@apollo/react-testing will always raise an error when using newData

[zombiezen]

tl;dr: I believe these lines are wrong:

react-apollo/packages/testing/src/mocks/mockLink.ts

Lines 90 to 101 in 3c05b08

	const { result, error, delay, newData } = response;
	if (newData) {
	response.result = newData();
	this.mockedResponsesByKey[key].push(response);
	}
	if (!result && !error) {
	throw new Error(
	`Mocked response should contain either result or error: ${key}`
	);
	}

IIUC the assignment on line 90 should be moved to after the if (newData) conditional.

Intended outcome:

Use the newData function in a MockLink response.

Actual outcome:

Error thrown: Mocked response should contain either result or error

How to reproduce the issue:

Try to mock a response with:

const fakeData = [
  {
    request: {query: QUERY},
    newData: () => ({data: { /* ... */ }})
  }
];
const link = new MockLink(fakeData);

Version

  System:
    OS: Linux 4.4 Debian GNU/Linux 9 (stretch) 9 (stretch)
  Binaries:
    Node: 8.15.0 - /usr/bin/node
    Yarn: 1.16.0 - ~/bin/yarn
    npm: 6.4.1 - /usr/bin/npm
  npmPackages:
    apollo-boost: ^0.4.4 => 0.4.4

[pawelkleczek10c]

I have the same issue

[hwillson]

Fixed in #3539 (new version coming soon). Thanks @zombiezen @pawelkleczek10c!