@envelop/execute-subscription-event/cjs/subscribe.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.subscribe = void 0;
const tslib_1 = require("tslib");
const graphql_1 = require("graphql");
const core_1 = require("@envelop/core");
const promise_helpers_1 = require("@whatwg-node/promise-helpers");
const validateSubscriptionArgsPromise = Promise.resolve().then(() => tslib_1.__importStar(require('graphql'))).then(graphqlModule => graphqlModule
    .validateSubscriptionArgs);
function getSourceEventStream(args, validateSubscriptionArgs) {
    if (validateSubscriptionArgs) {
        const validatedArgs = validateSubscriptionArgs(args);
        if (!('schema' in validatedArgs)) {
            return { errors: validatedArgs };
        }
        // Cast away the installed graphql version's own overloads here for backwards compatability
        const createSourceEventStreamWithValidatedArgs = graphql_1.createSourceEventStream;
        return createSourceEventStreamWithValidatedArgs(validatedArgs);
    }
    const legacyCreateSourceEventStream = graphql_1.createSourceEventStream;
    return legacyCreateSourceEventStream(args.schema, args.document, args.rootValue, args.contextValue, args.variableValues ?? undefined, args.operationName, args.subscribeFieldResolver);
}
/**
 * This is a almost identical port from graphql-js subscribe.
 * The only difference is that a custom `execute` function can be injected for customizing the behavior.
 */
const subscribe = (execute) => (0, core_1.makeSubscribe)(args => {
    const { schema, document, contextValue, variableValues, operationName, fieldResolver } = args;
    return (0, promise_helpers_1.handleMaybePromise)(() => validateSubscriptionArgsPromise, (validateSubscriptionArgs) => (0, promise_helpers_1.handleMaybePromise)(() => getSourceEventStream(args, validateSubscriptionArgs), (resultOrStream) => {
        if (!(0, core_1.isAsyncIterable)(resultOrStream)) {
            return resultOrStream;
        }
        // Map every source value to a ExecutionResult value as described above.
        return (0, core_1.mapAsyncIterator)(resultOrStream, 
        // For each payload yielded from a subscription, map it over the normal
        // GraphQL `execute` function, with `payload` as the rootValue.
        // This implements the "MapSourceToResponseEvent" algorithm described in
        // the GraphQL specification. The `execute` function provides the
        // "ExecuteSubscriptionEvent" algorithm, as it is nearly identical to the
        // "ExecuteQuery" algorithm, for which `execute` is also used.
        (payload) => execute({
            schema,
            document,
            rootValue: payload,
            contextValue,
            variableValues,
            operationName,
            fieldResolver,
        }));
    }));
});
exports.subscribe = subscribe;