Jest: How to test for object keys and properties?

In version 23.3.0 of jest,

expect(string).toMatch(string) 

expects a string.

Use:

const expected = { name:'component name' }
const actual = { name: 'component name', type: 'form' }
expect(actual).toMatchObject(expected)

result is passing test

you can use one of those:

toEqual and toMatchObject are template matchers for objects:

let Obj = {name: 'component name', id: 2};
expect(oneObj).toEqual({name: 'component name'}) // false, should be exactly equal all Obj keys and values  
expect(oneObj).toMatchObject({name: 'component name'}) // true

or easly use toHaveProperty :

let Obj = {name: 'component name'};
expect(oneObj).toHaveProperty('name') // true
expect(oneObj).toHaveProperty('name', 'component name') // true

Keep in mind that .toMatchObject checks "that a JavaScript object matches a subset of the properties of an object." So it can have unintended assertions as such:

expect({ a: 1, b: 2 }).toMatchObject({ a: 1 }); // pass

If you do want to match an object exactly, you should use .toStrictEqual, available since jest 23:

expect({ a: 1, b: 2 }).toStrictEqual({ a: 1 }); // fail