feat: add providers

Author: Ivanko5417

src/handlers/carts/carts.controller.ts

@@ -7,6 +7,11 @@ import { UpdateCartDto } from './dto/update-cart.dto';
 export class CartsController {
   constructor(private readonly cartsService: CartsService) {}
 
+  @Get('/average')
+  average() {
+    return this.cartsService.average();
+  }
+
   @Post()
   create(@Body() createCartDto: CreateCartDto) {
     return this.cartsService.create(createCartDto);

src/handlers/carts/carts.module.ts

@@ -1,8 +1,10 @@
 import { Module } from '@nestjs/common';
 import { CartsService } from './carts.service';
 import { CartsController } from './carts.controller';
+import { UtilsModule } from '../../services/utils/utils.module';
 
 @Module({
+  imports: [UtilsModule],
   controllers: [CartsController],
   providers: [CartsService]
 })

src/handlers/carts/carts.service.ts

@@ -1,9 +1,20 @@
-import { Injectable } from '@nestjs/common';
+import { Inject, Injectable } from '@nestjs/common';
 import { CreateCartDto } from './dto/create-cart.dto';
 import { UpdateCartDto } from './dto/update-cart.dto';
+import { UtilsService } from '../../services/utils/utils.service';
 
 @Injectable()
 export class CartsService {
+  constructor(
+    private readonly utilsService: UtilsService,
+
+    @Inject('DateService')
+    private readonly DateService,
+  ) {}
+
+  average() {
+    return this.utilsService.average([1,2,3]);
+  }
   create(createCartDto: CreateCartDto) {
     return 'This action adds a new cart';
   }

src/handlers/carts/dto/update-cart.dto.ts

@@ -1,4 +1,3 @@
-import { PartialType } from '@nestjs/mapped-types';
 import { CreateCartDto } from './create-cart.dto';
 
-export class UpdateCartDto extends PartialType(CreateCartDto) {}
+export class UpdateCartDto extends CreateCartDto {}

src/services/utils/utils.constants.ts

@@ -0,0 +1,3 @@
+export const PRECISION = 2;
+export const START_DATE = new Date().getTime();
+

src/services/utils/utils.module.ts

@@ -0,0 +1,35 @@
+import { Module, Scope } from '@nestjs/common';
+import { UtilsService } from './utils.service';
+import { START_DATE, PRECISION } from './utils.constants';
+
+@Module({
+  providers: [
+    UtilsService,
+    {
+      provide: 'Constants',
+      useValue: {
+        START_DATE,
+        PRECISION,
+      }
+    },
+    {
+      provide: 'DateService',
+      useFactory(constants) {
+        console.log('Date service was created')
+
+        return {
+          getCurrentDate() {
+            return new Date();
+          },
+          getTimeFromStart() {
+            return new Date().getTime() - constants.START_DATE;
+          }
+        }
+      },
+      inject: ['Constants'],
+      scope: Scope.TRANSIENT
+    }
+  ],
+  exports: [UtilsService, 'DateService'],
+})
+export class UtilsModule {}

src/services/utils/utils.service.ts

@@ -0,0 +1,20 @@
+import { Inject, Injectable, Scope } from '@nestjs/common';
+
+@Injectable({ scope: Scope.DEFAULT })
+export class UtilsService {
+  constructor(
+    @Inject('Constants')
+    private readonly constants,
+
+    @Inject('DateService')
+    private readonly dateService,
+  ) {
+    console.log('Utility service was created');
+    console.log(dateService.getTimeFromStart());
+  }
+  average(array: number[]): number {
+    const average = array.reduce((acc, item) => acc + item, 0) / array.length;
+
+    return +average.toFixed(this.constants.PRECISION);
+  }
+}