Factor common test patterns into reusable utilitiesHEADmain

Refactor duplicated test setup/teardown code into shared fixtures:
- test_math_helpers.h: Float comparison (test_near, test_near_vec3)
- AudioTestFixture: RAII wrapper for AudioEngine lifecycle
- EffectTestFixture: Combined WebGPU + AudioEngine + MainSequence

Migrated 9 test files (3 math, 6 audio) to use fixtures.
Net reduction: 54 LOC (178 insertions, 232 deletions).

All 34 tests passing.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 33 insertions, 36 deletions

diff --git a/src/tests/audio/test_variable_tempo.cc b/src/tests/audio/test_variable_tempo.cc
index bbc9ebf..da056c5 100644
--- a/src/tests/audio/test_variable_tempo.cc
+++ b/src/tests/audio/test_variable_tempo.cc
@@ -6,6 +6,7 @@
 #include "audio/audio_engine.h"
 #include "audio/backend/mock_audio_backend.h"
 #include "audio/tracker.h"
+#include "../common/audio_test_fixture.h"
 #include <assert.h>
 #include <cmath>
 #include <stdio.h>
@@ -13,11 +14,13 @@
 #if !defined(STRIP_ALL)
 
 // Helper: Setup audio engine for testing
-static void setup_audio_test(MockAudioBackend& backend, AudioEngine& engine) {
+static AudioTestFixture*
+setup_audio_test(MockAudioBackend& backend) {
   audio_set_backend(&backend);
-  engine.init();
-  engine.load_music_data(&g_tracker_score, g_tracker_samples,
-                         g_tracker_sample_assets, g_tracker_samples_count);
+  AudioTestFixture* fixture = new AudioTestFixture();
+  fixture->load_music(&g_tracker_score, g_tracker_samples,
+                      g_tracker_sample_assets, g_tracker_samples_count);
+  return fixture;
 }
 
 // Helper: Simulate tempo advancement with fixed steps
@@ -47,14 +50,13 @@ void test_basic_tempo_scaling() {
   printf("Test: Basic tempo scaling (1.0x, 2.0x, 0.5x)...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   // Test 1: Normal tempo (1.0x)
   {
     backend.clear_events();
     float music_time = 0.0f;
-    simulate_tempo(engine, music_time, 1.0f, 1.0f);
+    simulate_tempo(fixture->engine(), music_time, 1.0f, 1.0f);
     printf("  1.0x tempo: music_time = %.3f (expected ~1.0)\n", music_time);
     assert(std::abs(music_time - 1.0f) < 0.01f);
   }
@@ -62,9 +64,9 @@ void test_basic_tempo_scaling() {
   // Test 2: Fast tempo (2.0x)
   {
     backend.clear_events();
-    engine.reset();
+    fixture->engine().reset();
     float music_time = 0.0f;
-    simulate_tempo(engine, music_time, 1.0f, 2.0f);
+    simulate_tempo(fixture->engine(), music_time, 1.0f, 2.0f);
     printf("  2.0x tempo: music_time = %.3f (expected ~2.0)\n", music_time);
     assert(std::abs(music_time - 2.0f) < 0.01f);
   }
@@ -72,14 +74,14 @@ void test_basic_tempo_scaling() {
   // Test 3: Slow tempo (0.5x)
   {
     backend.clear_events();
-    engine.reset();
+    fixture->engine().reset();
     float music_time = 0.0f;
-    simulate_tempo(engine, music_time, 1.0f, 0.5f);
+    simulate_tempo(fixture->engine(), music_time, 1.0f, 0.5f);
     printf("  0.5x tempo: music_time = %.3f (expected ~0.5)\n", music_time);
     assert(std::abs(music_time - 0.5f) < 0.01f);
   }
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ Basic tempo scaling works correctly\n");
 }
 
@@ -87,8 +89,7 @@ void test_2x_speedup_reset_trick() {
   printf("Test: 2x SPEED-UP reset trick...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   float music_time = 0.0f;
   float physical_time = 0.0f;
@@ -97,7 +98,7 @@ void test_2x_speedup_reset_trick() {
   // Phase 1: Accelerate from 1.0x to 2.0x over 5 seconds
   printf("  Phase 1: Accelerating 1.0x → 2.0x\n");
   auto accel_fn = [](float t) { return fminf(1.0f + (t / 5.0f), 2.0f); };
-  simulate_tempo_fn(engine, music_time, physical_time, 5.0f, dt, accel_fn);
+  simulate_tempo_fn(fixture->engine(), music_time, physical_time, 5.0f, dt, accel_fn);
 
   const float tempo_scale = accel_fn(physical_time);
   printf("    After 5s physical: tempo=%.2fx, music_time=%.3f\n", tempo_scale,
@@ -107,14 +108,14 @@ void test_2x_speedup_reset_trick() {
   // Phase 2: RESET - back to 1.0x tempo
   printf("  Phase 2: RESET to 1.0x tempo\n");
   const float music_time_before_reset = music_time;
-  simulate_tempo(engine, music_time, 2.0f, 1.0f, dt);
+  simulate_tempo(fixture->engine(), music_time, 2.0f, 1.0f, dt);
 
   printf("    After reset + 2s: tempo=1.0x, music_time=%.3f\n", music_time);
   const float music_time_delta = music_time - music_time_before_reset;
   printf("    Music time delta: %.3f (expected ~2.0)\n", music_time_delta);
   assert(std::abs(music_time_delta - 2.0f) < 0.1f);
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ 2x speed-up reset trick verified\n");
 }
 
