Dependency on a module on a multimodule gradle project

Question

I have a multi-module project in Gradle.

I refactored the common functionality into a module named common.

I have tests in a different module (lets say module A) of the multi-module project that consume the classes under src/main/java of the common module.

I am able to import these classes from common module in test classes of module A, but when I run the tests, I get the following error:

error: package 'common.bla...' does not exist.

This is the build.gradle file for module A that depends on common module for its tests (I have tried all these options):

 dependencies  {
     compile project(':common')
     testCompile project(':common')
     testRuntime project(':common')
     runtime project(':common')
     implementation project(":common")
     testCompile 'junit:junit:4.12'
     testImplementation 'junit:junit:4.12'
     implementation 'junit:junit:4.12'
     testCompileOnly project(':common')
     testRuntimeOnly project(':common')
     testImplementation project(':common')
     runtimeOnly project(':common')
     testCompile project(":common").sourceSets.test.output
     compile project(":common").sourceSets.test.output
     testRuntime fileTree(dir: 'libs', include: ['*.jar'])
}

I have also verified that a jar is created in common/build/libs.
What else can I try?

Answer 1

It’s a bit difficult to answer your question with so little context but let me try to do it anyway. From what I understand, you have a directory structure similar to the following (excluding the Gradle Wrapper files):

.
├── common
│   ├── build.gradle
│   └── src
│       └── main
│           └── java
│               └── common
│                   └── Foobar.java
├── moduleA
│   ├── build.gradle
│   └── src
│       └── test
│           └── java
│               └── FoobarTest.java
└── settings.gradle

I can successfully run ./gradlew :moduleA:test (Gradle 5.6.2) from the root directory with the following file contents:

./common/build.gradle

plugins {
    id 'java'
}

./common/src/main/java/common/Foobar.java

package common;

public class Foobar {
    public static void main(String... args) {
        System.err.println("Foobar");
    }
}

./moduleA/build.gradle

plugins {
    id 'java'
}

repositories {
    jcenter()
}

dependencies {
    testImplementation project(':common')
    testImplementation 'junit:junit:4.12'
}

./moduleA/src/test/java/FoobarTest.java

import common.Foobar;

public class FoobarTest {

    @org.junit.Test
    public void myTest() {
        org.junit.Assert.assertNotNull(Foobar.class);
    }
}

./settings.gradle

include 'common', 'moduleA'

---

As said, it’s hard to say where exactly your error comes from. If you can’t use my minimal setup to get your own code fixed, then maybe try to update your question with a minimal, reproducible example for your non-working setup.