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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

Main modules

Most of MockK implementation is based on the multi-platform code. Few attempts were made to extend it to JS and Native platforms, but so far only JVM and AIT(Android instrumented test) are supported.

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

Troubleshooting

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="debug">
        <appender-ref ref="STDOUT"/>
    </root>

</configuration>

Accessing information in IDEA Debugger

Just use the following expression:

((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

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)