get project by tag use case

src/repositories/in-memory-db/inMemoryProjectRepository.ts

@@ -40,4 +40,12 @@ export class InMemoryProjectRepository implements ProjectRepository {
     }
     return project
   }
+
+  async fetchProjectByTags(tags: string[]): Promise<Project[]> {
+    const projects = this.dbProject.filter((project) =>
+      project.tags.some((tag) => tags.includes(tag)),
+    )
+
+    return projects
+  }
 }

src/repositories/prisma/prisma-project-repository.ts

@@ -30,4 +30,8 @@ export class PrismaProjectRepository implements ProjectRepository {
 
     return project
   }
+
+  async fetchProjectByTags(tags: string[]): Promise<Project[]> {
+    throw new Error('Method not implemented.')
+  }
 }

src/repositories/project-repository.ts

@@ -4,4 +4,5 @@ export interface ProjectRepository {
   create(data: Prisma.ProjectUncheckedCreateInput): Promise<Project>
   fetchProjectsByUserId(userId: string): Promise<Project[]>
   fetchProjectById(projectId: string): Promise<Project | null>
+  fetchProjectByTags(tags: string[]): Promise<Project[]>
 }

src/use-cases/getProjetsByTagsUseCase.spec.ts

@@ -0,0 +1,157 @@
+import { expect, describe, it, beforeEach } from 'vitest'
+
+import { InMemoryProjectRepository } from '../repositories/in-memory-db/inMemoryProjectRepository'
+
+import { ProjectRepository } from '../repositories/project-repository'
+import { GetProjectsByTagsUseCase } from './getProjetsByTagsUseCase'
+
+let projectRepository: ProjectRepository
+let getProjectsByTagsUseCase: GetProjectsByTagsUseCase
+
+describe('Get Project By Tags', () => {
+  beforeEach(() => {
+    projectRepository = new InMemoryProjectRepository()
+    getProjectsByTagsUseCase = new GetProjectsByTagsUseCase(projectRepository)
+  })
+
+  it('should be able get projects that include a tag', async () => {
+    await projectRepository.create({
+      title: 'React Typescript 1',
+      description: 'Best Project',
+      tags: ['react', 'node'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 2',
+      description: 'Best Project 2',
+      tags: ['react', 'node', 'typescript'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    const { projects } = await getProjectsByTagsUseCase.execute({
+      projectTags: ['typescript'],
+    })
+
+    expect(projects).toHaveLength(1)
+    expect(projects[0]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 2' }),
+    )
+
+    expect(projects[0]).toEqual(
+      expect.objectContaining({ tags: ['react', 'node', 'typescript'] }),
+    )
+  })
+
+  it('Should be able to get projects that include some tags without duplicating the results.', async () => {
+    await projectRepository.create({
+      title: 'React Typescript 1',
+      description: 'Best Project',
+      tags: ['react', 'node'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 2',
+      description: 'Best Project 2',
+      tags: ['react', 'node', 'typescript'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 3',
+      description: 'Best Project 2',
+      tags: ['react', 'node'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    const { projects } = await getProjectsByTagsUseCase.execute({
+      projectTags: ['react', 'node'],
+    })
+
+    expect(projects).toHaveLength(3)
+    expect(projects[0]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 1' }),
+    )
+
+    expect(projects[1]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 2' }),
+    )
+
+    expect(projects[2]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 3' }),
+    )
+  })
+
+  it('Should be able to get projects that include tags NOT being case sensitive', async () => {
+    await projectRepository.create({
+      title: 'React Typescript 1',
+      description: 'Best Project',
+      tags: ['react', 'node'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 2',
+      description: 'Best Project 2',
+      tags: ['react', 'node', 'typescript'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 3',
+      description: 'Best Project 2',
+      tags: ['react', 'node'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    const { projects } = await getProjectsByTagsUseCase.execute({
+      projectTags: ['REACT', 'NODE'],
+    })
+
+    expect(projects).toHaveLength(3)
+    expect(projects[0]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 1' }),
+    )
+
+    expect(projects[1]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 2' }),
+    )
+
+    expect(projects[2]).toEqual(
+      expect.objectContaining({ title: 'React Typescript 3' }),
+    )
+  })
+
+  it('should not be able to get a project if the tag was not registered', async () => {
+    await projectRepository.create({
+      title: 'React Typescript 1',
+      description: 'Best Project',
+      tags: ['tag'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    await projectRepository.create({
+      title: 'React Typescript 2',
+      description: 'Best Project 2',
+      tags: ['tag'],
+      link: 'https://github.com/luiseduardo3/nodets-petcanil',
+      user_id: 'user_id',
+    })
+
+    const { projects } = await getProjectsByTagsUseCase.execute({
+      projectTags: ['react', 'node'],
+    })
+
+    expect(projects).toHaveLength(0)
+  })
+})

src/use-cases/getProjetsByTagsUseCase.ts

@@ -0,0 +1,30 @@
+import { Project } from '@prisma/client'
+
+import { ProjectRepository } from '../repositories/project-repository'
+
+import { ResourceNotFoundError } from './errors/ResourceNotFoundError'
+
+interface GetProjectsByTagsRequest {
+  projectTags: string[]
+}
+
+interface GetProjectsByTagsResponse {
+  projects: Project[]
+}
+
+export class GetProjectsByTagsUseCase {
+  constructor(private projectRepository: ProjectRepository) {}
+
+  async execute({
+    projectTags,
+  }: GetProjectsByTagsRequest): Promise<GetProjectsByTagsResponse> {
+    const lowercaseTags = projectTags.map((tag) => tag.toLowerCase())
+
+    const projects =
+      await this.projectRepository.fetchProjectByTags(lowercaseTags)
+
+    return {
+      projects,
+    }
+  }
+}