@graphql-tools/webpack-loader/esm/parser.js

A set of utils for faster development of GraphQL tools

import { Kind, parse, print } from 'graphql';
/**
 * Strip insignificant whitespace
 * Note that this could do a lot more, such as reorder fields etc.
 */
function normalize(str) {
    return str.replace(/[\s,]+/g, ' ').trim();
}
// A map docString -> graphql document
const docCache = {};
// A map fragmentName -> [normalized source]
const fragmentSourceMap = {};
function cacheKeyFromFragment(fragment) {
    return normalize(print(fragment));
}
/**
 * Take a unstripped parsed document (query/mutation or even fragment), and
 * check all fragment definitions, checking for name->source uniqueness.
 * We also want to make sure only unique fragments exist in the document.
 */
function processFragments(ast) {
    const astFragmentMap = {};
    const definitions = [];
    for (let i = 0; i < ast.definitions.length; i++) {
        const fragmentDefinition = ast.definitions[i];
        if (fragmentDefinition.kind === Kind.FRAGMENT_DEFINITION) {
            const fragmentName = fragmentDefinition.name.value;
            const sourceKey = cacheKeyFromFragment(fragmentDefinition);
            // We know something about this fragment
            if (fragmentSourceMap.hasOwnProperty(fragmentName) &&
                !fragmentSourceMap[fragmentName][sourceKey]) {
                fragmentSourceMap[fragmentName][sourceKey] = true;
            }
            else if (!fragmentSourceMap.hasOwnProperty(fragmentName)) {
                fragmentSourceMap[fragmentName] = {};
                fragmentSourceMap[fragmentName][sourceKey] = true;
            }
            if (!astFragmentMap[sourceKey]) {
                astFragmentMap[sourceKey] = true;
                definitions.push(fragmentDefinition);
            }
        }
        else {
            definitions.push(fragmentDefinition);
        }
    }
    ast.definitions = definitions;
    return ast;
}
export function parseDocument(doc) {
    const cacheKey = normalize(doc);
    if (docCache[cacheKey]) {
        return docCache[cacheKey];
    }
    const parsed = parse(doc, {
        noLocation: true,
    });
    if (!parsed || parsed.kind !== 'Document') {
        throw new Error('Not a valid GraphQL document.');
    }
    // check that all "new" fragments inside the documents are consistent with
    // existing fragments of the same name
    docCache[cacheKey] = processFragments(parsed);
    return parsed;
}