@@ -122,8 +123,7 @@ void test_2x_slowdown_reset_trick() {
   printf("Test: 2x SLOW-DOWN reset trick...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   float music_time = 0.0f;
   float physical_time = 0.0f;
@@ -132,7 +132,7 @@ void test_2x_slowdown_reset_trick() {
   // Phase 1: Decelerate from 1.0x to 0.5x over 5 seconds
   printf("  Phase 1: Decelerating 1.0x → 0.5x\n");
   auto decel_fn = [](float t) { return fmaxf(1.0f - (t / 10.0f), 0.5f); };
-  simulate_tempo_fn(engine, music_time, physical_time, 5.0f, dt, decel_fn);
+  simulate_tempo_fn(fixture->engine(), music_time, physical_time, 5.0f, dt, decel_fn);
 
   const float tempo_scale = decel_fn(physical_time);
   printf("    After 5s physical: tempo=%.2fx, music_time=%.3f\n", tempo_scale,
@@ -142,14 +142,14 @@ void test_2x_slowdown_reset_trick() {
   // Phase 2: RESET - back to 1.0x tempo
   printf("  Phase 2: RESET to 1.0x tempo\n");
   const float music_time_before_reset = music_time;
-  simulate_tempo(engine, music_time, 2.0f, 1.0f, dt);
+  simulate_tempo(fixture->engine(), music_time, 2.0f, 1.0f, dt);
 
   printf("    After reset + 2s: tempo=1.0x, music_time=%.3f\n", music_time);
   const float music_time_delta = music_time - music_time_before_reset;
   printf("    Music time delta: %.3f (expected ~2.0)\n", music_time_delta);
   assert(std::abs(music_time_delta - 2.0f) < 0.1f);
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ 2x slow-down reset trick verified\n");
 }
 
@@ -157,34 +157,33 @@ void test_pattern_density_swap() {
   printf("Test: Pattern density swap at reset points...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   float music_time = 0.0f;
 
   // Phase 1: Sparse pattern at normal tempo
   printf("  Phase 1: Sparse pattern, normal tempo\n");
-  simulate_tempo(engine, music_time, 3.0f, 1.0f);
+  simulate_tempo(fixture->engine(), music_time, 3.0f, 1.0f);
   const size_t sparse_events = backend.get_events().size();
   printf("    Events during sparse phase: %zu\n", sparse_events);
 
   // Phase 2: Accelerate to 2.0x
   printf("  Phase 2: Accelerating to 2.0x\n");
-  simulate_tempo(engine, music_time, 2.0f, 2.0f);
+  simulate_tempo(fixture->engine(), music_time, 2.0f, 2.0f);
   const size_t events_at_2x = backend.get_events().size() - sparse_events;
   printf("    Additional events during 2.0x: %zu\n", events_at_2x);
 
   // Phase 3: Reset to 1.0x
   printf("  Phase 3: Reset to 1.0x (simulating denser pattern)\n");
   const size_t events_before_reset_phase = backend.get_events().size();
-  simulate_tempo(engine, music_time, 2.0f, 1.0f);
+  simulate_tempo(fixture->engine(), music_time, 2.0f, 1.0f);
   const size_t events_after_reset = backend.get_events().size();
 
   printf("    Events during reset phase: %zu\n",
          events_after_reset - events_before_reset_phase);
   assert(backend.get_events().size() > 0);
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ Pattern density swap points verified\n");
 }
 
@@ -192,8 +191,7 @@ void test_continuous_acceleration() {
   printf("Test: Continuous acceleration from 0.5x to 2.0x...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   float music_time = 0.0f;
   float physical_time = 0.0f;
@@ -215,7 +213,7 @@ void test_continuous_acceleration() {
     physical_time += dt;
     const float tempo_scale = accel_fn(physical_time);
     music_time += dt * tempo_scale;
-    engine.update(music_time, dt * tempo_scale);
+    fixture->engine().update(music_time, dt * tempo_scale);
     if (i % 50 == 0) {
       printf("    t=%.1fs: tempo=%.2fx, music_time=%.3f\n", physical_time,
              tempo_scale, music_time);
@@ -232,7 +230,7 @@ void test_continuous_acceleration() {
          music_time);
   assert(std::abs(music_time - expected_music_time) < 0.5f);
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ Continuous acceleration verified\n");
 }
 
@@ -240,8 +238,7 @@ void test_oscillating_tempo() {
   printf("Test: Oscillating tempo (sine wave)...\n");
 
   MockAudioBackend backend;
-  AudioEngine engine;
-  setup_audio_test(backend, engine);
+  AudioTestFixture* fixture = setup_audio_test(backend);
 
   float music_time = 0.0f;
   float physical_time = 0.0f;
@@ -256,7 +253,7 @@ void test_oscillating_tempo() {
     physical_time += dt;
     const float tempo_scale = oscil_fn(physical_time);
     music_time += dt * tempo_scale;
-    engine.update(music_time, dt * tempo_scale);
+    fixture->engine().update(music_time, dt * tempo_scale);
     if (i % 25 == 0) {
       printf("    t=%.2fs: tempo=%.3fx, music_time=%.3f\n", physical_time,
              tempo_scale, music_time);
@@ -267,7 +264,7 @@ void test_oscillating_tempo() {
          physical_time, music_time, physical_time);
   assert(std::abs(music_time - physical_time) < 0.5f);
 
-  engine.shutdown();
+  delete fixture;
   printf("  ✓ Oscillating tempo verified\n");
 }