chai-exclude

Exclude keys to compare from a deep equal operation with chai expect or assert.

Why?

Sometimes you’ll need to exclude object properties that generate unique values while doing an assertion. This plugin makes it easier to remove those properties from comparison.

Works with both objects and array of objects with or without circular references.

Installation

chai-exclude is an ESM package targeting Chai v5 and above.

npm install chai-exclude --save-dev

If you are using Chai v4, you can use the CommonJS version of the package.

npm install chai-exclude@2.1.1 --save-dev

Usage

import { use } from 'chai'
import chaiExclude from 'chai-exclude'
// If you are using TypeScript, the typings for chai-exclude are included in the package
use(chaiExclude)

Examples

All these examples are for JavaScript. If you are using TypeScript and assert, you’ll need to deal with strict types. Take a look at the type definition.

a) excluding

1. Excluding a top level property from an object

// Object
assert.deepEqualExcluding({ a: 'a', b: 'b' }, { b: 'b' }, 'a')
assert.deepEqualExcluding({ a: 'a', b: 'b' }, { a: 'z', b: 'b' }, 'a')
expect({ a: 'a', b: 'b' }).excluding('a').to.deep.equal({ b: 'b' })
expect({ a: 'a', b: 'b' }).excluding('a').to.deep.equal({ a: 'z', b: 'b' })
// Array
assert.deepEqualExcluding([{ a: 'a', b: 'b' }], [{ b: 'b' }], 'a')
assert.deepEqualExcluding([{ a: 'a', b: 'b' }], [{ a: 'z', b: 'b' }], 'a')
expect([{ a: 'a', b: 'b' }]).excluding('a').to.deep.equal([{ b: 'b' }])
expect([{ a: 'a', b: 'b' }]).excluding('a').to.deep.equal([{ a: 'z', b: 'b' }])

1. Excluding multiple top level properties from an object

const obj = {
  a: 'a',
  b: 'b',
  c: {
    d: 'd',
    e: 'e'
  }
}
// Object
assert.deepEqualExcluding(obj, { b: 'b' }, ['a', 'c'])
assert.deepEqualExcluding(obj, { a: 'z', b: 'b' }, ['a', 'c'])
expect(obj).excluding(['a', 'c']).to.deep.equal({ b: 'b' })
expect(obj).excluding(['a', 'c']).to.deep.equal({ a: 'z', b: 'b' })
const array = [
  {
    a: 'a',
    b: 'b',
    c: {
      d: 'd',
      e: 'e'
    }
  }
]
// Array
assert.deepEqualExcluding(array, [{ b: 'b' }], ['a', 'c'])
assert.deepEqualExcluding(array, [{ a: 'z', b: 'b' }], ['a', 'c'])
expect(array).excluding(['a', 'c']).to.deep.equal([{ b: 'b' }])
expect(array).excluding(['a', 'c']).to.deep.equal([{ a: 'z', b: 'b' }])

b) excludingEvery

1. Excluding every property in a deeply nested object

const actualObj = {
  a: 'a',
  b: 'b',
  c: {
    a: 'a',
    b: {
      a: 'a',
      d: {
        a: 'a',
        b: 'b',
        d: null
      }
    }
  },
  d: ['a', 'c']
}
const actualArray = [actualObj]
const expectedObj = {
  a: 'z',     // a is excluded from comparison
  b: 'b',
  c: {
    b: {
      d: {
        b: 'b',
        d: null
      }
    }
  },
  d: ['a', 'c']
}
const expectedArray = [expectedObj]
// Object
assert.deepEqualExcludingEvery(actualObj, expectedObj, 'a')
expect(actualObj).excludingEvery('a').to.deep.equal(expectedObj)
// Array
assert.deepEqualExcludingEvery(actualArray, expectedArray, 'a')
expect(actualArray).excludingEvery('a').to.deep.equal(expectedArray)

1. Excluding multiple properties in a deeply nested object

const actualObj = {
  a: 'a',
  b: 'b',
  c: {
    a: 'a',
    b: {
      a: 'a',
      d: {
        a: 'a',
        b: 'b',
        d: null
      }
    }
  },
  d: ['a', 'c']
}
const actualArray = [actualObj]
const expectedObj = {
  b: 'b',
  c: {
    b: {
    }
  }
}
const expectedArray = [expectedObj]
// Object
assert.deepEqualExcludingEvery(actualObj, expectedObj, ['a', 'd'])
expect(actualObj).excludingEvery(['a', 'd']).to.deep.equal(expectedObj)
// Array
assert.deepEqualExcludingEvery(actualArray, expectedArray, ['a', 'd'])
expect(actualArray).excludingEvery(['a', 'd']).to.deep.equal(expectedArray)

Contributing

Contributions are welcome. If you have any questions create an issue here.

License

MIT