Bug Report

Current Behavior

The DefaultPathProcessorTest#testVanityUrl and DefaultPathProcessorTest#testVanityConfig methods exhibit flaky behavior when execution order is non-deterministic (e.g., when using NonDex for testing). The tests fail intermittently with different error patterns:

testVanityUrl failures:
org.apache.sling.testing.mock.osgi.ReferenceViolationException: Unable to inject mandatory reference 'externalizer' (com.day.cq.commons.Externalizer) for class com.adobe.cq.wcm.core.components.internal.link.DefaultPathProcessor : no matching services were found.

testVanityConfig failures:
org.opentest4j.AssertionFailedError: expected: </content/site1/en.html> but was: </links/site1/en.html>
org.opentest4j.AssertionFailedError: expected: https://example.org/links/site1/en.html but was: https://example.org/content/links/site1/en.html

Steps to reproduce:

1. Run NonDex on the test: mvn edu.illinois:nondex-maven-plugin:2.1.7:nondex -Dtest=DefaultPathProcessorTest#testVanityUrl
2. Observe intermittent failures across different seeds (e.g., fails on seeds 933178, 974622 but passes on 1016066)

Expected behavior/code

Tests should pass consistently regardless of execution order or service registration timing. The tests should be deterministic and not depend on implementation-specific ordering of:

• OSGi service registration and dependency injection
• Resource resolver path mapping behavior

Environment

• AEM Core Components version: 2.30.3-SNAPSHOT
• Test framework: JUnit 5 with AEM Mocks
• Build tool: Maven with NonDex plugin 2.1.7
• JRE version: OpenJDK 64-Bit Server VM

Possible Solution

For testVanityUrl:

// Ensure Externalizer service is available before registering DefaultPathProcessor
Externalizer externalizer = context.getService(Externalizer.class);
if (externalizer == null) {
    // Fallback: register a mock externalizer if not already present
    externalizer = mock(Externalizer.class);
    when(externalizer.publishLink(any(ResourceResolver.class), anyString()))
        .thenAnswer(invocation -> "https://example.org" + invocation.getArgument(1, String.class));
    context.registerService(Externalizer.class, externalizer);
}

For testVanityConfig:

• Replaced hardcoded path assertions with controlled mock ResourceResolver instances
• Eliminated dependency on non-deterministic path mapping behavior
• Used explicit mocking to ensure predictable test outcomes

Additional context / Screenshots

This issue highlights the importance of:

1. Deterministic test design - Tests should not rely on service registration order
2. Proper dependency setup - Explicitly ensure required services are available before component instantiation
3. NonDex integration - Regular flaky test detection in CI/CD pipelines

The flaky behavior would cause intermittent CI failures and reduce confidence in the test suite, potentially masking real regressions.