Function FL_TEST_FILE

tests/fl/audio/adversarial.cpp:25–602

#include "fl/math/math.h"

FL_TEST_FILE(FL_FILEPATH) {

using namespace fl;
using fl::audio::test::makeSample;
using fl::audio::test::makeSilence;
using fl::audio::test::makeDC;
using fl::audio::test::makeMaxAmplitude;

namespace {

static audio::Sample makeSample_Adversarial(float freq, fl::u32 timestamp, float amplitude = 16000.0f) {
    return makeSample(freq, timestamp, amplitude);
}

// Safe NaN check that doesn't rely on isnan
static bool isNaN(float x) {
    return !(x == x);
}

} // anonymous namespace

// F1: audio::fft::FFT Edge Cases

FL_TEST_CASE("Adversarial - audio::fft::FFT with DC-only input produces no spectral peaks") {
    audio::fft::FFT fft;
    fl::vector<fl::i16> dcSignal(512, 10000);  // Pure DC
    audio::fft::Bins bins(16);
    fft.run(dcSignal, &bins);

    // DC should not produce significant energy in frequency bins.
    // With fmin=90 Hz, the lowest CQ bin is closer to DC than with the old
    // fmin=174.6 Hz, so some leakage is expected. The energy should still
    // be modest compared to an in-band sine wave (~30000+ total energy).
    float totalEnergy = 0.0f;
    for (fl::size i = 0; i < bins.raw().size(); ++i) {
        totalEnergy += bins.raw()[i];
    }
    FL_CHECK_LT(totalEnergy, 5000.0f);
}

FL_TEST_CASE("Adversarial - audio::fft::FFT with alternating max samples") {
    audio::fft::FFT fft;
    fl::vector<fl::i16> alternating;
    alternating.reserve(512);
    for (int i = 0; i < 512; ++i) {
        alternating.push_back((i % 2 == 0) ? 32767 : -32768);
    }
    audio::fft::Bins bins(16);
    fft.run(alternating, &bins);

    // Should not crash, bins should have values
    FL_CHECK_GT(bins.raw().size(), 0u);

    // Alternating +-max is essentially Nyquist frequency
    // Energy should be concentrated in the highest bins (if within CQ range)
    // At minimum, it should not produce NaN or Inf
    for (fl::size i = 0; i < bins.raw().size(); ++i) {
        FL_CHECK_FALSE(isNaN(bins.raw()[i]));