added test for resample module

tests/test_preprocessing.py

@@ -1,9 +1,11 @@
 import pytest
 import librosa
+import numpy as np
 from src.preprocessing.normalize import normalize_audio
 from src.preprocessing.trim import trim_audio
 from src.preprocessing.classify import classify_audio
 from src.input.file_reader import read_audio
+from src.preprocessing.resample import resample
 
 def test_normalize_audio():
     file_path = "samples/cafe_crowd_talk.aiff"
@@ -26,3 +28,28 @@ def test_classify():
     predicted_class = classify_audio(file_path)
 
     assert predicted_class == expected_class , f"Expected {expected_class}, but got {predicted_class}"
+
+def test_resample():
+    """
+    Test the resample function to ensure it correctly resamples the waveform.
+    """
+
+    # Generate a synthetic sine wave for testing
+    org_samplerate = 22050  # Original sample rate
+    new_samplerate = 16000  # Target sample rate
+    duration = 1.0  # 1 second duration
+    t = np.linspace(0, duration, int(org_samplerate * duration), endpoint=False)
+    waveform = 0.5 * np.sin(2 * np.pi * 440 * t)  # 440 Hz sine wave
+
+    # Perform resampling
+    resampled_waveform, output_samplerate = resample(waveform, org_samplerate, new_samplerate)
+
+    # Assertions
+    assert output_samplerate == new_samplerate, "The output sample rate does not match the target sample rate."
+    assert len(resampled_waveform) == int(new_samplerate * duration), \
+        "The length of the resampled waveform does not match the expected length."
+    assert np.allclose(
+        np.max(resampled_waveform), np.max(waveform), atol=0.1
+    ), "The amplitude of the resampled waveform deviates significantly from the original."
+
+    print("Test passed: resample function works as expected.")