43 lines
1.3 KiB
JavaScript
43 lines
1.3 KiB
JavaScript
import { InMemoryCache, ApolloClient, ApolloLink, gql } from '@apollo/client/core';
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const FOO_QUERY = gql`
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query {
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foo
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}
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`;
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/**
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* This function returns a promise that resolves to the final operation after
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* running an ApolloClient query with the given ApolloLink
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*
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* @typedef {Object} TestApolloLinkOptions
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* @property {Object} context the default context object sent along the ApolloLink chain
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*
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* @param {ApolloLink} subjectLink the ApolloLink which is under test
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* @param {TestApolloLinkOptions} options contains options to send a long with the query
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*
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* @returns Promise resolving to the resulting operation after running the subjectLink
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*/
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export const testApolloLink = (subjectLink, options = {}, query = FOO_QUERY) =>
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new Promise((resolve) => {
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const { context = {} } = options;
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// Use the terminating link to capture the final operation and resolve with this.
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const terminatingLink = new ApolloLink((operation) => {
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resolve(operation);
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return null;
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});
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const client = new ApolloClient({
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link: ApolloLink.from([subjectLink, terminatingLink]),
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// cache is a required option
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cache: new InMemoryCache(),
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});
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// Trigger a query so the ApolloLink chain will be executed.
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client.query({
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context,
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query,
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});
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});
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