tests: add piaudio unit tests

piaudio/decode_test.go

@@ -0,0 +1,76 @@
+// Copyright 2025 Jacek Olszak
+// This code is licensed under MIT license (see LICENSE for details)
+
+package piaudio_test
+
+import (
+	_ "embed"
+	"github.com/elgopher/pi/piaudio"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestDecodeRaw(t *testing.T) {
+	t.Run("should decode raw sample", func(t *testing.T) {
+		raw := []byte{0, 1, 255}
+		sample := piaudio.DecodeRaw(raw, 22050)
+
+		assert.Equal(t, []int8{0, 1, -1}, sample.Data())
+		assert.Equal(t, uint16(22050), sample.SampleRate())
+	})
+}
+
+var (
+	//go:embed internal/test/valid.wav
+	validWAV []byte
+	//go:embed internal/test/invalid_16bit.wav
+	invalid16bitWAV []byte
+	//go:embed internal/test/invalid_stereo.wav
+	invalidStereoWAV []byte
+	//go:embed internal/test/invalid-sample-rate.wav
+	invalidSampleRateWAV []byte
+	//go:embed internal/test/invalid-not-pcm.wav
+	invalidNotPCM []byte
+)
+
+func TestDecodeWavOrErr(t *testing.T) {
+	t.Run("should decode valid wav file", func(t *testing.T) {
+		sample, err := piaudio.DecodeWavOrErr(validWAV)
+		require.NoError(t, err)
+		assert.Equal(t, []int8{0, 90, 127, 90, 0, -91, -128, -91}, sample.Data())
+		assert.Equal(t, uint16(8363), sample.SampleRate())
+	})
+
+	t.Run("should return error when wav is invalid", func(t *testing.T) {
+		tests := map[string]struct {
+			file        []byte
+			expectedErr string
+		}{
+			"16-bit": {
+				file:        invalid16bitWAV,
+				expectedErr: "only 8-bit PCM supported, got 16 bits",
+			},
+			"stereo": {
+				file:        invalidStereoWAV,
+				expectedErr: "only mono supported, got 2 channels",
+			},
+			"88200 sample rate": {
+				file:        invalidSampleRateWAV,
+				expectedErr: "sample rate is too high. Max 48kHz supported, got 88200",
+			},
+			"not PCM": {
+				file:        invalidNotPCM,
+				expectedErr: "only PCM supported",
+			},
+		}
+
+		for testName, testCase := range tests {
+			t.Run(testName, func(t *testing.T) {
+				sample, err := piaudio.DecodeWavOrErr(testCase.file)
+				assert.Nil(t, sample)
+				assert.ErrorContains(t, err, testCase.expectedErr)
+			})
+		}
+	})
+}