Reference · Testing

Jenis test dan test double

Ringkasan satu halaman. Dari Lesson 0010.

Testing pyramid

Jenis	Menguji	Jumlah	Node
Unit Test	Satu komponen terisolasi (`ProductService`), I/O diganti test double. Fast, Isolated, Repeatable, Self-Checking, Timely ^[2]	Paling banyak	Jest + `jest.fn()`
Integration Test	"two or more app components work together": pipeline HTTP → Controller → Service → DB ^[1]	Sedikit, skenario infrastruktur penting	Supertest
E2E	Browser Angular sampai database	Paling sedikit (lambat, flaky) ^[4]	Playwright / Cypress

Aturan: "If a behavior can be tested using either a unit test or an integration test, choose the unit test." ^[1]

Test double ^[3]

Istilah	Peran	Moq	Jest
Stub	Jawaban siap; tidak di-assert	`Setup(...).ReturnsAsync(x)`	`mockReturnValue`
Mock	Panggilannya diverifikasi (behavior verification) ^[5]	`Verify(..., Times.Never())`	`toHaveBeenCalled`
Fake	Implementasi kerja dengan jalan pintas	SQLite in-memory	Repository berbasis array
Dummy	Hanya mengisi parameter	`Mock.Of<ILogger<T>>()`	`{}`

new Mock<T>() tanpa Verify berperan sebagai stub. Dokumen .NET memakai "fake" sebagai istilah umum (stub atau mock). ^[2]

`WebApplicationFactory<Program>` ^[1]

Paket Microsoft.AspNetCore.Mvc.Testing; menjalankan app di TestServer in-memory, tanpa deploy.
public partial class Program { } di Program.cs supaya test project bisa memakai Program (atau InternalsVisibleTo).
CreateClient() → HttpClient ke TestServer. IClassFixture<ApiFactory> berbagi factory per class.
Override ConfigureWebHost → builder.ConfigureServices (jalan setelah Program.cs) untuk mengganti DbContext.
Per test: WithWebHostBuilder(b => b.ConfigureTestServices(...)).

Apa yang di-mock

Ya	Tidak
Batas I/O: `IProductRepository`, HTTP client keluar, jam sistem	Entity/DTO, SUT, method private, `DbSet` untuk query (LINQ = extension method statis) ^[9]

Database test (saran EF Core ^[9]): DB produksi asli (Testcontainers) → repository pattern → SQLite in-memory (beda dialek, case-sensitive) → hindari provider EF Core in-memory.

Jawaban 60 detik

Jenis test: unit = satu komponen terisolasi, I/O di-mock, milidetik; integration = beberapa komponen bersama sampai DB; E2E = dari UI. Piramida: makin tinggi makin sedikit. API diuji dengan WebApplicationFactory (TestServer in-memory, CreateClient), DbContext diganti SQLite/Testcontainers.

Test double: stub = jawaban siap, tidak di-assert; mock = panggilannya di-Verify; fake = implementasi ringan (SQLite in-memory). Mock batas I/O; jangan mock Entity/DTO, SUT, method private, atau DbSet untuk query.

Sumber: [1] Microsoft Learn: Integration tests in ASP.NET Core · [2] Microsoft Learn: Unit testing best practices · [3] Martin Fowler: TestDouble · [4] The Practical Test Pyramid · [5] Martin Fowler: Mocks Aren't Stubs · [9] EF Core: Choosing a testing strategy