@pfeiferio/object-utils

Small, predictable utility functions for working with plain JavaScript objects.

This package provides a minimal set of helpers for object inspection and deep merging with strict, explicit behavior and zero dependencies.

Installation

npm install @pfeiferio/object-utils

Usage

import {
  isObject,
  isPlainObject,
  mergeObjects
} from '@pfeiferio/object-utils'

isObject(value)

Checks whether a value is a non-null object, excluding arrays.

isObject({})        // true
isObject([])        // false
isObject(null)      // false
isObject('string')  // false

This is a safe alternative to typeof value === 'object'.

isPlainObject(value)

Checks whether a value is a plain object.

A plain object is defined as:

• created via object literal ({})
• or Object.create(null)

isPlainObject({})                  // true
isPlainObject(Object.create(null)) // true

isPlainObject([])                  // false
isPlainObject(new Date())          // false
isPlainObject(null)                // false

Useful for merge logic and configuration handling.

mergeObjects(a, b)

Deeply merges two values.

• Only plain objects are merged recursively
• All other values overwrite
• Inputs are never mutated

mergeObjects(
  { server: { host: 'example.com' } },
  { server: { port: 80 } }
)
// → { server: { host: 'example.com', port: 80 } }

Overwrite behavior

mergeObjects(
  { a: { b: 1 } },
  { a: 2 }
)
// → { a: 2 }

mergeObjects(
  { list: [1, 2] },
  { list: [3] }
)
// → { list: [3] }

Non-plain values always win

mergeObjects(
  { a: { b: 1 } },
  null
)
// → null

Design Principles

• Explicit semantics
• No array merging
• No mutation
• Predictable results
• Suitable for configuration and business logic

This package intentionally avoids:

• implicit deep cloning
• class instance merging
• array merging heuristics

License

MIT