test(core/browser/platform): 26 extreme RED/GREEN TDD cycles and full regression hardening (3,235 PASS)

tests/Paca.Tests/Core/M3u8ParserByteRangeAndfMp4ExtremeRedTests.cs

@@ -0,0 +1,131 @@
+using System;
+using Paca.Core.Hls;
+using Paca.Core.Models;
+using Xunit;
+
+namespace Paca.Tests.Core;
+
+public class M3u8ParserByteRangeAndfMp4ExtremeRedTests
+{
+    private static readonly Uri Base = new("https://cdn.example.com/stream/playlist.m3u8");
+
+    [Fact]
+    public void M3u8Parser_ByteRange_ExplicitLengthAndOffset_ParsedCorrectly()
+    {
+        var text = @"#EXTM3U
+#EXT-X-TARGETDURATION:10
+#EXT-X-BYTERANGE:1000@500
+segment.ts";
+
+        var playlist = M3u8Parser.Parse(text, Base);
+        Assert.Single(playlist.Segments);
+        var seg = playlist.Segments[0];
+        Assert.Equal(1000, seg.ByteRangeLength);
+        Assert.Equal(500, seg.ByteRangeOffset);
+    }
+
+    [Fact]
+    public void M3u8Parser_ByteRange_SequentialImplicitOffset_AccumulatesCorrectly()
+    {
+        var text = @"#EXTM3U
+#EXT-X-TARGETDURATION:10
+#EXT-X-BYTERANGE:1000@0
+segment.ts
+#EXT-X-BYTERANGE:2000
+segment.ts
+#EXT-X-BYTERANGE:1500
+segment.ts";
+
+        var playlist = M3u8Parser.Parse(text, Base);
+        Assert.Equal(3, playlist.Segments.Count);
+
+        Assert.Equal(1000, playlist.Segments[0].ByteRangeLength);
+        Assert.Equal(0, playlist.Segments[0].ByteRangeOffset);
+
+        Assert.Equal(2000, playlist.Segments[1].ByteRangeLength);
+        Assert.Equal(1000, playlist.Segments[1].ByteRangeOffset);
+
+        Assert.Equal(1500, playlist.Segments[2].ByteRangeLength);
+        Assert.Equal(3000, playlist.Segments[2].ByteRangeOffset);
+    }
+
+    [Fact]
+    public void M3u8Parser_ByteRange_InvalidNegativeOrNonNumeric_IgnoredGracefully()
+    {
+        var text = @"#EXTM3U
+#EXT-X-TARGETDURATION:10
+#EXT-X-BYTERANGE:-500@-100
+segment1.ts
+#EXT-X-BYTERANGE:invalid@nan
+segment2.ts";
+
+        var playlist = M3u8Parser.Parse(text, Base);
+        Assert.Equal(2, playlist.Segments.Count);
+
+        Assert.Null(playlist.Segments[0].ByteRangeLength);
+        Assert.Null(playlist.Segments[0].ByteRangeOffset);
+
+        Assert.Null(playlist.Segments[1].ByteRangeLength);
+        Assert.Null(playlist.Segments[1].ByteRangeOffset);
+    }
+
+    [Fact]
+    public void M3u8Parser_InitSegment_WithByteRange_ParsedCorrectly()
+    {
+        var text = @"#EXTM3U
+#EXT-X-TARGETDURATION:10
+#EXT-X-MAP:URI=""init.mp4"",BYTERANGE=""800@0""
+#EXTINF:6.0,
+segment1.m4s";
+
+        var playlist = M3u8Parser.Parse(text, Base);
+        Assert.NotNull(playlist.InitSegment);
+        Assert.Equal("https://cdn.example.com/stream/init.mp4", playlist.InitSegment.AbsoluteUri);
+        Assert.Equal(800, playlist.InitByteRangeLength);
+        Assert.Equal(0, playlist.InitByteRangeOffset);
+    }
+
+    [Fact]
+    public void M3u8Parser_NullBaseUrl_ReturnsEmptyPlaylistWithoutCrashing()
+    {
+        var text = @"#EXTM3U
+#EXT-X-TARGETDURATION:10
+segment.ts";
+
+        var playlist = M3u8Parser.Parse(text, null!);
+        Assert.NotNull(playlist);
+        Assert.Empty(playlist.Segments);
+    }
+
+    [Fact]
+    public void Variant_NegativeOrMalformedResolution_ClampsToZero()
+    {
+        var v = new Variant(new Uri("https://example.com/v.m3u8"), 1000, "-1920x-1080", "avc1");
+        Assert.Equal(0, v.Width);
+        Assert.Equal(0, v.Height);
+    }
+
+    [Fact]
+    public void Variant_ComplexResolution_ParsesWidthAndHeight()
+    {
+        var v = new Variant(new Uri("https://example.com/v.m3u8"), 1000, "1920x1080@60fps", "avc1");
+        Assert.Equal(1920, v.Width);
+        Assert.Equal(1080, v.Height);
+    }
+
+    [Fact]
+    public void M3u8Parser_MediaSequence_Int64Overflow_DoesNotGoNegative()
+    {
+        var text = @"#EXTM3U
+#EXT-X-MEDIA-SEQUENCE:9223372036854775807
+#EXTINF:6.0,
+seg1.ts
+#EXTINF:6.0,
+seg2.ts";
+
+        var playlist = M3u8Parser.Parse(text, Base);
+        Assert.Equal(2, playlist.Segments.Count);
+        Assert.True(playlist.Segments[0].Sequence >= 0);
+        Assert.True(playlist.Segments[1].Sequence >= 0);
+    }
+}