isObject

The isObject type guard checks if a value is a non-null object.

Basic Usage

import { isObject } from "cx/util";

isObject({}); // true
isObject([]); // true (arrays are objects)
isObject(new Date()); // true
isObject(null); // false
isObject(undefined); // false
isObject("string"); // false
isObject(42); // false
isObject(true); // false

How It Works

The function checks two conditions:

1. The value is not null
2. The typeof is "object"

export function isObject(o: unknown): o is object {
  return o !== null && typeof o === "object";
}

Type Narrowing

The function is a TypeScript type guard that narrows the type to object.

import { isObject } from "cx/util";

function processValue(value: unknown): void {
  if (isObject(value)) {
    // value is typed as 'object' here
    console.log(Object.keys(value));
  }
}

Common Use Cases

Safe Property Access

import { isObject } from "cx/util";

function getProperty(obj: unknown, key: string): unknown {
  if (isObject(obj) && key in obj) {
    return (obj as Record<string, unknown>)[key];
  }
  return undefined;
}

Data Validation

import { isObject } from "cx/util";

function validateConfig(config: unknown): config is Record<string, unknown> {
  return isObject(config) && !Array.isArray(config);
}

Deep Clone Check

import { isObject, isArray } from "cx/util";

function deepClone<T>(value: T): T {
  if (!isObject(value)) return value;
  if (isArray(value)) return value.map(deepClone) as T;

  const result: Record<string, unknown> = {};
  for (const key in value) {
    result[key] = deepClone((value as Record<string, unknown>)[key]);
  }
  return result as T;
}

API

function isObject(o: unknown): o is object;

Returns: true if the value is a non-null object (including arrays).