@vantreeseba/graphql-mocks-codegen

A GraphQL Code Generator plugin that emits a SchemaTypeMap — a { TypeName: GeneratedType } map of every object type in your schema — so you can hand it to @vantreeseba/graphql-mocks's buildMocks<TTypes> and get typed mock pools back without a cast.

Install

npm install -D @vantreeseba/graphql-mocks-codegen
# peer deps you already have for codegen
npm install -D @graphql-codegen/cli @graphql-codegen/typescript
# the runtime the type map is used with
npm install @vantreeseba/graphql-mocks

Usage

Point the plugin at the same generated types file your typescript plugin (or the client preset) emits — by default it imports from ./graphql.

// codegen.ts
import type { CodegenConfig } from '@graphql-codegen/cli';

const config: CodegenConfig = {
  schema: './schema.graphql',
  generates: {
    // your existing typed output
    './src/__generated__/graphql.ts': {
      plugins: ['typescript'],
    },
    // the type map, emitted alongside it
    './src/__generated__/schema-type-map.ts': {
      plugins: ['@vantreeseba/graphql-mocks-codegen'],
    },
  },
};

export default config;

Then type your mock pools straight off the generated map:

import { buildMocks } from '@vantreeseba/graphql-mocks';
import type { SchemaTypeMap } from './__generated__/schema-type-map';

const mocks = buildMocks<SchemaTypeMap>(schema);

mocks.User;                          // User[] — typed, no cast
mocks.find('Todo', (t) => t.done);   // Todo | undefined — predicate item typed

Generated output

For a schema with User and Todo object types, the plugin emits:

import type * as Types from './graphql';

export type SchemaTypeMap = {
  Todo: Types.Todo;
  User: Types.User;
};

The map KEY is the raw GraphQL type name (what the mock pools are keyed by at runtime); the VALUE references the generated TS type via codegen's own naming convention, so it stays correct even if you change namingConvention. Root operation types (Query/Mutation/Subscription) and introspection types are excluded; entries are sorted for deterministic output.

Configuration

All options are optional strings:

| Option | Default | Description | |---|---|---| | typeMapName | SchemaTypeMap | Name of the generated type-map type. | | typesImportPath | ./graphql | Module the generated TS types are imported from. | | typesNamespace | Types | Namespace alias the generated types are imported under. |

'./src/__generated__/schema-type-map.ts': {
  plugins: ['@vantreeseba/graphql-mocks-codegen'],
  config: { typeMapName: 'MockTypes', typesImportPath: '../gen/types' },
},