@graphql-tools/schema
Version: 
A set of utils for faster development of GraphQL tools
44 lines (43 loc) • 2.15 kB
JavaScript
import { getNamedType, isScalarType } from 'graphql';
import { forEachField } from '@graphql-tools/utils';
export function assertResolversPresent(schema, resolverValidationOptions = {}) {
    const { requireResolversForArgs, requireResolversForNonScalar, requireResolversForAllFields } = resolverValidationOptions;
    if (requireResolversForAllFields && (requireResolversForArgs || requireResolversForNonScalar)) {
        throw new TypeError('requireResolversForAllFields takes precedence over the more specific assertions. ' +
            'Please configure either requireResolversForAllFields or requireResolversForArgs / ' +
            'requireResolversForNonScalar, but not a combination of them.');
    }
    forEachField(schema, (field, typeName, fieldName) => {
        // requires a resolver for *every* field.
        if (requireResolversForAllFields) {
            expectResolver('requireResolversForAllFields', requireResolversForAllFields, field, typeName, fieldName);
        }
        // requires a resolver on every field that has arguments
        if (requireResolversForArgs && field.args.length > 0) {
            expectResolver('requireResolversForArgs', requireResolversForArgs, field, typeName, fieldName);
        }
        // requires a resolver on every field that returns a non-scalar type
        if (requireResolversForNonScalar !== 'ignore' && !isScalarType(getNamedType(field.type))) {
            expectResolver('requireResolversForNonScalar', requireResolversForNonScalar, field, typeName, fieldName);
        }
    });
}
function expectResolver(validator, behavior, field, typeName, fieldName) {
    if (!field.resolve) {
        const message = `Resolver missing for "${typeName}.${fieldName}".
To disable this validator, use:
  resolverValidationOptions: {
    ${validator}: 'ignore'
  }`;
        if (behavior === 'error') {
            throw new Error(message);
        }
        if (behavior === 'warn') {
            console.warn(message);
        }
        return;
    }
    if (typeof field.resolve !== 'function') {
        throw new Error(`Resolver "${typeName}.${fieldName}" must be a function`);
    }
}