Naming an argument 'query' results in exception when parsing the GraphQL query

[walmartlabs]

Naming an argument 'query' results in exception when parsing the GraphQL query

[hlship]

In our grammar, query is a reserved word. I'll check the spec to see if there's anything similar. If not, we'll have to figure out how to convince the parser to accept the value there.

By "not working" do you mean that you get an exception or a parse error, or what?

[hlship]

clojure.lang.ExceptionInfo: Failed to parse GraphQL query.
                            clojure.core/eval    core.clj: 3105
                                          ...                  
                                user/eval6250   REPL Input     
   com.walmartlabs.lacinia.parser/parse-query  parser.clj: 1221
   com.walmartlabs.lacinia.parser/parse-query  parser.clj: 1227
com.walmartlabs.lacinia.parser/parse-query/fn  parser.clj: 1231
                         clojure.core/ex-info    core.clj: 4617
clojure.lang.ExceptionInfo: Failed to parse GraphQL query.
    errors: ({:location {:line 1, :column nil},
              :parse-error "mismatched input 'query' expecting Name"}
             {:location {:line 1, :column nil},
              :parse-error "mismatched input ':' expecting {'(', '{', '@', Name}"}
             {:location {:line 1, :column nil},
              :parse-error
              "extraneous input '}' expecting {<EOF>, 'query', 'mutation', 'subscription', '{', 'fragment'}"})

[stijnopheide]

yes, that's exactly the exception we see.

Also, the workaround is easy, just use another name for the argument. Maybe a mention in the documentation about reserved words can avoid confusion for other users for now?

[hlship]

True, I'd like to test this against the reference implementation to see if it can accept it.

[stijnopheide]

There is another use case in which you will get this exception and this when the query sent by the client will use the word 'query' anywhere in the input objects.

e.g.
query DoQuery($query: String) {someQuery(q: $query) {result}}
and the input to that query
{"query": "lalala"}

This is I think more problematic because it has nothing to do with the schema and from the clients' perspective the error message is very confusing.

[hlship]

Just checked against the RI:

var { graphql, buildSchema } = require('graphql');

var schema = buildSchema(`
  type Query {
    query: String
  }
`);

var root = { query: () => 'Hello world!' };

graphql(schema, '{ query }', root).then((response) => {
  console.log(response);
});

... and this works as expected. So query is only a "reserved word" when it appears in that location. I'll have to do some work to figure out how to make this work correctly in Antlr.

[hlship]

This one is turning out to be a disproportionate amount of work vs. reward.