Why gradle resolve dependencies in the module name order by default?

I've got three modules:

• amodule
• bmodule
• cmodule

There are integration-tests in all of these three modules. The bmodule is the base - it contains BaseClass, which I want to use in integration-tests in amodule and cmodule

The example of my project is on github: https://github.com/ljql/test-deps

I try to add dependency to integration-tests of bmodule in amodule and cmodule.
File build.gradle looks the same in modules amodule and cmodule

sourceSets {
    intTest {
        java {
            srcDir 'src/test-integration/java'
        }
        resources {
            srcDir 'src/test-integration/resources'
        }
        compileClasspath += rootProject.project('bmodule').sourceSets.intTest.output
        runtimeClasspath += rootProject.project('bmodule').sourceSets.intTest.output
    }
}

configurations {
    intTestCompile {
        extendsFrom compile
    }
    intTestRuntime {
        extendsFrom runtime
    }
}

dependencies {
    intTestCompile project(path: ':bmodule', configuration:  'intTestCompile')
}

But when I try to build amodule I've got an error:

Build file '/test-deps/amodule/build.gradle' line: 10

A problem occurred evaluating project ':amodule'.
> Could not get unknown property 'intTest' for SourceSet container of type org.gradle.api.internal.tasks.DefaultSourceSetContainer.

The build of cmodule, which is the copy of amodule, is completed successfully.

The only difference between amodule and cmodule is in their names. The amodule precedes the bmodule and the cmodule followed by the bmodule

How can I specify a sequence of gradle resolve dependencies in my case? I want gradle to find out about the bmodule first and then about the amodule and the cmodule

Try putting this in the your amdoule's build.gradle

preBuild.dependsOn ":bmodule:build"

You have a project evaluation ordering problem. Since both amodule and cmodule expect to find specific components of bmodule, you need to ask Gradle to make sure bmodule has been evaluated first.

You can add in the build files of amodule and cmodule the following:

evaluationDependsOn(':bmodule')

While Gradle offers an API to resolve this, it will only work if you have no cycle, that is bmodule does not have dependencies on either amodule or cmodule, otherwise you will not be able to find a solution this way.

Another approach would be to leverage proper dependency resolution and declare that you want to share some test classes by having them exposed as test-fixtures for example.

Gradle has three build phases:

• Initialization
• Configuration
• Execution

But the final result of resolving all dependencies appears only when gradle completes all three phases.

The error indicates a string in sourceSets - it is from the phase Configuration. At the start of this phase gradle knows nothing about any configurations in all modules. And gradle learns about the content of each module sequentially module-by-module. Of course when gradle considers the configuration of the amodule for the first time, it doesn't know anything about any configurations in the bmudule.

In the question I want to define compileClasspath and runtimeClasspath in confuguration :amodule:intTest. But there is nothing to stop me to define it in a custom task. Gradle will execute it on the third phase and the final compileClasspath and runtimeClasspath will contain the information from the bmodule:intTest

The result build.gradle of amodule:

sourceSets {
    intTest {
        java {
            srcDir 'src/test-integration/java'
        }
        resources {
            srcDir 'src/test-integration/resources'
        }
    }
}

configurations {
    intTestCompile {
        extendsFrom compile
    }
    intTestRuntime {
        extendsFrom runtime
    }
}

task intTest {
    sourceSets.intTest.compileClasspath += rootProject.project('bmodule').sourceSets.intTest.output
    sourceSets.intTest.runtimeClasspath += rootProject.project('bmodule').sourceSets.intTest.output
}