@loopback/openapi-v3/src/generate-schema.ts

Decorators that annotate LoopBack artifacts with OpenAPI v3 metadata and utilities that transform LoopBack metadata to OpenAPI v3 specifications

// Copyright IBM Corp. and LoopBack contributors 2018,2020. All Rights Reserved.
// Node module: @loopback/openapi-v3
// This file is licensed under the MIT License.
// License text available at https://opensource.org/licenses/MIT

import {SchemaObject} from './types';

/**
 * Generate the `type` and `format` property in a Schema Object according to a
 * parameter's type.
 * `type` and `format` will be preserved if provided in `schema`
 *
 * @internal
 * @param type - The JavaScript type of a parameter
 * @param schema - The schema object provided in an parameter object
 */
export function resolveSchema(
  fn?: Function,
  schema: SchemaObject = {},
): SchemaObject {
  let resolvedSchema: SchemaObject = {};

  if (typeof fn === 'function') {
    if (fn === String) {
      resolvedSchema = {type: 'string'};
    } else if (fn === Number) {
      resolvedSchema = {type: 'number'};
    } else if (fn === Boolean) {
      resolvedSchema = {type: 'boolean'};
    } else if (fn === Date) {
      resolvedSchema = {type: 'string', format: 'date-time'};
    } else if (fn === Object) {
      resolvedSchema = {type: 'object'};
    } else if (fn === Array) {
      resolvedSchema = {type: 'array'};
    } else {
      resolvedSchema = {$ref: `#/components/schemas/${fn.name}`};
    }
  }

  return Object.assign(schema, resolvedSchema);
}