feat: support loan books

prisma/migrations/20231111180728_initial/migration.sql

@@ -33,6 +33,7 @@ CREATE TABLE "User" (
     "email" TEXT,
     "emailVerified" TIMESTAMP(3),
     "image" TEXT,
+    "version" INTEGER NOT NULL DEFAULT 0,
 
     CONSTRAINT "User_pkey" PRIMARY KEY ("id")
 );

prisma/migrations/20231122133945_book/migration.sql

@@ -1,9 +1,14 @@
+-- CreateEnum
+CREATE TYPE "BookState" AS ENUM ('AVAILABLE', 'LOANED');
+
 -- CreateTable
 CREATE TABLE "Book" (
     "id" TEXT NOT NULL,
     "authors" TEXT[],
     "image" TEXT NOT NULL,
     "title" TEXT NOT NULL,
+    "version" INTEGER NOT NULL DEFAULT 0,
+    "state" "BookState" NOT NULL DEFAULT 'AVAILABLE',
 
     CONSTRAINT "Book_pkey" PRIMARY KEY ("id")
 );

prisma/migrations/20231203103508_loans/migration.sql

@@ -0,0 +1,37 @@
+-- CreateTable
+CREATE TABLE "Loan" (
+    "id" TEXT NOT NULL,
+    "version" INTEGER NOT NULL DEFAULT 0,
+    "startsAt" TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "userId" TEXT NOT NULL,
+    "bookId" TEXT NOT NULL,
+
+    CONSTRAINT "Loan_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateTable
+CREATE TABLE "LoanRegistry" (
+    "id" TEXT NOT NULL,
+    "version" INTEGER NOT NULL DEFAULT 0,
+    "startsAt" TIMESTAMPTZ NOT NULL,
+    "finishedAt" TIMESTAMPTZ NOT NULL,
+    "userId" TEXT NOT NULL,
+    "bookId" TEXT NOT NULL,
+
+    CONSTRAINT "LoanRegistry_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "Loan_bookId_key" ON "Loan"("bookId");
+
+-- AddForeignKey
+ALTER TABLE "Loan" ADD CONSTRAINT "Loan_userId_fkey" FOREIGN KEY ("userId") REFERENCES "User"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "Loan" ADD CONSTRAINT "Loan_bookId_fkey" FOREIGN KEY ("bookId") REFERENCES "Book"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "LoanRegistry" ADD CONSTRAINT "LoanRegistry_userId_fkey" FOREIGN KEY ("userId") REFERENCES "User"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "LoanRegistry" ADD CONSTRAINT "LoanRegistry_bookId_fkey" FOREIGN KEY ("bookId") REFERENCES "Book"("id") ON DELETE RESTRICT ON UPDATE CASCADE;

prisma/schema.prisma

@@ -36,15 +36,17 @@ model Session {
 }
 
 model User {
-  id            String    @id @default(cuid())
+  id            String         @id @default(cuid())
+  version       Int            @default(0)
   name          String?
-  email         String?   @unique
+  email         String?        @unique
   emailVerified DateTime?
   image         String?
-  roles         String[]  @default(["ROLE_USER"])
+  roles         String[]       @default(["ROLE_USER"])
   accounts      Account[]
   sessions      Session[]
   Loan          Loan[]
+  LoanRegistry  LoanRegistry[]
 }
 
 model VerificationToken {
@@ -55,23 +57,41 @@ model VerificationToken {
   @@unique([identifier, token])
 }
 
+model Book {
+  id           String         @id @default(cuid())
+  version      Int            @default(0)
+  authors      String[]
+  image        String
+  title        String
+  state        BookState      @default(AVAILABLE)
+  loan         Loan?
+  loanRegistry LoanRegistry[]
+}
+
 model Loan {
-  id         String    @id @default(cuid())
-  startsAt   DateTime  @default(now())
-  finishedAt DateTime?
-  user       User      @relation(fields: [userId], references: [id])
+  id       String   @id @default(cuid())
+  version  Int      @default(0)
+  startsAt DateTime @default(now()) @db.Timestamptz()
+  user     User     @relation(fields: [userId], references: [id])
+  userId   String
+  book     Book     @relation(fields: [bookId], references: [id])
+  bookId   String
+
+  @@unique([bookId])
+}
+
+model LoanRegistry {
+  id         String   @id @default(cuid())
+  version    Int      @default(0)
+  startsAt   DateTime @db.Timestamptz()
+  finishedAt DateTime @db.Timestamptz()
+  user       User     @relation(fields: [userId], references: [id])
   userId     String
-  book       Book      @relation("Loans", fields: [bookId], references: [id])
+  book       Book     @relation(fields: [bookId], references: [id])
   bookId     String
-  activeLoan Book?     @relation("ActiveLoan") @ignore
 }
 
