@benzene/http/dist/index.js

Fast, minimal, agnostic GraphQL over HTTP

import { isExecutionResult, validateOperationName } from '@benzene/core';
export * from '@benzene/core';
import { GraphQLError } from 'graphql';

/**
 * Extract GraphQLParams from query string and body
 * @param request An object contains the body object and query object
 */
function getGraphQLParams({ query, body, }) {
    return {
        query: body?.query || query?.query,
        variables: body?.variables ||
            (query?.variables && JSON.parse(query.variables)),
        operationName: body?.operationName ||
            query?.operationName,
        extensions: body?.extensions ||
            (query?.extensions && JSON.parse(query.extensions)),
    };
}
/**
 * Parse the string body based on content-type according to the graphql-over-http spec
 * @param rawBody
 * @param oCtype
 * @see {@link https://graphql.org/learn/serving-over-http}
 */
function parseGraphQLBody(rawBody, oCtype = "") {
    const semiIndex = oCtype.indexOf(";");
    const ctype = (semiIndex !== -1 ? oCtype.substring(0, semiIndex) : oCtype).trim();
    switch (ctype) {
        case "application/graphql+json":
            try {
                return JSON.parse(rawBody);
            }
            catch (e) {
                throw new Error("POST body sent invalid JSON.");
            }
        case "application/json":
            try {
                return JSON.parse(rawBody);
            }
            catch (e) {
                throw new Error("POST body sent invalid JSON.");
            }
        case "application/graphql":
            return { query: rawBody };
        default:
            // If no Content-Type header matches, parse nothing.
            return null;
    }
}

function createResponse(GQL, code, result) {
    return {
        payload: GQL.formatExecutionResult(result),
        status: code,
        headers: { "content-type": "application/json" },
    };
}
/**
 * Create a handler to handle incoming request
 * @param GQL A Benzene instance
 * @param options Handler options
 */
function makeHandler(GQL, 
// @ts-ignore
options = {}) {
    /**
     * A function that handles incoming request
     * @param socket The incoming request
     * @param extra An extra field to store anything that needs to be accessed later
     */
    return async function graphqlHTTP(request, extra) {
        let params = getGraphQLParams(request);
        if (options.onParams) {
            const onParamsResult = await options.onParams(params);
            if (onParamsResult) {
                if (isExecutionResult(onParamsResult)) {
                    return createResponse(GQL, 200, onParamsResult);
                }
                params = onParamsResult;
            }
        }
        if (!params.query) {
            return createResponse(GQL, 400, {
                errors: [new GraphQLError("Must provide query string.")],
            });
        }
        const cachedOrResult = GQL.compile(params.query, params.operationName);
        if (isExecutionResult(cachedOrResult)) {
            return createResponse(GQL, 400, cachedOrResult);
        }
        if (request.method !== "POST" && request.method !== "GET") {
            return createResponse(GQL, 405, {
                errors: [
                    new GraphQLError("GraphQL only supports GET and POST requests."),
                ],
            });
        }
        const operationNameValidationErrors = validateOperationName(cachedOrResult.operation, params.operationName);
        if (operationNameValidationErrors.length > 0) {
            return createResponse(GQL, 400, {
                errors: operationNameValidationErrors,
            });
        }
        if (request.method === "GET" && cachedOrResult.operation !== "query") {
            return createResponse(GQL, 405, {
                errors: [
                    new GraphQLError(`Can only perform a ${cachedOrResult.operation} operation from a POST request.`),
                ],
            });
        }
        return createResponse(GQL, 200, await GQL.execute({
            document: cachedOrResult.document,
            contextValue: GQL.contextFn
                ? await GQL.contextFn({ extra })
                : undefined,
            variableValues: params.variables,
            operationName: params.operationName,
            compiled: cachedOrResult,
        }));
    };
}

export { makeHandler, parseGraphQLBody };