@pothos/core/src/refs/input-object.ts

Pothos (formerly GiraphQL) is a plugin based schema builder for creating code-first GraphQL schemas in typescript

import {
  type InputFieldMap,
  type InputFieldsFromShape,
  type InputRef,
  inputShapeKey,
  type PothosInputObjectTypeConfig,
  type SchemaTypes,
} from '../types';
import { BaseTypeRef } from './base';
import type { InputFieldRef } from './input-field';

export class InputObjectRef<Types extends SchemaTypes, T>
  extends BaseTypeRef<Types, PothosInputObjectTypeConfig>
  implements InputRef<T>, PothosSchemaTypes.InputObjectRef<Types, T>
{
  override kind = 'InputObject' as const;

  $inferInput!: T;

  [inputShapeKey]!: T;

  private fields = new Set<() => InputFieldMap>();

  private fieldCbs = new Set<(name: string, ref: InputFieldRef<Types>) => void>();

  constructor(name: string) {
    super('InputObject', name);
  }

  addFields(fields: () => InputFieldMap) {
    this.fields.add(fields);
    for (const cb of this.fieldCbs) {
      for (const [name, ref] of Object.entries(fields())) {
        if (ref) {
          cb(name, ref as InputFieldRef<Types>);
        }
      }
    }
  }

  onField(cb: (name: string, ref: InputFieldRef<Types>) => void) {
    this.fieldCbs.add(cb);
    for (const fieldMap of this.fields) {
      for (const [name, ref] of Object.entries(fieldMap())) {
        if (ref) {
          cb(name, ref as InputFieldRef<Types>);
        }
      }
    }
  }
}

export class ImplementableInputObjectRef<
  Types extends SchemaTypes,
  T extends object,
  Resolved = T,
> extends InputObjectRef<Types, Resolved> {
  builder: PothosSchemaTypes.SchemaBuilder<Types>;

  constructor(builder: PothosSchemaTypes.SchemaBuilder<Types>, name: string) {
    super(name);
    this.builder = builder;
  }

  implement(
    options: PothosSchemaTypes.InputObjectTypeOptions<
      Types,
      InputFieldsFromShape<Types, T, 'InputObject'>
    >,
  ): InputObjectRef<Types, Resolved> {
    this.builder.inputType<
      ImplementableInputObjectRef<Types, T>,
      InputFieldsFromShape<Types, T, 'InputObject'>
    >(this as never, options);

    return this;
  }
}