@toptal/davinci-graphql-codegen-extensions/src/schema-loader.js

Toptal Graphql codegen extensions

const { parse, visit, buildASTSchema } = require('graphql')
const { readFileSync } = require('fs')

const annotationDirective = 'tt_earlySupportHidden'

module.exports = function (schemaString) {
  const schemaContent = readFileSync(schemaString, {
    encoding: 'utf-8',
  }).toString()

  const ast = parse(schemaContent)

  const newAst = visit(ast, {
    leave(node) {
      if (
        node.kind === 'EnumValueDefinition' &&
        node.directives
          .map(directive => directive.name.value)
          .includes(annotationDirective)
      ) {
        return null
      }
      // @return
      //   undefined: no action
      //   false: no action
      //   visitor.BREAK: stop visiting altogether
      //   null: delete this node
      //   any value: replace this node with the returned value
    },
  })

  return buildASTSchema(newAst)
}