feat(mac,ios,playback,store): initial macos implementation

Packages/AmphlifyKit/Tests/PlaybackTests/SampleRateMatcherTests.swift

@@ -0,0 +1,34 @@
+import Domain
+import Foundation
+@testable import Playback
+import Testing
+
+struct SampleRateMatcherTests {
+    private let device = OutputDeviceInfo(id: 1, name: "Fake", nominalRate: 48000, availableRates: [44100, 48000, 96000])
+    private let flac = AudioFormat(codec: .flac, sampleRate: 44100, bitDepth: 16)
+
+    @Test func settingOffLeavesDeviceAlone() {
+        #expect(SampleRateMatcher(isEnabled: false).targetRate(for: flac, on: device) == nil)
+    }
+
+    @Test func sameRateNeedsNoSwitch() {
+        let format = AudioFormat(codec: .flac, sampleRate: 48000)
+        #expect(SampleRateMatcher(isEnabled: true).targetRate(for: format, on: device) == nil)
+    }
+
+    @Test func unavailableRateIsIgnored() {
+        let format = AudioFormat(codec: .flac, sampleRate: 192_000)
+        #expect(SampleRateMatcher(isEnabled: true).targetRate(for: format, on: device) == nil)
+    }
+
+    @Test func unknownRateOrDeviceIsIgnored() {
+        let matcher = SampleRateMatcher(isEnabled: true)
+        #expect(matcher.targetRate(for: AudioFormat(codec: .mp3), on: device) == nil)
+        #expect(matcher.targetRate(for: nil, on: device) == nil)
+        #expect(matcher.targetRate(for: flac, on: nil) == nil)
+    }
+
+    @Test func availableRateIsChosenExactly() {
+        #expect(SampleRateMatcher(isEnabled: true).targetRate(for: flac, on: device) == 44100)
+    }
+}