Dexmaker

Extension of the Mockito Inline API to allow mocking static methods on the Android Dalvik VM

License

License

Categories

Categories

Mockito Unit Testing Dex General Purpose Libraries Utility
GroupId

GroupId

com.linkedin.dexmaker
ArtifactId

ArtifactId

dexmaker-mockito-inline-extended
Last Version

Last Version

2.28.1
Release Date

Release Date

Type

Type

aar
Description

Description

Dexmaker
Extension of the Mockito Inline API to allow mocking static methods on the Android Dalvik VM
Project URL

Project URL

https://github.com/linkedin/dexmaker
Source Code Management

Source Code Management

https://github.com/linkedin/dexmaker/tree/master

Download dexmaker-mockito-inline-extended

How to add to project

<!-- https://jarcasting.com/artifacts/com.linkedin.dexmaker/dexmaker-mockito-inline-extended/ -->
<dependency>
    <groupId>com.linkedin.dexmaker</groupId>
    <artifactId>dexmaker-mockito-inline-extended</artifactId>
    <version>2.28.1</version>
    <type>aar</type>
</dependency>
// https://jarcasting.com/artifacts/com.linkedin.dexmaker/dexmaker-mockito-inline-extended/
implementation 'com.linkedin.dexmaker:dexmaker-mockito-inline-extended:2.28.1'
// https://jarcasting.com/artifacts/com.linkedin.dexmaker/dexmaker-mockito-inline-extended/
implementation ("com.linkedin.dexmaker:dexmaker-mockito-inline-extended:2.28.1")
'com.linkedin.dexmaker:dexmaker-mockito-inline-extended:aar:2.28.1'
<dependency org="com.linkedin.dexmaker" name="dexmaker-mockito-inline-extended" rev="2.28.1">
  <artifact name="dexmaker-mockito-inline-extended" type="aar" />
</dependency>
@Grapes(
@Grab(group='com.linkedin.dexmaker', module='dexmaker-mockito-inline-extended', version='2.28.1')
)
libraryDependencies += "com.linkedin.dexmaker" % "dexmaker-mockito-inline-extended" % "2.28.1"
[com.linkedin.dexmaker/dexmaker-mockito-inline-extended "2.28.1"]

Dependencies

compile (1)

Group / Artifact Type Version
org.mockito : mockito-core jar 2.28.2

runtime (1)

Group / Artifact Type Version
com.linkedin.dexmaker : dexmaker-mockito-inline jar 2.28.1

Project Modules

There are no modules declared in this project.

Dexmaker

Build Status

A Java-language API for doing compile time or runtime code generation targeting the Dalvik VM. Unlike cglib or ASM, this library creates Dalvik .dex files instead of Java .class files.

It has a small, close-to-the-metal API. This API mirrors the Dalvik bytecode specification giving you tight control over the bytecode emitted. Code is generated instruction-by-instruction; you bring your own abstract syntax tree if you need one. And since it uses Dalvik's dx tool as a backend, you get efficient register allocation and regular/wide instruction selection for free.

What does it do?

Mockito Mocks

Dexmaker lets you use the Mockito mocking library in your Android projects by generating Dalvik bytecode class proxies. Just add an androidTestImplementation dependency on dexmaker-mockito and you can use Mockito in your Android Instrumentation tests.

The version of Mockito that Dexmaker targets can be found in dexmaker-mockito's build.gradle file. The general rule is that the major and minor version of Dexmaker will match the underlying major and minor version of Mockito.

Mocking Final Classes & Methods

Starting in Android "P", it is possible to mock final classes and methods using the dexmaker-mockito-inline library. If you execute your tests on a device or emulator running Android P or above, you can add an androidTestImplementation dependency on dexmaker-mockito-inline (instead of dexmaker-mockito; don't add both) and you can use the normal Mockito APIs to mock final classes and methods in your Android Instrumentation tests.

NOTE: This functionality requires OS APIs which were introduced in Android P and cannot work on older versions of Android.

Class Proxies

Dexmaker includes a stock code generator for class proxies. If you just want to do AOP or class mocking, you don't need to mess around with bytecodes.

