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MockK development wiki

Fresh development setup

1. git clone git@github.com:mockk/mockk.git
2. install Android SDK (optional)
3. Open in IntelliJ IDEA

Troubleshooting

With few known approaches troubleshooting may be a lot easier.

Transformation dumping

To see results of class transformation(and untransformation) add following system variable:

java  -Dio.mockk.classdump.path=some-directory ...

After running your code transformed class files should appear in some-directory.

Enabling trace logs

Put logback-test.xml in your resources(test-resources) folder:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

    <statusListener class="ch.qos.logback.core.status.NopStatusListener"/>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <layout class="ch.qos.logback.classic.PatternLayout">
            <Pattern>
                %d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n
            </Pattern>
        </layout>
    </appender>

    <root level="trace">
        <appender-ref ref="STDOUT"/>
    </root>

</configuration>

Accessing information in IDEA Debugger

Mock to stub map

((MockKGateway.implementation() as JvmMockKGateway).stubRepo.stubs as JvmWeakConcurrentMap).map

This particular gives access to all stubs, but you may access different other objects from JvmMockKGateway

Proxy maker object

(((MockKGateway.implementation() as JvmMockKGateway).mockFactory as JvmMockFactory).proxyMaker as io.mockk.proxy.jvm.ProxyMaker)

Dispatcher object

Class.forName("io.mockk.proxy.jvm.dispatcher.JvmMockKDispatcher").getDeclaredFields()[0].apply{ isAccessible = true }.get(Class.forName("io.mockk.proxy.jvm.dispatcher.JvmMockKDispatcher"))

Self call eliminator object

(Class.forName("io.mockk.proxy.jvm.advice.SelfCallEliminator").declaredFields[0].apply { isAccessible = true }.get(Class.forName("io.mockk.proxy.jvm.advice.SelfCallEliminator")) as ThreadLocal<*>).get()

Topics

• Basics
  • DSL, Gateway & Agent layers 14:13
  • Mock creation - basic flow 21:14
  • Mock creation - inlining 29:32
  • Mock creation: subclass instrumentation
  • Mock creation: instantiation
  • Mock creation: cancellation
  • (MockK/SpyK creation)
  • mockkObject, mockkStatic, mockkConstructor
  • Mocking by annotation
  • Tests(prinicples & layout)
• Code transformation
  • ByteBuddy inlining
  • ByteBuddy subclassing
  • DEX Maker inlining
  • DEX Maker subclassing
• Call recording
  • Recording states
  • Signatures
  • Autohinting
  • Chain detection
• Verification
  • verify
  • verifyAll
  • verifyOrder
  • verifySequence
  • verify(timeout=X)

Main modules

JVM

• io.mockk:mockk (mockk/jvm)
  JVM MockK implementation
  • io.mockk:mockk-dsl-jvm (dsk/jvm)
    JVM support functions for DSL
  • io.mockk:mockk-common (mockk/common)
    common MockK implementation
    • io.mockk:mockk-dsl (dsl/common)
      common MockK DSL interface
  • io.mockk:mockk-agent-jvm (agennt/jvm)
    call interception for JVM
    • io.mockk:mockk-agent-common (agent/common)
      common call interception code(Android and JVM)
    • io.mockk:mockk-agent-api (agent/common)
      common API(Android and JVM) for call interception
    • org.objenesis:objenesis (2.6)
      library to instantiate objects
    • net.bytebuddy:byte-buddy (1.9.3)
      library to modify byte-code
    • net.bytebuddy:byte-buddy-agent (1.9.3)
      library to modify byte-code on flight

Android instrumented tests

• io.mockk:mockk-android (mockk/android)
  Android implementation is based on JVM(with JVM agent exclusion)
  • io.mockk:mockk (mockk/jvm)
    JVM MockK implementation
    • io.mockk:mockk-common (mockk/common)
      common MockK implementation
      • io.mockk:mockk-dsl (dsl/common)
        common MockK DSL interface
    • io.mockk:mockk-dsl-jvm (dsl/jvm)
      JVM support functions for DSL
  • io.mockk:mockk-agent-android (agent/android)
    call interception for Android (drop-in replacement for mockk-agent-jvm)
    • io.mockk:mockk-agent-common (agent/common)
      common call interception code(Android and JVM)
    • io.mockk:mockk-agent-api (agent/common)
      common API(Android and JVM) for call interception
    • org.objenesis:objenesis (2.6)
      library to instantiate objects
    • com.linkedin.dexmaker:dexmaker (2.12.1)
      library to modify dex-code