Simple, readable, structural type comparisons.
import assert from 'assert'
import { diff, Nullable, Optional, Any } from 'type-diff'
const Type = {
id: Number,
tags: [String]
contacts: [{
id: Number,
name: String,
contacted: Nullable(Date),
tags: Optional([String]),
wharrgarbl: Any()
}]
}
const value = {
id: 1,
tags: ['good', 'cool'],
contacts: [
{ id: 2, name: 'John Doe', contacted: null, wharrgarbl: _ => 'wheee' },
{ id: '3', name: 'Jane Doe', contacted: new Date(), tags: ['cool'] }
]
}
assert.deepEqual(diff(Type, value), {
contacts: {
'1': {
id: {
actual: 'String',
expected: 'Number',
value: '3'
},
wharrgarbl: {
actual: 'Undefined',
expected: 'Any'
}
}
}
})diff(Type, value)
Generate an object literal representation of the difference between your Type and a given value as shown above in the Quick Example.
NumberStringBooleanObjectArrayDateFunction
Nullable(Type): Allows the corresponding value to be either the correct Type or null.
Optional(Type): Allows the corresponding value to be either the correct Type or undefined.
Any | Any(): Requires that the corresponding value be anything but undefined. Used in conjuction with Optional if undefined is allowed; as in Optional(Any)