@cran/lib.gql.core/mjs/plugins/withMetadata.js

GQL Core Functionality

import { isOutputType, } from "graphql";
import { Plugin } from "./Plugin";
import { IntrospectionType, createDirective, getExtension, patchField, setExtension, } from "../utilities";
export function withMetadata(options) {
    const plugins = [];
    for (const key in options.fields) {
        if ("default" !== key) {
            const kind = key;
            plugins.push(createDirective(options.names?.[kind] ?? `${IntrospectionType[kind].name.slice(2)}Metadata`, { ...options.fields.default, ...options.fields[kind], }, { [kind]: directiveMapper, }));
        }
    }
    plugins.push({
        transformer: {
            [Plugin.Phase.FINALIZE](schema) {
                for (const name in options.fields) {
                    if ("default" !== name) {
                        addFields(schema, name, options);
                    }
                }
                return schema;
            },
        },
    });
    return plugins;
}
function directiveMapper([directive,], type) {
    setExtension(type, "metadata", directive);
}
function addFields(schema, kind, options) {
    const field = options.fields[kind];
    for (const key in field) {
        const type = schema.getType(field[key]);
        if (!type || !isOutputType(type)) {
            throw new TypeError(`MetadataPlugin expects "GraphQLOutputType" received "${type?.name}"`);
        }
        addField(kind, key, type, options);
    }
}
function addField(kind, key, type, options) {
    const fallback = options.fallbacks?.[kind] || alwaysNull;
    patchField(IntrospectionType[kind], key, {
        type,
        resolve(source) {
            const value = getExtension(source, "metadata")?.[key];
            return value ?? fallback(source, key);
        },
    });
}
function alwaysNull() { return null; }