Add repeatable directives

[dugenkui03]

#1763

1. Add repeatable directives;

2. change the UniqueDirectiveNamesPerLocation to ignore repeatable directive;

3. change the Introspection to follow the spec:

type __Directive {
  name: String!
  description: String
  locations: [__DirectiveLocation!]!
  args: [__InputValue!]!
  isRepeatable: Boolean!
}

[bbakerman]

nice catch

[bbakerman]

please use fully formed if statements

if (graphQLDirective == null) {
    continue;
}

more lines : yes - more readable : also yes

[andimarek]

by using the GraphQL java code formatter it will be automatically handled.

[bbakerman]

I think we will want to transfer the AST isRepeatable into the runtime GraphQLDirective class.

That is inside SchemaGenerator related code we transfer these booleans over

The AST elements are for reading SDL - the GraphqlXXX class are aimed as the runtime equivalents with more logic in them and more state rules.

[dugenkui03]

thanks for your guidance

[bbakerman]

This is start to the repeatable directives. However it only handles "queries" and not the type system

Its valid to do this

   type Foo {
     secureField : String @securedGroup(name : "admins")  @securedGroup(name : "execs")
   }

So we would need repeatable directives to go into the GraphqlXXX types as well.

The challenge here is that while they expose <List> getDirectives they have a map on the builder

private final Map<String, GraphQLDirective> directives = new LinkedHashMap<>();

These would need to be fixed up - thank good we made it a list and not a map to the outside world

phew

[bbakerman]

Thanks for this work. In order to collaborate on this (where we can add code and so could you) I am going to close this PR and use a long lived branch

See #1916

branch : support_repeatable_directives

Please make any future PRs against that branch and we can collaboratively get this up

[bbakerman]

Again this code so far is pretty good and a great start - its just that it need to be the full support to make it into the master and we may work on improving that as well outselves

[dugenkui03]

Again this code so far is pretty good and a great start - its just that it need to be the full support to make it into the master and we may work on improving that as well outselves

thanks