-model Book {
-  id           String   @id @default(cuid())
-  authors      String[]
-  image        String
-  title        String
-  Loan         Loan[]   @relation("Loans")
-  activeLoan   Loan?    @relation("ActiveLoan", fields: [activeLoanId], references: [id])
-  activeLoanId String?  @unique
+enum BookState {
+  AVAILABLE
+  LOANED
 }

src/core/book/application/__tests__/create-book.use-case.spec.ts

@@ -0,0 +1,53 @@
+import { describe, expect, it } from 'vitest'
+
+import CreateBookUseCase from '@/core/book/application/create-book.use-case'
+import BooksInMemory from '@/core/book/infrastructure/services/books-in-memory.repository'
+import DuplicateIdError from '@/core/common/domain/errors/application/duplicate-id-error'
+import unexpected from '@/lib/utils/unexpected'
+import BooksExamples from '@/tests/examples/books.examples'
+import bookRequestExamples from '@/tests/examples/books-request.examples'
+
+describe('CreateBookUseCase', () => {
+  it('should create a new book', async () => {
+    // Arrange
+    const books = new BooksInMemory()
+
+    const command = bookRequestExamples.create()
+    const useCase = new CreateBookUseCase(books)
+
+    // Act
+    const result = await useCase.with(command)
+
+    // Assert
+    result.match(
+      () => {
+        const savedBook = books.books.get(command.id)
+        expect(savedBook?.version).toEqual(0)
+      },
+      (error) => unexpected.error(error),
+    )
+  })
+
+  it('should rejects to create a book with the same id', async () => {
+    // Arrange
+    const book = BooksExamples.available()
+    const books = new BooksInMemory([book])
+
+    const command = {
+      ...bookRequestExamples.create(),
+      id: book.id.value,
+    }
+    const useCase = new CreateBookUseCase(books)
+
+    // Act
+    const result = await useCase.with(command)
+
+    // Assert
+    result.match(
+      (success) => unexpected.success(success),
+      (error) => {
+        expect(error).toBeInstanceOf(DuplicateIdError)
+      },
+    )
+  })
+})

src/core/book/application/__tests__/loan-book.use-case.spec.ts

@@ -0,0 +1,73 @@
+import { describe, expect, it } from 'vitest'
+
+import { LoanBookUseCase } from '@/core/book/application/loan-book-use.case'
+import LoanBookRequest from '@/core/book/dto/requests/loan-book.request'
+import BooksInMemory from '@/core/book/infrastructure/services/books-in-memory.repository'
+import ApplicationError from '@/core/common/domain/errors/application-error'
+import LoanBookService from '@/core/loan/domain/services/loan-book.service'
+import LoansInMemory from '@/core/loan/infrastructure/services/loans-in-memory.repository'
+import unexpected from '@/lib/utils/unexpected'
+import BooksExamples from '@/tests/examples/books.examples'
+import LoansExamples from '@/tests/examples/loans.examples'
+import UsersExamples from '@/tests/examples/users.examples'
+
+describe('Loan book', () => {
+  it('should loan a available book to a user', async () => {
+    // Arrange
+    const book = BooksExamples.available()
+    const books = new BooksInMemory([book])
+
+    const user = UsersExamples.basic()
+
+    const loans = new LoansInMemory([])
+
+    const loanBookService = new LoanBookService(loans)
+
+    const useCase = new LoanBookUseCase(books, loanBookService)
+    const request = LoanBookRequest.with({
+      bookId: book.id.value,
+      userId: user.id.value,
+    })
+
+    // Act
+    const result = useCase.with(request)
+
+    // Assert
+    await result.match(
+      () => {
+        expect(loans.loans).toHaveLength(1)
+      },
+      (error) => unexpected.error(error),
+    )
+  })
+
+  it('should not loan an unavailable book to a user', async () => {
+    // Arrange
+    const book = BooksExamples.loaned()
+    const books = new BooksInMemory([book])
+
+    const user = UsersExamples.basic()
+
+    const loan = LoansExamples.ofBookAndUser(book, user)
+    const loans = new LoansInMemory([loan])
+
+    const loanBookService = new LoanBookService(loans)
+
+    const useCase = new LoanBookUseCase(books, loanBookService)
+    const request = LoanBookRequest.with({
+      bookId: book.id.value,
+      userId: user.id.value,
+    })
+
+    // Act
+    const result = useCase.with(request)
+
+    // Assert
+    await result.match(
+      (_ok) => unexpected.success(_ok),
+      (_error) => {
+        expect(_error).instanceof(ApplicationError)
+      },
+    )
+  })
+})

src/core/book/application/__tests__/return-book.use-case.spec.ts

@@ -0,0 +1,42 @@
+import { describe, expect, it } from 'vitest'
+
+import ReturnBookUseCase from '@/core/book/application/return-book.use-case'
+import ReturnBookRequest from '@/core/book/dto/requests/return-book.request'
+import BooksInMemory from '@/core/book/infrastructure/services/books-in-memory.repository'
+import ReturnBookService from '@/core/loan/domain/services/return-book.service'
+import LoansInMemory from '@/core/loan/infrastructure/services/loans-in-memory.repository'
+import unexpected from '@/lib/utils/unexpected'
+import BooksExamples from '@/tests/examples/books.examples'
+import LoansExamples from '@/tests/examples/loans.examples'
+import UsersExamples from '@/tests/examples/users.examples'
+
+describe('Return book', () => {
+  it('should return a loaned book', async () => {
+    // Arrange
+    const book = BooksExamples.loaned()
+    const books = new BooksInMemory([book])
+
+    const user = UsersExamples.basic()
+
+    const loan = LoansExamples.ofBookAndUser(book, user)
+    const loans = new LoansInMemory([loan])
+
+    const returnBookService = new ReturnBookService(loans)
+
+    const useCase = new ReturnBookUseCase(books, returnBookService)
+    const request = ReturnBookRequest.with({
+      bookId: book.id.value,
+    })
+
+    // Act
+    const result = useCase.with(request)
+
+    // Assert
+    await result.match(
+      () => {
+        expect(loans.loans).toHaveLength(0)
+      },
+      (error) => unexpected.error(error),
+    )
+  })
+})