Generate all GraphQL mutations from GraphQL schema IDL

generateAllMutations.mjs

import fs from 'fs'

const header = `
#
# This file is auto generated. Do not edit by hand.
#
`.trimStart()

const schema = fs.readFileSync('path/to/schema.graphql', 'utf8')
const allMutations = generateAllMutations(schema).join('\n')

fs.writeFileSync('path/to/mutations.graphql', header + allMutations, 'utf8')

/** @param {string} schema */
function generateAllMutations(schema) {
  schema = schema.replace(/[\s\S]+type Mutation/, '')
  // Regex to extract all mutation fields from the schema
  const mutationsRegex = /(\w+)\(([^)]*)\): (.+)/g
  let match
  const mutations = []

  // Loop through all matches in the schema
  while ((match = mutationsRegex.exec(schema)) !== null) {
    const fieldName = match[1]
    const operationName = fieldName[0].toUpperCase() + fieldName.slice(1)
    const argsString = match[2].trim() // Argument list as string

    // Split the arguments string and create a key-value pair for each argument
    const args = argsString.split(',').reduce((acc, arg) => {
      const [argName, argType] = arg.split(':').map((s) => s.trim())
      acc[argName] = argType
      return acc
    }, {})

    // Generate the GraphQL variable definitions
    const variables = Object.entries(args)
      .map(([arg, type]) => `$${arg}: ${type}`)
      .join(', ')

    // Generate the mutation input arguments
    const mutationInput = Object.keys(args)
      .map((arg) => `${arg}: $${arg}`)
      .join(', ')

    // Create the mutation string with hardcoded return field 'id'
    const mutation = `
    mutation ${operationName}(${variables}) {
      ${fieldName}(${mutationInput}) {
        id
      }
    }`

    mutations.push(mutation)
  }

  return mutations
}

mutations.graphql

# Example output

#
# This file is auto generated. Do not edit by hand.
#

    mutation CreateStore($storeName: String!) {
      createStore(storeName: $storeName) {
        id
      }
    }

    mutation CreateStaff($storeId: ID!, $input: StaffInput!) {
      createStaff(storeId: $storeId, input: $input) {
        id
      }
    }
    
    # ...