Recreated a portion of the expect library

mini-expect.js

function expect(actual) {
  function prettyJSON(objectToSerialize) {
    return JSON.stringify(objectToSerialize, null, '\t')
  }

  return {
    toBe(expected) {
      if (actual === expected) {
        console.log('✅ Pass')
      } else {
        const message = `References don't match\nReceived: \n${prettyJSON(actual)} \n\nExpected: \n${prettyJSON(expected)}`

        console.log('❌ Fail')
        console.assert(false, message)
      }
    },
    toEqual(expected) {
      if (JSON.stringify(actual) === JSON.stringify(expected)) {
        console.log('✅ Pass')
      } else {
        const message = `\nReceived: \n${prettyJSON(actual)} \n\nExpected: \n${prettyJSON(expected)}`

        console.log('❌ Fail')
        console.assert(false, message)
      }
    },
    toThrow(message) {
      try {
        actual()
        console.log('❌ Fail')
        console.assert(false, 'should have thrown an error')
      } catch(e) {
        if (message && message !== e.message) {
          console.log('❌ Fail')
          console.assert(false, `should have thrown an error with the following message, "${message}" but instead received the following error message, "${e.message}"`)
          return
        }

        console.log('✅ Pass')
      }
    }
  }
}