MockedProvider does not validate GraphQL queries

[richardwu]

Intended outcome:

I am testing my React Native app which includes Apollo queries with Jest, and I noticed that the MockedProvider does not validate the GraphQL query, such as for undefined references. Here is a reproduce-able test file using react-testing-library and MockedProvider:

import React from "react";

import { render } from "@testing-library/react-native";
import "@testing-library/jest-dom";

import { MockedProvider } from "@apollo/client/testing";
import { View, Text } from "react-native";

import { gql, useQuery } from "@apollo/client";

const BAD_QUERY = gql`
  query bob($foo1: String!, $foo2: String!) {
    bob(foo1: $undefined_foo1, foo2: $undefined_foo2) {
      bar
    }
  }
`;

const mocks = [
  {
    request: {
      query: BAD_QUERY,
      variables: {
        foo1: "abc",
        foo2: "abc",
      },
    },
    result: {
      data: {
        bob: { bar: 1 },
      },
    },
  },
];

const TestComp = () => {
  const { data } = useQuery(BAD_QUERY, {
    variables: { foo1: "abc", foo2: "abc" },
  });

  return (
    <View>
      <Text>{data?.bob.bar}</Text>
    </View>
  );
};

describe("TestComp", () => {
  test("test comp", async () => {
    const { findByText } = render(
      <MockedProvider mocks={mocks} addTypename={false}>
        <TestComp />
      </MockedProvider>
    );

    expect(await findByText("1")).toBeTruthy();
  });
});

Actual outcome:
Even though the above BAD_QUERY includes undefined references $undefined_foo1, $undefined_foo2, the test still passes. However, if rendering TestComp with a non-mocked Apollo client the correct undefined GraphQL error is thrown:

[GraphQL error]: Message: Variable "$undefined_foo1" is not defined by operation "bob".

How to reproduce the issue:

See the above code block.

Versions

  System:
    OS: Linux 4.19 Ubuntu 20.04.1 LTS (Focal Fossa)
  Binaries:
    Node: 15.0.1 - ~/.nvm/versions/node/v15.0.1/bin/node
    Yarn: 1.22.5 - /usr/bin/yarn
    npm: 7.0.3 - ~/.nvm/versions/node/v15.0.1/bin/npm
  Browsers:
    Firefox: 84.0
  npmPackages:
    @apollo/client: ^3.2.5 => 3.2.5

Using SDK 40.