4.5, undefined, false, "float vs undefined"],
+ [{}, undefined, false, "object vs undefined"],
+ [[1, 2, 3], undefined, false, "array vs undefined"],
+ [Symbol("foo"), undefined, false, "symbol vs undefined"],
+ [baseInstance, Base, true, "Base instance vs Base"],
+ [derivedInstance, Base, true, "Derived instance vs Base"],
+ [derivedInstance, Derived, true, "Derived instance vs Derived"],
+ [baseInstance, Derived, false, "Base instance vs Derived"],
+ [baseInstance, AnotherClass, false, "Base instance vs AnotherClass"],
+ [derivedInstance, ()=>{}, false, "Derived instance vs function"],
+ [new AnotherClass(), AnotherClass, true, "AnotherClass instance vs AnotherClass"],
+ ];
+
+ // Adding prototype modification test
+ let protoModifiedInstance = new Base();
+ Object.setPrototypeOf(protoModifiedInstance, Derived.prototype);
+ cases.push(
+ [protoModifiedInstance, Base, true, "Proto modified Base instance vs Base"],
+ [protoModifiedInstance, Derived, true, "Proto modified Base instance vs Derived"]
+ );
+
+ // Running the tests
+ cases.forEach(function (data) {
+ const a = data.shift();
+ const b = data.shift();
+ const c = data.shift();
+ const d = data.shift();
+
+ it('isInstance(' + JSON.stringify(a) + ', [Function]) should return ' + c, function () {
+
+ if (isInstance(a, b)!==c) {
+ console.log(d)
+ }
+
+ expect(isInstance(a, b)).to.equal(c);
+ });
+ });
+ });
describe('.isObject()', function () {
--
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