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Test failure analysis

Documentation for test_failure_analysis from the Foundation repository.

Test Failure Analysis Report

Executive Summary

Analysis of 18 failing tests reveals 3 distinct architectural failure patterns affecting Signal/Telemetry integration, MABEAM coordination functions, and test infrastructure mismatches. These failures indicate deeper architectural boundary issues rather than simple implementation bugs.

Test Failure Categories

1. Signal/Telemetry Integration Failures (7 tests)

Root Cause: Jido.Signal.Bus integration not properly connected to Foundation telemetry system

Failed Tests:

  • JidoFoundation.SignalIntegrationTest: emits signals through Foundation telemetry
  • JidoFoundation.SignalIntegrationTest: handles signal emission failures gracefully
  • JidoFoundation.SignalRoutingTest: All 5 routing tests

Specific Issues:

  1. Missing Signal Bus: Jido.Signal.Bus.publish/2 calls return {:error, :not_found}
  2. Telemetry Event Not Emitted: Expected [:jido, :signal, :emitted] events never arrive
  3. Signal Routing Not Working: Handlers not receiving routed signals
  4. Bridge Integration Gap: emit_signal/3 function calls Jido.Signal.Bus but bus is not started

Error Pattern:

# Expected
assert_receive {:telemetry, [:jido, :signal, :emitted], measurements, metadata}

# Actual
# The process mailbox is empty.

# Also seeing
assert result == :ok
left:  {:error, :not_found}  # Jido.Signal.Bus not found

2. MABEAM Coordination CaseClauseErrors (11 tests)

Root Cause: Discovery mock return format mismatch - tests expect bare lists but implementation expects {:ok, agents} tuples

Failed Tests: All tests in MABEAM.CoordinationTest

  • coordinate_load_balancing (3 tests)
  • coordinate_capable_agents (2 tests)
  • coordinate_resource_allocation (2 tests)
  • create_capability_barrier (2 tests)
  • error handling (2 tests)

Specific Issues:

  1. Mock Return Format Mismatch:

    # Test mocks return bare list
:meck.expect(MABEAM.Discovery, :find_capable_and_healthy, fn :inference, _impl ->
  [{"agent1", :pid1, %{...}}]  # WRONG - should be {:ok, [...]}
end)

# Implementation expects tuple
case MABEAM.Discovery.find_capable_and_healthy(capability, impl) do
  {:ok, []} -> ...  # CaseClauseError here

  2. Pattern Matching Failures: All coordination functions fail on the first case statement

  3. Inconsistent Test Architecture: Test mocks don’t match actual Discovery module interface

Error Pattern:

** (CaseClauseError) no case clause matching: [{"low_load", :pid1, %{...}}, ...]
# At lib/mabeam/coordination.ex:176 and similar locations

Root Cause Analysis

Architectural Issues (High Priority)

1. Signal Bus Lifecycle Management

  • Issue: Jido.Signal.Bus is not started as part of Foundation supervision tree
  • Impact: All signal emission and routing fails silently
  • Scope: Affects entire Jido-Foundation signal integration
  • Fix Required: Add signal bus to Foundation Application or create startup mechanism

2. Protocol Boundary Inconsistency

  • Issue: MABEAM.Discovery interface changed but test mocks not updated
  • Impact: All multi-agent coordination functions fail
  • Scope: Breaks entire MABEAM coordination layer
  • Fix Required: Update all test mocks to match {:ok, results} interface

3. Test Infrastructure Mismatch

  • Issue: Test doubles don’t reflect actual service interfaces
  • Impact: Tests pass false positives, hide integration issues
  • Scope: Affects test reliability across modules
  • Fix Required: Align test mocks with actual service contracts

Implementation Issues (Medium Priority)

1. Signal Router Not Registered

  • Issue: Signal routing handlers not properly attached to telemetry
  • Impact: Signal subscriptions and routing don’t work
  • Fix Required: Ensure router registration during test setup

2. Agent Registry Lifecycle

  • Issue: Registry state not properly isolated between tests
  • Impact: Agent lookups may find stale data
  • Fix Required: Improve test cleanup and isolation

Transcendent Issues (Affect Multiple Systems)

1. Service Discovery and Lifecycle Management

Problem: Inconsistent patterns for service startup, registration, and cleanup across Foundation, MABEAM, and Jido integration layers.

Evidence:

  • Signal bus not started but referenced
  • Agent registry cleanup issues
  • Mock expectations don’t match service contracts
  • Warning: “No coordination implementation configured”

Impact: Creates brittleness across all integration points

2. Protocol Evolution Without Test Evolution

Problem: Service interfaces evolved (Discovery returning {:ok, results}) but test infrastructure wasn’t updated in lockstep.

Evidence:

  • All MABEAM coordination tests use old mock format
  • CaseClauseError pattern indicates interface mismatch
  • Test passes don’t validate actual integration behavior

Impact: Hidden regressions, false confidence in test suite

3. Event System Integration Gaps

Problem: Foundation telemetry, Jido signals, and BEAM message passing not properly integrated.

Evidence:

  • Telemetry events not emitted despite code paths executing
  • Signal bus publish failures
  • Router handlers not receiving events
  • Cross-system event propagation broken

Impact: Observability and inter-service communication failures

CRITICAL (Fix First)

  1. Fix Discovery Mock Format - Update all test mocks to return {:ok, agents}
  2. Start Signal Bus - Add to Foundation supervision or test setup
  3. Validate Service Contracts - Ensure test doubles match actual interfaces

HIGH

  1. Signal Router Registration - Fix telemetry handler attachment
  2. Test Isolation - Improve registry cleanup between tests
  3. Event Integration - Connect Jido signals to Foundation telemetry properly

MEDIUM

  1. Service Lifecycle Documentation - Document startup dependencies
  2. Protocol Versioning - Add interface stability guarantees
  3. Integration Test Strategy - Add end-to-end integration validation

Architectural Recommendations

1. Service Contract Testing

Implement contract tests that validate test doubles match actual service interfaces to prevent future interface drift.

2. Supervision Tree Audit

Review and document all service dependencies and startup order requirements across Foundation, MABEAM, and Jido layers.

3. Event System Unification

Design consistent event propagation patterns across all systems with clear integration points and failure modes.

4. Test Architecture Refactor

Separate unit tests (with mocks) from integration tests (with real services) to catch interface mismatches earlier.

Total Failing Tests: 18
Root Cause Categories: 3
Transcendent Issues: 3
Estimated Fix Time: 2-4 hours for critical path, 1-2 days for full resolution