Added tests for exception cases of start method.

Author: KristofferStrube

src/KristofferStrube.Blazor.WebAudio/AudioNodes/AudioBufferSourceNode.cs

@@ -188,8 +188,8 @@ public async Task SetLoopEndAsync(double value)
     /// </summary>
     /// <remarks>
     /// It throws an <see cref="InvalidStateErrorException"/> if it has already been started.<br />
-    /// It throws an <see cref="RangeErrorException"/> if <paramref name="offset"/> is negative.<br />
-    /// It throws an <see cref="RangeErrorException"/> if <paramref name="duration"/> is negative.
+    /// It throws a <see cref="RangeErrorException"/> if <paramref name="offset"/> is negative.<br />
+    /// It throws a <see cref="RangeErrorException"/> if <paramref name="duration"/> is negative.
     /// </remarks>
     /// <param name="when">The when parameter describes at what time (in seconds) the sound should start playing. It is in the same time coordinate system as the AudioContext's currentTime attribute.</param>
     /// <param name="offset">The offset parameter supplies a playhead position where playback will begin. If <c>0</c> is passed in for this value, then playback will start from the beginning of the buffer.</param>

tests/IntegrationTests/AudioNodeTests/AudioBufferSourceNodeTest.cs

@@ -1,5 +1,6 @@
 using FluentAssertions;
 using KristofferStrube.Blazor.DOM;
+using KristofferStrube.Blazor.WebIDL.Exceptions;
 
 namespace IntegrationTests.AudioNodeTests;
 
@@ -341,4 +342,74 @@ public async Task StartAsync_WithOffsetParameter_StartsOffsetInBuffer(double off
         _ = eventListenerTriggered.Should().BeTrue();
         await node.RemoveOnEndedEventListenerAsync(onEndedListener);
     }
+
+    [Test]
+    public async Task StartAsync_ThrowsInvalidStateErrorException_WhenItHasAlreadyBeenStarted()
+    {
+        // Arrange
+        await using AudioContext context = await AudioContext.CreateAsync(JSRuntime);
+
+        await using AudioBuffer buffer = await AudioBuffer.CreateAsync(JSRuntime, new AudioBufferOptions()
+        {
+            SampleRate = 8000,
+            Length = 1
+        });
+        await using AudioBufferSourceNode node = await AudioBufferSourceNode.CreateAsync(JSRuntime, context, new()
+        {
+            Buffer = buffer
+        });
+        await node.StartAsync();
+
+        // Act
+        Func<Task> action = async () => await node.StartAsync();
+
+        // Assert
+        _ = await action.Should().ThrowAsync<InvalidStateErrorException>();
+    }
+
+    [Test]
+    public async Task StartAsync_WithNegativeOffset_ThrowsRangeErrorException()
+    {
+        // Arrange
+        await using AudioContext context = await AudioContext.CreateAsync(JSRuntime);
+
+        await using AudioBuffer buffer = await AudioBuffer.CreateAsync(JSRuntime, new AudioBufferOptions()
+        {
+            SampleRate = 8000,
+            Length = 1
+        });
+        await using AudioBufferSourceNode node = await AudioBufferSourceNode.CreateAsync(JSRuntime, context, new()
+        {
+            Buffer = buffer
+        });
+
+        // Act
+        Func<Task> action = async () => await node.StartAsync(when: 0, offset: -1);
+
+        // Assert
+        _ = await action.Should().ThrowAsync<RangeErrorException>();
+    }
+
+    [Test]
+    public async Task StartAsync_WithNegativeDuration_ThrowsRangeErrorException()
+    {
+        // Arrange
+        await using AudioContext context = await AudioContext.CreateAsync(JSRuntime);
+
+        await using AudioBuffer buffer = await AudioBuffer.CreateAsync(JSRuntime, new AudioBufferOptions()
+        {
+            SampleRate = 8000,
+            Length = 1
+        });
+        await using AudioBufferSourceNode node = await AudioBufferSourceNode.CreateAsync(JSRuntime, context, new()
+        {
+            Buffer = buffer
+        });
+
+        // Act
+        Func<Task> action = async () => await node.StartAsync(when: 0, offset: 0, duration: -1);
+
+        // Assert
+        _ = await action.Should().ThrowAsync<RangeErrorException>();
+    }
 }