feat(test): add LLM test support abstraction for graceful skipping

[venkateshsakamuri-lab]

Summary

This PR introduces a test support abstraction for LLM-dependent tests, allowing them to skip gracefully when LLM credentials are not configured instead of failing with cryptic errors.

Problem

Previously, integration tests that required LLM configuration (like ChatPromptIntegrationTest) would fail with "agent runtime hit an internal execution failure" when LLM credentials weren't set. This made it impossible to get a clean test run without full LLM configuration.

Solution

Added a new com.dbaagent.support test package with three components:

1. @RequiresLlm Annotation

@RequiresLlm(chat = true, embedding = false)
class ChatPromptIntegrationTest extends BaseIntegrationTest {
    // Tests will skip if chat LLM is not configured
}

• Works at class or method level
• Supports independent chat and embedding requirements
• Tests are skipped (not failed) when LLM is not configured

2. LlmAvailabilityCondition

JUnit 5 ExecutionCondition that checks DEEPSQL_CHAT_* and DEEPSQL_EMBEDDING_* environment variables using the same resolution logic as production LlmConfigResolver.

3. LlmTestSupport

Spring component for use within integration tests that need more control:

@Autowired
private LlmTestSupport llmTestSupport;

@Test
void testWithOptionalLlm() {
    if (llmTestSupport.isChatAvailable()) {
        // test with LLM
    } else {
        // fallback behavior
    }
}

Changes

• New files:

  • backend/src/test/java/com/dbaagent/support/RequiresLlm.java
  • backend/src/test/java/com/dbaagent/support/LlmAvailabilityCondition.java
  • backend/src/test/java/com/dbaagent/support/LlmTestSupport.java
  • backend/src/test/java/com/dbaagent/support/LlmAvailabilityConditionTest.java

• Updated files:

  • backend/src/test/java/com/dbaagent/integration/BaseIntegrationTest.java - Added LlmTestSupport integration and convenience methods
  • backend/src/test/java/com/dbaagent/integration/ChatPromptIntegrationTest.java - Added @RequiresLlm annotation

Test Results

Before this change, ChatPromptIntegrationTest had 20+ failures when LLM wasn't configured.

After this change:

Tests run: 23, Failures: 0, Errors: 0, Skipped: 23

All tests skip cleanly with a clear message about the missing configuration.

How to Use

For new tests requiring LLM:

@RequiresLlm  // Requires chat LLM by default
class MyLlmTest extends BaseIntegrationTest {
    @Test
    void myTest() {
        // This test will skip if chat LLM is not configured
    }
}

For tests requiring both chat and embedding:

@RequiresLlm(chat = true, embedding = true)
class MyFullLlmTest { ... }

For programmatic checks:

@Test
void testWithFallback() {
    if (llmTestSupport.isChatAvailable()) {
        // Full test path
    } else {
        // Degraded test path
    }
}