Runtime Code Generation

This example generates a class and a method. It then loads that class into the current process and invokes its method.

public final class HelloWorldMaker {
    public static void main(String[] args) throws Exception {
        DexMaker dexMaker = new DexMaker();

        // Generate a HelloWorld class.
        TypeId<?> helloWorld = TypeId.get("LHelloWorld;");
        dexMaker.declare(helloWorld, "HelloWorld.generated", Modifier.PUBLIC, TypeId.OBJECT);
        generateHelloMethod(dexMaker, helloWorld);

        // Create the dex file and load it.
        File outputDir = new File(".");
        ClassLoader loader = dexMaker.generateAndLoad(HelloWorldMaker.class.getClassLoader(),
                outputDir, outputDir);
        Class<?> helloWorldClass = loader.loadClass("HelloWorld");

        // Execute our newly-generated code in-process.
        helloWorldClass.getMethod("hello").invoke(null);
    }

    /**
     * Generates Dalvik bytecode equivalent to the following method.
     *    public static void hello() {
     *        int a = 0xabcd;
     *        int b = 0xaaaa;
     *        int c = a - b;
     *        String s = Integer.toHexString(c);
     *        System.out.println(s);
     *        return;
     *    }
     */
    private static void generateHelloMethod(DexMaker dexMaker, TypeId<?> declaringType) {
        // Lookup some types we'll need along the way.
        TypeId<System> systemType = TypeId.get(System.class);
        TypeId<PrintStream> printStreamType = TypeId.get(PrintStream.class);

        // Identify the 'hello()' method on declaringType.
        MethodId hello = declaringType.getMethod(TypeId.VOID, "hello");

        // Declare that method on the dexMaker. Use the returned Code instance
        // as a builder that we can append instructions to.
        Code code = dexMaker.declare(hello, Modifier.STATIC | Modifier.PUBLIC);

        // Declare all the locals we'll need up front. The API requires this.
        Local<Integer> a = code.newLocal(TypeId.INT);
        Local<Integer> b = code.newLocal(TypeId.INT);
        Local<Integer> c = code.newLocal(TypeId.INT);
        Local<String> s = code.newLocal(TypeId.STRING);
        Local<PrintStream> localSystemOut = code.newLocal(printStreamType);

        // int a = 0xabcd;
        code.loadConstant(a, 0xabcd);

        // int b = 0xaaaa;
        code.loadConstant(b, 0xaaaa);

        // int c = a - b;
        code.op(BinaryOp.SUBTRACT, c, a, b);

        // String s = Integer.toHexString(c);
        MethodId<Integer, String> toHexString
                = TypeId.get(Integer.class).getMethod(TypeId.STRING, "toHexString", TypeId.INT);
        code.invokeStatic(toHexString, s, c);

        // System.out.println(s);
        FieldId<System, PrintStream> systemOutField = systemType.getField(printStreamType, "out");
        code.sget(systemOutField, localSystemOut);
        MethodId<PrintStream, Void> printlnMethod = printStreamType.getMethod(
                TypeId.VOID, "println", TypeId.STRING);
        code.invokeVirtual(printlnMethod, null, localSystemOut, s);

        // return;
        code.returnVoid();
    }
}

Download

For Mockito support, download the latest .jar via Maven:

    <dependency>
      <groupId>com.linkedin.dexmaker</groupId>
      <artifactId>dexmaker-mockito</artifactId>
      <version>2.28.1</version>
      <type>pom</type>
    </dependency>

or Gradle:

    androidTestImplementation 'com.linkedin.dexmaker:dexmaker-mockito:2.28.1'

Note: The dependency on Mockito will be transitively included, so there's no need to specify both Mockito AND dexmaker-mockito

Snapshots

You can use snapshot builds to test the latest unreleased changes. A new snapshot is published after every merge to the main branch by the Deploy Snapshot Github Action workflow.

Just add the Sonatype snapshot repository to your Gradle scripts:

repositories {
    maven {
        url "https://oss.sonatype.org/content/repositories/snapshots/"
    }
}

You can find the latest snapshot version to use in the gradle.properties file.

com.linkedin.dexmaker

LinkedIn

Versions

Version
2.28.1