srcdeps

# A binary dependency pulled from rubygems.org
gem 'rack', '2.0.1'

# A source dependency built by Blunder
# from a git commit
gem 'rack',
    :git => 'https://github.com/rack/rack.git',
    :ref => '0bd839d'

// A binary dependency
libraryDependencies +=
    "com.typesafe.play" %% "play-slick" % "2.0.2"

// A source dependency
myProject
  .dependsOn(
    ProjectRef(
      uri("git://github.com/freekh/play-slick.git#v1.2.3")
      "play-slick"
    )
  )

configModelVersion: 2.3  # srcdeps.yaml file
repositories:
  org.mygroup:    # a repository ID
    includes:
    - org.mygroup # a groupId[:artifactId[:version]] pattern
                  # may contain * wildcards
    urls:
    - git:https://github.com/ppalaga/junit4.git

    # The git ref to build
    buildRef: revision-abcd1234

    # trigger source build only for versions matching this pattern
    buildVersionPattern: .*-SNAPSHOT

public class Demo {
  public String sayHello() {
    return "Hello World!";
  }
}

public class DemoTest {
  @Test
  public void sayHelloTest() {
    Assert.assertEquals("Hello World!", new Demo().sayHello());
  }
}

public class Demo {
  public String sayHello() {
    return "Hello World!";
  }
}

public class DemoTest {
  @Test
  public void sayHelloTest() {
    Assert.assertHelloJcon(new Demo().sayHello());
    //      ⬑ not available in the stock jUnit :(
  }
}

public class Assert {

  // Add the new method to org.junit.Assert
  public static void assertHelloJcon(String actual) {
    assertEquals(
      "Not the right conference!!!",
      "Hello JCON!", actual
    );
  }
...

mvn org.srcdeps.mvn:srcdeps-maven-plugin:3.3.2:init

<extensions>
  <extension>
    <groupId>org.srcdeps.mvn</groupId>
    <artifactId>srcdeps-maven-local-repository</artifactId>
    <version>3.3.2</version>
  </extension>
</extensions>

configModelVersion: 2.3
repositories:
  junit:
    includes:
    - junit # a groupId[:artifactId[:version]] pattern
            # may contain * wildcards
    urls:
    - git:https://github.com/ppalaga/junit4.git
    buildRef: revision-26d7205c48b7c28b278de403a0473cd9e4bee90b
    buildVersionPattern: .*-srcdeps

...
<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <scope>test</scope>
  <version>4.13-srcdeps</version><!-- -srcdeps suffix to match -->
                                 <!--  buildVersionPattern     -->
                                 <!--  in srcdeps.yaml         -->
</dependency>
...

cd srcdeps-demo
mvn clean test
...
Failed tests:
  sayHelloTest(org.srcdeps.DemoTest): Not the right conference!
    expected:<Hello [JCON]!> but was:<Hello [World]!>
...

cd srcdeps-demo
mvn clean test
...
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
...
BUILD SUCCESS

public class Hello  {
    public String greet()  {
        return "Hello from a Gradle dependency!";
    }
}

public class HelloTest {
    @Test
    public void greet() {
        Assert.assertEquals("Hello from a Gradle dependency!", new Hello().greet());
    }
}

// settings.gradle
sourceControl {
    gitRepository("https://github.com/ppalaga/181011-hello-gradle.git") {
        producesModule("org.srcdeps.hello:hello-gradle")
    }
}

// build.gradle
dependencies {
    implementation('org.srcdeps.hello:hello-gradle') {
        version {
            branch = 'master'
        }
    }
}

<repositories>
  <repository>
     <id>jitpack.io</id>
     <url>https://jitpack.io</url>
  </repository>
</repositories>