@theguild/federation-composition/esm/supergraph/validation/rules/extension-with-base.js

Open Source Composition library for Apollo Federation

import { GraphQLError } from 'graphql';
export function ExtensionWithBaseRule(context) {
    return {
        ObjectType(objectTypeState) {
            if (objectTypeState.name === 'Query' ||
                objectTypeState.name === 'Mutation' ||
                objectTypeState.name === 'Subscription') {
                return;
            }
            if (!objectTypeState.hasDefinition) {
                if (objectTypeState.byGraph.size > 1 &&
                    Array.from(objectTypeState.byGraph).every(([graphId, meta]) => context.subgraphStates.get(graphId).version === 'v1.0'
                        ? meta.extensionType === '@extends'
                        : false)) {
                    return;
                }
                objectTypeState.byGraph.forEach((_, graph) => {
                    context.reportError(new GraphQLError(`[${context.graphIdToName(graph)}] Type "${objectTypeState.name}" is an extension type, but there is no type definition for "${objectTypeState.name}" in any subgraph.`, {
                        extensions: {
                            code: 'EXTENSION_WITH_NO_BASE',
                        },
                    }));
                });
            }
        },
    };
}