Naming Convention#

Codegen support many forms on outputs, and you can control the general naming-convention of the types/variables/code generated, using the namingConvention config flag.

`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 specific custom naming convention per output. The format of the converter 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, which is to preserve underscores.

Usage Examples#

Override All Names#

config:
  namingConvention: change-case-all#lowerCase

Upper-case enum values#

config:
  namingConvention:
    typeNames: change-case-all#pascalCase
    enumValues: change-case-all#upperCase

Keep names as is#

config:
  namingConvention: keep

Remove Underscores#

config:
  namingConvention:
    typeNames: change-case-all#pascalCase
    transformUnderscore: true

Using external modules#

All the examples you saw so far were using change-case-all package. That package is a dependency of graphql-codegen, so you can use it directly. However, you can use any other package as long as you have it installed as dependency. You need to use the same syntax as you saw previously but with the package of your choice. The syntax is as:

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:

config:
  namingConvention: lodash#camelCase

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 an string 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 an string and returns an string. On the following example there is a workaround for a limitation that change-case-all functions has.

// 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, on the config you just provide the path to your custom naming module:

config:
  namingConvention: ./my-naming-fn

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

config:
  namingConvention:
    typeNames: ./my-naming-fn

Naming Convention#