@tsed/schema/src/decorators/generics/genericOf.ts

JsonSchema module for Ts.ED Framework

import {isObject, Type} from "@tsed/core";

import {JsonEntityStore} from "../../domain/JsonEntityStore.js";
import {string} from "../../fn/string.js";
import {GenericValue} from "../../utils/generics.js";

/**
 * @ignore
 */
function isEnum(type: any) {
  return isObject(type) && !("toJSON" in type);
}

export interface GenericOfChainedDecorators {
  (...args: any): any;

  /**
   * Declare a nested generic models
   * @param generics
   */
  Nested(...generics: GenericValue[]): this;
}

/**
 * Set the types of a Generic class.
 *
 * ## Example
 *
 * ```typescript
 * class Product {
 *   @Property()
 *   label: string;
 * }
 *
 * @Generics("T")
 * class Paginated<T> {
 *   @CollectionOf("T")
 *   data: T[];
 *
 *   @Property()
 *   totalCount: number;
 * }
 *
 * class Payload {
 *    @GenericOf(Product)
 *    products: Paginated<Product>;
 * }
 * ```
 *
 * ## Example with nested generics
 *
 * ```typescript
 * class Product {
 *   @Property()
 *   label: string;
 * }
 *
 * @Generics("T")
 * class Paginated<T> {
 *   @CollectionOf("T")
 *   data: T[];
 *
 *   @Property()
 *   totalCount: number;
 * }
 *
 * @Generics("D")
 * class Submission<D> {
 *   @Property()
 *   _id: string;
 *
 *   @Property("D")
 *   data: D;
 * }
 *
 * class Payload {
 *    @GenericOf(Submissions).Nested(Product)
 *    submissions: Paginated<Submission<Product>>;
 * }
 * ```
 *
 * @param {Type<any>[]} generics
 * @decorator
 * @validation
 * @swagger
 * @schema
 * @input
 * @generics
 */
export function GenericOf(...generics: GenericValue[]): GenericOfChainedDecorators {
  const nestedGenerics: GenericValue[][] = [
    generics.map((type) => {
      if (isEnum(type)) {
        return string().enum(Object.values(type));
      }
      return type;
    })
  ];

  const decorator = (...args: any) => {
    const store = JsonEntityStore.from(...args);
    store.nestedGenerics = nestedGenerics;
  };

  decorator.Nested = (...generics: any) => {
    nestedGenerics.push(generics);

    return decorator;
  };

  return decorator;
}