A generator that walks the prototype chain of an object
npm install isotropic-prototype-chain
A generator function that walks through the prototype chain of an object.
- Simple Iteration: Easily iterate through all prototypes in an object's chain
- Generator-Based: Uses JavaScript generators for efficient lazy iteration
- Reflection API: Built on the modern Reflect API for reliable prototype access
- No Dependencies: Lightweight implementation with zero runtime dependencies
``bash`
npm install isotropic-prototype-chain
`javascript
import _prototypeChain from 'isotropic-prototype-chain';
// Create an object with a prototype chain
class Animal {}
class Mammal extends Animal {}
class Dog extends Mammal {}
const dog = new Dog();
// Iterate through the prototype chain
for (const prototype of prototypeChain(dog)) {
console.log(prototype);
}
// Outputs: Dog instance, Mammal.prototype, Animal.prototype, Object.prototype, null
`
A generator function that yields each prototype in the chain, starting with the object itself and continuing up to Object.prototype.
#### Parameters
- object (Object): The object whose prototype chain to iterate.
#### Returns
- (Generator): A generator that yields each object in the prototype chain, starting with the input object and continuing to the end of the chain.
`javascript
import _prototypeChain from 'isotropic-prototype-chain';
const object = {
a: 1
},
prototypeChain = [
..._prototypeChain(object)
];
console.log(prototypeChain); // [{ a: 1 }, Object.prototype]
`
`javascript
import _prototypeChain from 'isotropic-prototype-chain';
// Create a chain of objects with custom inheritance
const _child = {
name: 'Child',
},
_grandparent = {
name: 'Grandparent'
},
_parent = {
name: 'Parent'
};
Object.setPrototypeOf(_child, _parent);
Object.setPrototypeOf(_parent, _grandparent);
// Print the chain of names
for (const object of _prototypeChain(_child)) {
console.log(object.name);
}
// Outputs: "Child", "Parent", "Grandparent", undefined
`
`javascript
import _prototypeChain from 'isotropic-prototype-chain';
// Get all property names from the entire prototype chain
const _getPropertyNameSet = object => {
const propertyNameSet = new Set();
for (const prototype of _prototypeChain(object)) {
for (const propertyName of Object.getOwnPropertyNames(prototype)) {
propertyNameSet.add(propertyName);
}
}
return propertyNameSet;
}
class A {
constructor () {
this.propA = 'A';
}
methodA () {}
}
class B extends A {
constructor () {
super();
this.propB = 'B';
}
methodB () {}
}
class C extends B {
constructor () {
super();
this.propC = 'C';
}
methodC() {}
}
console.log(...getPropertyNameSet(new C()));
// Outputs: propA propB propC constructor methodC methodB methodA, etc.
`
`javascript
import _prototypeChain from 'isotropic-prototype-chain';
// Check if an object inherits from multiple specific constructors/classes
const _inheritsFrom = (object, ...constructorFunctions) => {
const prototypeSet = new Set();
// Collect all constructor prototypes to check against
constructorFunctions.forEach(constructorFunction => {
prototypeSet.add(constructorFunction.prototype);
});
// Check if any prototype in the chain matches any of the constructor prototypes
let foundCount = 0;
for (const prototype of _prototypeChain(object)) {
if (prototypeSet.has(prototype)) {
foundCount += 1;
}
}
return foundCount === constructorFunctions.length;
}
// Test with inheritance
class Base {}
class Derived extends Base {}
{
const object = new Derived();
console.log(_inheritsFrom(object, Derived, Base)); // true
console.log(_inheritsFrom(object, Base)); // true
console.log(_inheritsFrom(object, Array)); // false
}
``
Please refer to CONTRIBUTING.md for contribution guidelines.
If you encounter any issues, please file them at https://github.com/ibi-group/isotropic-prototype-chain/issues