ConfigModel: Returns error if option of config not set

Overview

These tests validate nestjs-mod ConfigModel: configuration transformation, input validation, and error contract on invalid parameters.

What We Do And Verify

• We verify how configTransform and ConfigModel/ConfigModelProperty decorators process input parameters.

• We lock the validation contract and error shape expected by configuration consumers.

• We confirm that modules/services receive properly prepared configuration values.

• We explicitly validate the error contract: not only failure itself, but also error shape/content expected by module consumers.

GitHub Reference

• File: utils.spec.ts
• Line: 10

Setup Code

import { DynamicModule } from '@nestjs/common';
import { Injectable, Module } from '@nestjs/common';
import { TestingModule } from '@nestjs/testing';
import { Test } from '@nestjs/testing';
import { IsNotEmpty } from 'class-validator';
import { ConfigModel, ConfigModelProperty } from './decorators';
import { configTransform } from './utils';

describe('Config model: Utils', () => {
  // full test in the block below

});

Test Code

  it('should return error if option of config not set', async () => {
    @ConfigModel()
    class AppConfig {
      @ConfigModelProperty()
      @IsNotEmpty()
      option!: string;
    }

    @Module({ providers: [AppConfig] })
    class AppModule {
      static forRoot(config: Partial<AppConfig>): DynamicModule {
        return {
          module: AppModule,
          providers: [
            {
              provide: `${AppConfig.name}_loader`,
              useFactory: async (emptyAppConfig: AppConfig) => {
                if (config.constructor !== Object) {
                  Object.setPrototypeOf(emptyAppConfig, config);
                }
                const obj = await configTransform({
                  model: AppConfig,
                  data: config,
                });
                Object.assign(emptyAppConfig, obj.data);
              },
              inject: [AppConfig],
            },
          ],
        };
      }
    }

    await expect(
      Test.createTestingModule({
        imports: [AppModule.forRoot({})],
      }).compile(),
    ).rejects.toHaveProperty('errors.0.constraints.isNotEmpty', 'option should not be empty');
  });