Federation Enum not parsing value 0, works other values

[ShadyKutz]

Enums fail to resolve correctly with a value of 0, when using Federation.

Versions:

    "@apollo/federation": "^0.9.4",
    "apollo-server": "^2.9.3",
    "graphql": "^14.1.1",
    "graphql-tools": "^4.0.4"

Example Repo:

https://github.com/postman-nz/gql-federation-issue

Server Code:

const { ApolloServer, gql } = require("apollo-server");
const { buildFederatedSchema } = require("@apollo/federation");

const typeDefs = gql`
  type Query {
    colorBad: AllowedColor
    colorGood: AllowedColor
  }

  enum AllowedColor {
    RED
    GREEN
    BLUE
  }
`;

const resolvers = {
  Query: {
    colorBad: () => 0,
    colorGood: () => 1
  },
  AllowedColor: {
    RED: 0,
    GREEN: 1,
    BLUE: 2
  }
};

// Works with this server
/*
const server = new ApolloServer({
  typeDefs,
  resolvers
});
*/
const server = new ApolloServer({
  schema: buildFederatedSchema({
    typeDefs,
    resolvers
  })
});

server.listen().then(({ url }) => {
  console.log(`🚀  Server ready at ${url}`);
});

Success when running the Query

query {
  colorGood
}

We get the expected result.

{
  "data": {
    "colorGood": "GREEN"
  }
}

Failure when running the query

query {
  colorBad
}

An error is returned: "Expected a value of type \"AllowedColor\" but received: 0"

Expected Behavior:

{
  "data": {
    "colorBad": "RED"
  }
}

If Federation is removed, both of the queries run as expected.