chore: Mock yup error shape in tests in lieu of full dependency.

It shouldn't be necessary to bring this entire `yup` dependency just to test
compatibility with the shape of a `yup` (https://npm.im/yup) error.

Ref: #1288

package.json

@@ -96,7 +96,6 @@
  "@types/test-listen": "1.1.0",
  "@types/type-is": "1.6.2",
  "@types/ws": "6.0.1",
- "@types/yup": "0.26.22",
  "apollo-fetch": "0.7.0",
  "apollo-link": "1.2.12",
  "apollo-link-http": "1.5.15",
@@ -139,8 +138,7 @@
  "ts-jest": "24.0.2",
  "tslint": "5.18.0",
  "typescript": "3.5.3",
- "ws": "6.2.1",
- "yup": "0.27.0"
+ "ws": "6.2.1"
  },
  "jest": {
  "projects": [

packages/apollo-server-integration-testsuite/src/ApolloServer.ts

@@ -609,15 +609,49 @@ export function testApolloServer<AS extends ApolloServerBase>(
  });
 
  it('works with errors similar to GraphQL errors, such as yup', async () => {
+ // https://npm.im/yup is a package that produces a particular type of
+ // error that we test compatibility with. This test was first brought
+ // with https://github.com/apollographql/apollo-server/pull/1288. We
+ // used to use the actual `yup` package to generate the error, but we
+ // don't need to actually bundle that dependency just to test
+ // compatibility with that particular error shape. To be honest, it's
+ // not clear from the original PR which attribute of this error need be
+ // mocked, but for the sake not not breaking anything, all of yup's
+ // error properties have been reproduced here.
  const throwError = jest.fn(async () => {
- const schema = yup.object().shape({
- email: yup
- .string()
- .email()
- .required('Please enter your email address'),
+ // Intentionally `any` because this is a custom Error class with
+ // various custom properties (like `value` and `params`).
+ const yuppieError: any = new Error('email must be a valid email');
+ yuppieError.name = 'ValidationError';
+
+ // Set `message` to enumerable, which `yup` does and `Error` doesn't.
+ Object.defineProperty(yuppieError, 'message', {
+ enumerable: true,
  });
 
- await schema.validate({ email: 'lol' });
+ // Set other properties which `yup` sets.
+ yuppieError.path = 'email';
+ yuppieError.type = undefined;
+ yuppieError.value = { email: 'invalid-email' };
+ yuppieError.errors = ['email must be a valid email'];
+ yuppieError.inner = [];
+ yuppieError.params = {
+ path: 'email',
+ value: 'invalid-email',
+ originalValue: 'invalid-email',
+ label: undefined,
+ regex: /@/,
+ };
+
+ // This stack is fake, but roughly what `yup` generates!
+ yuppieError.stack = [
+ 'ValidationError: email must be a valid email',
+ ' at createError (yup/lib/util/createValidation.js:64:35)',
+ ' at yup/lib/util/createValidation.js:113:108',
+ ' at process._tickCallback (internal/process/next_tick.js:68:7)',
+ ].join('\n');
+
+ throw yuppieError;
  });
 
  const formatError = jest.fn(error => {