apollo-link-fake

Convenient Apollo mocking

Installation

npm

npm install --save-dev apollo-link-fake

yarn

yarn add --dev apollo-link-fake

Usage

This example is recommended usage which uses FakeQL and a configured GraphQL project. For more advanced usage take a look at the full API reference

With the following schema is configured:

type Query {
  user: User!
}

type User {
  name: String!
  age: Int!
}

And this component under test:

const link = new MockLink();
const Component = (): JSX.Element => {
  const { loading, data } = useQuery(query);

  if (!data || loading) {
    return <>Loading…</>;
  }

  return (
    <div>
      Hello my name is <span>{data.user.name}</span> and I am{" "}
      <span>{data.user.age} years old</span>
    </div>
  );
};

This is an example of a test using apollo-link-fake:

const { getByText } = render(
  <MockedProvider addTypename={false} link={link}>
    <Component />
  </MockedProvider>
);

expect(getByText("Loading…")).toBeInTheDocument();

link.resolveMostRecentOperation((operation) =>
  fakeQL({ operation })
);

expect(getByText(`mock-value-for-field-"name"`)).toBeInTheDocument();
expect(getByText("42 years old")).toBeInTheDocument();

API reference

Types

• Result - is defined as Record<string, unknown> which translates to any {}.

Methods

• pendingOperations - Get all operations executed so far that have not been resolved or rejected.
• mostRecentOperation - Return the most recent operation. Throws an error when there are no pending operations.
• resolveMostRecentOperation - Given a Result or a function Operation => Result, resolves the operation with the provided Result. Throws an error when there are no pending operations.
• • rejectMostRecentOperation - Given a Error or a function Operation => Error, rejects the operation with the provided Error. Throws an error when there are no pending operations.
• findOperation - Given a predicate (Operation) -> boolean returns the first operation for which the predicate is true. Throws an error if no matching operation is found.

PendingOperation

Some methods return a PendingOperation which has the following API:

• resolve - Resolves the operation with the provided Result
• reject - Rejects the operation with the provided Error