Passing context to @cypher, scalar payload mutations, fixes

[michaeldgraham]

This PR introduces fixes and improvements to @cypher directive fields.

Passing context data to @cypher statements

Passing context values to @cypher directive statements is now supported via a dedicated cypherParams context object in an Apollo server setup (#187).

In the below example, currentUserId is provided in the cypherParams context object. It can then be accessed as a Cypher parameter in all @cypher directives (including custom queries and mutations).

const server = new ApolloServer({
  ...,
  context: ({ req }) => {
    return {
      driver,
      req,
      cypherParams: {
        currentUserId: req.user.id
      }
    };
  }
});

const typeDefs = `
  type User {
    name: String
    currentUserId: String @cypher(statement: """
      RETURN $cypherParams.currentUserId
    """)
  }
`;

Fixes

• Scalar payload types on @cypher fields (TypeError: Cannot read property 'selections' of undefined #145)

• Input type arguments on @cypher fields (Input type parameter not passed to custom Cypher query #192)

• Parameterized arguments on nested @cypher fields (Improper variable handling in cypher directive #136)

• Contains additional fix for removal of neo4j_ignore generation https://community.neo4j.com/t/orderby-with-makeaugmentedschema/4998/2

• Contains fix for parsing issue from augmentation process refactoring (Fields with arguments cause GraphQL Error #190)

Tests

Handle @cypher field with String payload using cypherParams
Handle nested @cypher fields that use cypherParams
Handle @cypher query using cypherParams with String payload
Handle @cypher query using cypherParams with Object payload
Handle @cypher query with Boolean payload
Handle @cypher query with Int payload
Handle @cypher query with Float payload
Handle @cypher query with String list payload
Handle @cypher query with Int list payload
Handle @cypher query with Temporal payload
Handle @cypher mutation using cypherParams with String payload
Handle @cypher mutation using cypherParams with Object payload
Handle @cypher mutation with String list payload
Handle @cypher mutation with Temporal payload
Handle @cypher mutation with input type argument
Handle @cypher query with parameterized input type argument
Handle nested @cypher fields using parameterized arguments and cypherParams