JacocoReportAggregationPlugin doesn't work with JvmTestSuitePlugin

[Toldry]

Applying JacocoReportAggregationPlugin and JvmTestSuitePlugin in concert does not create the testCodeCoverageReport task.

This is opposed to what is described in the documentation:

Automatic report creation
When the project also applies the jvm-test-suite plugin, the following reporting objects are added for each test suite:

testSuiteCodeCoverageReport — JacocoCoverageReport
Creates a container to parameterize the TestSuiteType value.

Expected Behavior

The testCodeCoverageReport task is created.

Current Behavior

The testCodeCoverageReport task is missing.

Context

I was trying to follow the documentation and encountered this bug which caused some confusion.

Steps to Reproduce

Here is a bug replicator I made:
https://github.com/Toldry/jacoco-aggregator-plugin-bug-replicator

To reproduce the bug :

git clone https://github.com/Toldry/jacoco-aggregator-plugin-bug-replicator
cd jacoco-aggregator-plugin-bug-replicator
./gradlew test

You will see the following output:

> Task :plugin:test

JacocoAggregatorPluginBugReplicatorPluginTest > pluginAddsTestCodeCoverageReport(String) > jacoco.aggregator.plugin.bug.replicator.JacocoAggregatorPluginBugReplicatorPluginTest.pluginAddsTestCodeCoverageReport(String)[2] FAILED
    org.opentest4j.AssertionFailedError at JacocoAggregatorPluginBugReplicatorPluginTest.java:22

Your Environment

macOS 12.5.1
Java SDK 8.0.322-librca

Build scan URL:
I cannot provide a build scan.

[tresat]

This is behaving as designed.

What's going on here is a little subtle: the JvmTestSuitePlugin will create a task to report on each test suite present in the project, but doesn't actually create any test suites itself. It is usually applied along with the JavaPlugin, which is responsible for creating the default suite.

You can see this behavior clearly by changing your test method in the example to:

    void pluginAddsTestCodeCoverageReport(String option) {
        Project project = ProjectBuilder.builder().build();
        project.getExtensions().getExtraProperties().set("option", option);
        project.getPlugins().apply("jacoco.aggregator.plugin.bug.replicator");

        TestingExtension testing = project.getExtensions().findByType(TestingExtension.class);
        if (null != testing) {
            int numSuites = testing.getSuites().size();
            boolean javaPluginApplied = project.getPlugins().hasPlugin("java");
            assertEquals(javaPluginApplied ? 1 : 0, numSuites);
            if (numSuites > 0) {
                assertNotNull(project.getTasks().findByName("testCodeCoverageReport"));
            }
        }
    }

Which then passes. The failure you were originally seeing is because there weren't any test suites created in the project. No suites, no aggregated report tasks.

@nathan-contino - Maybe we can make this part of the docs clearer somehow?

[Toldry]

Thank you for addressing this.

I would appreciate changing the docs to clarify 🙏