added categories resource

src/app.module.ts

@@ -5,19 +5,22 @@ import { TypeOrmModule, TypeOrmModuleOptions } from '@nestjs/typeorm';
 import { Merchant } from './merchants/entities/merchant.entity';
 import { TagsModule } from './tags/tags.module';
 import { Tag } from './tags/entities/tag.entity';
+import { CategoriesModule } from './categories/categories.module';
+import { Category } from './categories/entities/category.entity';
 
 const sqliteConfig: TypeOrmModuleOptions = {
   synchronize: true, // typeorm -h (schema:sync)
   type: 'sqlite',
   database: 'common-cents.db',
-  entities: [Merchant, Tag]
+  entities: [Merchant, Tag, Category]
 }
 
 @Module({
   imports: [
     TypeOrmModule.forRoot(sqliteConfig),
     MerchantsModule,
-    TagsModule
+    TagsModule,
+    CategoriesModule
   ],
   controllers: [AppController],
   providers: []

src/categories/categories.controller.ts

@@ -0,0 +1,75 @@
+import {
+  Controller,
+  Get,
+  Post,
+  Put,
+  Delete,
+  Body,
+  Param,
+  HttpCode,
+  HttpStatus,
+  BadRequestException,
+  NotFoundException,
+  InternalServerErrorException
+} from '@nestjs/common';
+import { CategoriesService } from './categories.service';
+import { CreateCategoryDto } from './dto/create-category.dto';
+import { UpdateCategoryDto } from './dto/update-category.dto';
+import { Category } from './entities/category.entity';
+
+@Controller('categories')
+export class CategoriesController {
+  constructor(private readonly categoriesService: CategoriesService) { }
+
+  @Get()
+  @HttpCode(HttpStatus.OK)
+  public async findAll(): Promise<Category[]> {
+    return await this.categoriesService.findAll();
+  }
+
+  @Get(':id')
+  @HttpCode(HttpStatus.OK)
+  public async findOne(@Param('id') id: string): Promise<Category> {
+    if (!id) {
+      throw new BadRequestException('No ID provided.');
+    }
+
+    try {
+      return await this.categoriesService.findById(id);
+    }
+    catch (error) {
+      throw new NotFoundException(error);
+    }
+  }
+
+  @Post()
+  @HttpCode(HttpStatus.CREATED)
+  public async create(@Body() category: CreateCategoryDto): Promise<Category> {
+    if (!category.name) {
+      throw new BadRequestException('Category name cannot be empty.');
+    }
+
+    try {
+      return this.categoriesService.create(category);
+    }
+    catch (error) {
+      throw new InternalServerErrorException(error);
+    }
+  }
+
+  @Put()
+  @HttpCode(HttpStatus.OK)
+  public async update(@Body() category: UpdateCategoryDto): Promise<Category> {
+    if (!category.id) {
+      throw new BadRequestException('Category ID cannot be empty.');
+    }
+
+    return await this.categoriesService.update(category);
+  }
+
+  @Delete(':id')
+  @HttpCode(HttpStatus.NO_CONTENT)
+  public async remove(@Param('id') id: string): Promise<void> {
+    return await this.categoriesService.remove(id);
+  }
+}

src/categories/categories.module.ts

@@ -0,0 +1,10 @@
+import { Module } from '@nestjs/common';
+import { CategoriesService } from './categories.service';
+import { CategoriesController } from './categories.controller';
+import { CategoryDataService } from './category-data.service';
+
+@Module({
+  controllers: [CategoriesController],
+  providers: [CategoriesService, CategoryDataService]
+})
+export class CategoriesModule { }

src/categories/categories.service.ts

@@ -0,0 +1,35 @@
+import { Injectable } from '@nestjs/common';
+import { CreateCategoryDto } from './dto/create-category.dto';
+import { UpdateCategoryDto } from './dto/update-category.dto';
+import { CategoryDataService } from './category-data.service';
+import { Category } from './entities/category.entity';
+
+@Injectable()
+export class CategoriesService {
+  public constructor(private categoryDataService: CategoryDataService) { }
+
+  public async findAll(): Promise<Category[]> {
+    return await this.categoryDataService.getAll();
+  }
+
+  public async findById(id: string): Promise<Category> {
+    const category = await this.categoryDataService.getById(id);
+    if (!category) {
+      throw new Error('No category found');
+    }
+
+    return category;
+  }
+
+  public async create(category: CreateCategoryDto): Promise<Category> {
+    return await this.categoryDataService.create(category.name);
+  }
+
+  public async update(category: UpdateCategoryDto): Promise<Category> {
+    return await this.categoryDataService.update(category);
+  }
+
+  public async remove(id: string): Promise<void> {
+    await this.categoryDataService.delete(id);
+  }
+}

src/categories/category-data.service.ts

@@ -0,0 +1,33 @@
+import { Injectable } from '@nestjs/common';
+import { DataSource, Repository } from 'typeorm';
+import { Category } from './entities/category.entity';
+import { UpdateCategoryDto } from './dto/update-category.dto';
+
+@Injectable()
+export class CategoryDataService {
+  private categories: Repository<Category>;
+
+  public constructor(private dataSource: DataSource) {
+    this.categories = this.dataSource.getRepository(Category);
+  }
+
+  public async getAll(): Promise<Category[]> {
+    return await this.categories.find();
+  }
+
+  public async getById(id: string): Promise<Category | null> {
+    return await this.categories.findOneBy({ id });
+  }
+
+  public async create(name: string): Promise<Category> {
+    return await this.categories.save({ name });
+  }
+
+  public async update(category: UpdateCategoryDto): Promise<Category> {
+    return await this.categories.save(category);
+  }
+
+  public async delete(id: string): Promise<void> {
+    await this.categories.delete({ id });
+  }
+}

src/categories/dto/create-category.dto.ts

@@ -0,0 +1,3 @@
+export class CreateCategoryDto {
+  name: string;
+}

src/categories/dto/update-category.dto.ts

@@ -0,0 +1,4 @@
+export class UpdateCategoryDto {
+  id: string;
+  name: string;
+}

src/categories/entities/category.entity.ts

@@ -0,0 +1 @@
+export class Category {}