Fixing arguments order when getting value from AST

[ArnoudThibaut]

Hello,
Given the following InputObjectType :

new InputObjectType([
    'name'   => 'order',
    'fields' => [
        'foo'  => ['type' => Type::string()],
        'bar'  => ['type' => Type::string()]
    ],
]);

and something like order: {bar: "ASC", foo: "ASC"} as value, the return of GraphQL\Utils\AST::valueFromAST will be ['foo' => 'ASC', 'bar' = 'ASC'].

However when the order of arguments has importance, like constructing an ORDER SQL clause, this can pose a problem and the return should be ['bar' => 'ASC', 'foo' = 'ASC'].

The aim of this PR is to fix this by using the order given by the user instead of the order defining during the field configuration.

I used directly assertSame() in the test case instead of the helper method runTestCaseWithVars because this method use assertEquals and this doesn't test the order of the keys.

Tell me if I should replace assertEquals by assertSame in the helper method, I was not sure about that.

fix : api-platform/core#2808

[vladar]

This is not a bug. The specification clearly states this:

Input object fields are unordered

Input object fields may be provided in any syntactic order and maintain identical semantic meaning.

These two queries are semantically identical:

Example № 30

{
  nearestThing(location: { lon: 12.43, lat: -53.211 })
}

Example № 31

{
  nearestThing(location: { lat: -53.211, lon: 12.43 })
}

While I understand what you are trying to achieve, relying on fields / arguments order is not spec-compliant. If we merge this it will make client apps fragile because they will rely on the implementation-specific feature.

See also recent discussion about related topic in the graphql-spec repo.

So for your use-case of order clause the correct model would be a single field of List type. Lists do preserve ordering of elements.

P.S. Edited this comment to address input object fields (initially posted about arguments, but spec addresses both input object fields and arguments ordering)