@commitspark/graphql-api/src/graphql/schema-validator.ts

GraphQL API to store and manage structured data with Git

import { GraphQLSchema, GraphQLUnionType, Kind } from 'graphql'

function checkUnionMembersConsistentUseOfEntryDirective(
  schema: GraphQLSchema,
): string {
  const typeMap = schema.getTypeMap()

  for (const [key, type] of Object.entries(typeMap)) {
    if (type.astNode?.kind !== Kind.UNION_TYPE_DEFINITION) {
      continue
    }
    const innerTypes = (type as GraphQLUnionType).getTypes()

    const numberUnionMembersWithEntryDirective = innerTypes.filter(
      (innerType) =>
        !!innerType.astNode &&
        innerType.astNode.directives?.find(
          (directive) => directive.name.value === 'Entry',
        ) !== undefined,
    ).length

    if (
      numberUnionMembersWithEntryDirective !== 0 &&
      numberUnionMembersWithEntryDirective !== innerTypes.length
    ) {
      return `Either all union members of "${type.name}" must have "@Entry" directive or none.`
    }
  }

  return ''
}

export function getValidationResult(schema: GraphQLSchema): string[] {
  const results = []
  results.push(checkUnionMembersConsistentUseOfEntryDirective(schema))
  return results.filter((result) => result !== '')
}