Object Keys

import objectKeys from "object-keys";

const objectKeys = require("object-keys");

// Use native Object.keys if available, fallback to polyfill
const keys = Object.keys || require("object-keys");

// Install globally and use native Object.keys API
require("object-keys").shim();
// Now Object.keys works everywhere

const objectKeys = require("object-keys");

// Direct usage as Object.keys replacement
const obj = { a: 1, b: 2, c: 3 };
const keys = objectKeys(obj);
console.log(keys); // ['a', 'b', 'c']

// Recommended fallback pattern
const keys = Object.keys || require("object-keys");
const myKeys = keys({ x: 1, y: 2 }); // ['x', 'y']

// Global shimming approach
objectKeys.shim(); // Install Object.keys globally if needed
Object.keys(obj); // Now works reliably in all environments

// Conditional usage based on environment
if (!Object.keys) {
  Object.keys = require("object-keys");
}

/**
 * Get enumerable property names from an object
 * @param {object|function|arguments} obj - The object to get keys from
 * @returns {string[]} Array of enumerable property names
 * @throws {TypeError} When called on primitive values (null, undefined, number, string, boolean)
 */
function objectKeys(obj);

const objectKeys = require("object-keys");

// Basic object
const user = { name: "Alice", age: 30, active: true };
const keys = objectKeys(user);
// Result: ['name', 'age', 'active']

// Array (returns indices)
const arr = ['a', 'b', 'c'];
const indices = objectKeys(arr);
// Result: ['0', '1', '2']

// String object
const str = new String("hello");
const strKeys = objectKeys(str);
// Result: ['0', '1', '2', '3', '4']

// Arguments object
function example() {
  return objectKeys(arguments);
}
const argKeys = example('a', 'b');
// Result: ['0', '1']

// Function objects (with custom properties)
function myFunc() {}
myFunc.customProp = true;
const funcKeys = objectKeys(myFunc);
// Result: ['customProp']

// Object instances (only own enumerable properties)
function Constructor() {
  this.instanceProp = true;
}
Constructor.prototype.prototypeProp = true;
const instance = new Constructor();
const instanceKeys = objectKeys(instance);
// Result: ['instanceProp'] (prototype properties excluded)

/**
 * Install Object.keys shim globally if needed
 * @returns {Function} The shimmed Object.keys function or original if already present
 */
objectKeys.shim();

const objectKeys = require("object-keys");

// Install shim (safe to call multiple times)
const shimmedKeys = objectKeys.shim();

// Now Object.keys is available globally
const obj = { x: 1, y: 2 };
const keys = Object.keys(obj); // Works in all environments

// The shim handles Safari 5.0 arguments bug automatically
function testArguments() {
  return Object.keys(arguments); // Fixed to work correctly
}

// These will throw TypeError:
objectKeys(null);        // TypeError: Object.keys called on a non-object
objectKeys(undefined);   // TypeError: Object.keys called on a non-object
objectKeys(42);          // TypeError: Object.keys called on a non-object
objectKeys("hello");     // TypeError: Object.keys called on a non-object
objectKeys(true);        // TypeError: Object.keys called on a non-object
objectKeys(false);       // TypeError: Object.keys called on a non-object

// These work fine:
objectKeys({});                 // []
objectKeys([]);                 // []
objectKeys(function(){});       // [] or ['prototype'] depending on environment
objectKeys(arguments);          // ['0', '1', ...] based on arguments
objectKeys(new String("test")); // ['0', '1', '2', '3']
objectKeys(Object("hello"));    // ['0', '1', '2', '3', '4']