functional-javascript-workshop/exercises/basic_every_some/problem.md

The basics of functional programming in JavaScript. No libraries required.

# Task

Return a function that takes a list of valid users, and returns a function that returns true if all of the supplied users exist in the original list of users.

You only need to check that the ids match.

## Example

```js
var goodUsers = [
  { id: 1 },
  { id: 2 },
  { id: 3 }
]

// `checkUsersValid` is the function you'll define
var testAllValid = checkUsersValid(goodUsers)

testAllValid([
  { id: 2 },
  { id: 1 }
])
// => true

testAllValid([
  { id: 2 },
  { id: 4 },
  { id: 1 }
])
// => false
```

## Arguments

* goodUsers: a list of valid users

Use array#some and Array#every to check every user passed to your returned function exists in the array passed to the exported function.

## Conditions

* Do not use any for/while loops or Array#forEach.
* Do not create any unnecessary functions e.g. helpers.

## Resources

* https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/every
* https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/some

## Boilerplate

```js
function checkUsersValid(goodUsers) {
  return function allUsersValid(submittedUsers) {
    // SOLUTION GOES HERE
  };
}

module.exports = checkUsersValid
```