Report discovery issues for @Suite classes

[marcphilipp]

Overview

• Report discovery issues for invalid @Suite classes
• Report discovery issue for cyclic suites
• Document and check preconditions
• Prefix discovery issues encountered while resolving @Suite class

Issue: #242

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Definition of Done

• There are no TODOs left in the code
• Method preconditions are checked and documented in the method's Javadoc
• Coding conventions (e.g. for logging) have been followed
• Change is covered by automated tests including corner cases, errors, and exception handling
• Public API has Javadoc and @API annotations
• Change is documented in the User Guide and Release Notes will be done in a later PR

[Copilot]

Pull Request Overview

This PR introduces enhanced reporting for discovery issues related to @suite classes. Key changes include:

• Reporting discovery issues for invalid suite classes and cyclic suite configurations.
• Adding precondition checks and message prefixing for discovery issues.
• Updating test cases and internal helper classes to support the new discovery issue reporting mechanism.

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
platform-tests/src/test/java/org/junit/platform/suite/engine/testcases/ErroneousTestCase.java	Added test case with non-static lifecycle method to simulate erroneous behavior.
platform-tests/src/test/java/org/junit/platform/suite/engine/testsuites/ErroneousTestSuite.java	Introduced a suite that selects the erroneous test case.
platform-tests/src/test/java/org/junit/platform/suite/engine/testsuites/SuiteWithErroneousTestSuite.java	Provided a suite that includes the erroneous test suite.
platform-tests/src/test/java/org/junit/platform/engine/DiscoveryIssueTests.java	Added tests for the DiscoveryIssue.withMessage functionality.
junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/IsSuiteClass.java	Refactored suite class eligibility checks to use combined conditions reporting issues.
platform-tests/src/test/java/org/junit/platform/suite/engine/SuiteEngineTests.java	Updated suite engine tests to check for proper reporting of discovery issues.
junit-platform-engine/src/main/java/org/junit/platform/engine/DiscoveryIssue.java	Extended the DiscoveryIssue API with a new withMessage method for message modification.
junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/SuiteTestDescriptor.java	Introduced a DiscoveryIssueForwardingListener and adjusted constructor signatures for enhanced reporting.
junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/DiscoverySelectorResolver.java	Modified selector resolution to inject a discovery listener and issue reporter.
junit-platform-suite-commons/src/main/java/org/junit/platform/suite/commons/SuiteLauncherDiscoveryRequestBuilder.java	Added a listener method to the discovery request builder.
junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/ClassSelectorResolver.java	Updated to use the discovery listener and issue reporter when handling cycles.
platform-tests/src/test/java/org/junit/platform/suite/engine/SuiteTestDescriptorTests.java	Adjusted test construction to match updated production code requirements.
junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/IsPotentialTestContainer.java	Removed unused code in favor of updated suite class checks.

Comments suppressed due to low confidence (3)

platform-tests/src/test/java/org/junit/platform/suite/engine/SuiteEngineTests.java:142

• [nitpick] The expected error message in this test is tightly coupled to its formatting. Consider refactoring the error message formatting into a shared constant or helper method to ensure consistency with the discovery issue reporter and reduce brittleness in the tests.

var message = "@Suite class '%s' must not be private.".formatted(PrivateSuite.class.getName());

junit-platform-suite-engine/src/main/java/org/junit/platform/suite/engine/ClassSelectorResolver.java:111

• [nitpick] To improve maintainability, consider defining a constant for the cycle detection message format. This ensures consistent reporting of cycle issues across the codebase and simplifies future updates if the message needs to change.

if (containsCycle(id)) {

platform-tests/src/test/java/org/junit/platform/suite/engine/SuiteTestDescriptorTests.java:55

• [nitpick] Ensure that the mock EngineDiscoveryListener provided in this test sufficiently simulates realistic listener behavior. Additionally, consider adding tests that cover listener-related logic to match production expectations.

outputDirectoryProvider, mock(), discoveryIssueReporter);

[marcphilipp]

@mpkorstanje Do you have time to take a look at this PR?

[marcphilipp]

@mpkorstanje Thanks for your review!