README.md

Mock4k

Super-simple and super-fast Mocking library. Use when you really don't want to import an entire mocking library to slow down your build, or just want some simple replacement of an interface.

Core features:

• ✅ Simple
• ✅ Fast
• ✅ Relaxed/Strict modes
• ✅ Coroutines
• ✅ Functions
• ❌ Verification
• ❌ Argument capture
• ❌ Partial mocking
• ❌ Spies
• ❌ Any evil Powermock nonsense

Supplementary features:

• ❌ Spring-support
• ❌ Multiplatform
• ❌ Annotations
• ❌ Blockchain
• ❌ AI-powered

Installation

In Gradle, install the ForkHandles BOM and then this module in the dependency block:

implementation(platform("dev.forkhandles:forkhandles-bom:X.Y.Z"))
implementation("dev.forkhandles:mock4k")

Usage

Import from dev.forkhandles.mock4k, then apply the unique delegate'n'stub technique. (patent pending).

interface Wallet {
    fun pay(item: String, coins: Int): Int?
}

class AppleStore(private val wallet: Wallet) {
    fun buyMacBook() = wallet.pay("MacBook", 9999)
    suspend fun seeGenius() = "hello!"
    fun buyMacbookUsing(pay: (String, Int) -> Int?) = pay("MacBook", 9999)
}

class AppleStoreTest {
    @Test
    fun `buy macbook in strict mode`() {
        // when there are calls expected you can delegate'n'stub
        val appleStore = AppleStore(object : Wallet by mock() {
            override fun pay(item: String, coins: Int): Int? {
                assertThat(item, equalTo("MacBook"))
                assertThat(coins, equalTo(9999))
                return -9999
            }
        })
        assertThat(appleStore.buyMacBook(), equalTo(-9999))
    }

    @Test
    fun `buy macbook in relaxed mode`() {
        // relaxed mode returns null by default
        val appleStore = AppleStore(mock(MockMode.Relaxed))
        assertThat(appleStore.buyMacBook(), equalTo(null))
    }
   
    @Test
    fun `see genius`() {
        val appleStore = AppleStore(mock())

        runBlocking {
            // suspend calls
            assertThat(appleStore.seeGenius(), equalTo("hello!"))
        }
    }

    @Test
    fun `bus using someone else's money`() {
        val appleStore = AppleStore(mock())
        appleStore.buyMacbookUsing(mock())
    }
}

Thanks to:

• All contributors
• Inspired by left-pad