@toptal/davinci-graphql-codegen-extensions/src/enums-plugin.js

Toptal Graphql codegen extensions

const {
  getCachedDocumentNodeFromSchema,
} = require('@graphql-codegen/plugin-helpers')
const { visit } = require('graphql')

const annotationDirective = 'tt_earlySupport'

module.exports = {
  plugin(schema) {
    const astNode = getCachedDocumentNodeFromSchema(schema)

    const enums = []

    visit(astNode, {
      EnumTypeDefinition(node) {
        const enumName = node.name.value
        const ignoredValues = node.values.filter(value =>
          value.directives
            .map(directive => directive.name.value)
            .includes(annotationDirective)
        )

        if (ignoredValues.length > 0) {
          enums.push({
            name: enumName,
            values: ignoredValues.map(value => value.name.value),
          })
        }
      },
    })

    let output = ''

    if (enums.length > 0) {
      output +=
        'type WithOptional<Type, OptionalKeys extends keyof Type> = Omit<Type, OptionalKeys> & Partial<Pick<Type, OptionalKeys>>\n \n'

      const mapping = enums
        .map(({ name, values }) => {
          const keys = values.map(value => `${name}.${value}`)

          return `[${name}] extends [EnumType] ? WithOptional<Record<${name}, ValueType>, ${keys.join(
            '|'
          )}> \n`
        })
        .join(':')

      output += `export type GraphqlEnumMapping<EnumType extends keyof any, ValueType> = \n  ${mapping}  : Record<EnumType, ValueType>\n`
    } else {
      output += `export type GraphqlEnumMapping<EnumType extends keyof any, ValueType> = Record<EnumType, ValueType>\n`
    }

    return output
  },
}