Naming Convention

GraphQL Code Generation provides a namingConvention option to control the naming convention of the different code elements generated (types, enum values, …).

`namingConvention`

type: NamingConvention default: change-case-all#pascalCase

Allow you to override the naming convention of the output.

You can either override all namings or specify an object with a specific custom naming convention per output. The converter format must be a valid module#method.

Allowed values for specific output are: typeNames, enumValues. You can also use "keep" to keep all GraphQL names as-is. Additionally, you can set transformUnderscore to true if you want to override the default behavior to preserve underscores.

Usage Examples

Override All Names

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: { namingConvention: 'change-case-all#lowerCase' }
  // ...
}
export default config

Upper-case enum values

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: {
    namingConvention: {
      typeNames: 'change-case-all#pascalCase',
      enumValues: 'change-case-all#upperCase'
    }
  }
  // ...
}
export default config

Keep names as is

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: { namingConvention: 'keep' }
  // ...
}
export default config

Remove Underscores

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: {
    namingConvention: {
      typeNames: 'change-case-all#pascalCase',
      transformUnderscore: true
    }
  }
  // ...
}
export default config

Using external modules

All the examples you saw so far were using change-case-all package.

The change-case-all package being a direct dependency of graphql-codegen, you can use it directly.

However, you can use any other package as long as it is installed as a dependency. The same syntax needs to be used:

package-name#export-you-want-to-use

For example, if you want to use camelCase from lodash, given that you have it already installed, you will do it like this:

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: { namingConvention: 'lodash#camelCase' }
  // ...
}
export default config

Providing your own naming function

As you may have guessed already, there is nothing fancy about naming functions. They are just functions that take a string as input and produce it as output.

If you stick to that signature, you can provide your own naming function. You need to provide a CJS module with a default export of a function that takes a string and returns a string.

The following example provides a workaround to a limitation of change-case-all:

my-naming-fn.js

// Fix for https://github.com/dotansimha/graphql-code-generator/issues/6040
const { constantCase } = require('change-case-all')
/**
 * This function wraps constant case, that turns any string into CONSTANT_CASE
 * However, this function has a bug that, if you pass _ to it it will return an empty
 * string. This small module fixes that
 *
 * @param {string*} str
 * @return {string}
 */
function FixedConstantCase(str) {
  const result = constantCase(str)
  // If result is an empty string, just return the original string
  return result || str
}
module.exports = FixedConstantCase

Then, just provide the path to your custom naming module in the configuration:

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: { namingConvention: './my-naming-fn' }
  // ...
}
export default config

This also applies when you want a specific custom naming convention per output. Specify your custom naming function on the output or outputs you want to apply:

import { CodegenConfig } from '@graphql-codegen/cli'
 
const config: CodegenConfig = {
  // ...
  config: {
    namingConvention: {
      typeNames: './my-naming-fn'
    }
  }
  // ...
}
export default config

Last updated on August 31, 2022

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