GraphQL.js accepts arrays as input object inputs

README.md

If you pass an array in place of an input object, an error is raised for each individual field that doesn't match, plus each "extra key" the array has (i.e. numeric indicies).

mkdir demo
cd demo
yarn add graphql @graphql-tools/schema
node repro.mjs

Expected result: one error (user is not an object)

Actual result: 6 errors (one for each missing key, and one for each array index)

repro.mjs

// @ts-check
import { makeExecutableSchema } from "@graphql-tools/schema";
import { graphql, validateSchema } from "graphql";

const schema = makeExecutableSchema({
  typeDefs: /* GraphQL */ `
    input UserInput {
      firstName: String!
      lastName: String!
      businessPhone: String!
      email: String!
      jobTitle: String
    }

    type User {
      firstName: String!
      lastName: String!
      businessPhone: String!
      email: String!
      jobTitle: String
    }

    type Mutation {
      updateUser(user: UserInput!): User!
    }

    type Query {
      hello: String
    }
  `,
  resolvers: {
    Query: {
      hello: () => "Hello, world!",
    },
    Mutation: {
      updateUser: (_, { user }) => {
        console.log("Received user input:", user);

        return {
          firstName: user.firstName,
          lastName: user.lastName,
          businessPhone: user.businessPhone,
          email: user.email,
          jobTitle: user.jobTitle || null,
        };
      },
    },
  },
});

const errors = validateSchema(schema);
if (errors.length > 0) {
  console.dir(errors);
  throw new Error("Invalid schema");
}

const result = await graphql({
  schema,
  source: /* GraphQL */ `
    mutation UpdateUser($user: UserInput!) {
      updateUser(user: $user) {
        firstName
        lastName
      }
    }
  `,
  variableValues: {
    user: [{ firstName: "Alice" }, { firstName: "Bob" }],
  },
});

console.dir(result);