test: use static random seed in tests

this prevents the code coverage from varying depending on how
well the random data compresses

test/ICSharpCode.SharpZipLib.Tests/BZip2/Bzip2Tests.cs

@@ -12,6 +12,9 @@ namespace ICSharpCode.SharpZipLib.Tests.BZip2
 	[TestFixture]
 	public class BZip2Suite
 	{
+		// Use the same random seed to guarantee all the code paths are followed
+		const int RandomSeed = 4;
+
 		/// <summary>
 		/// Basic compress/decompress test BZip2
 		/// </summary>
@@ -23,7 +26,7 @@ public void BasicRoundTrip()
 			var outStream = new BZip2OutputStream(ms);
 
 			byte[] buf = new byte[10000];
-			var rnd = new Random();
+			var rnd = new Random(RandomSeed);
 			rnd.NextBytes(buf);
 
 			outStream.Write(buf, 0, buf.Length);

test/ICSharpCode.SharpZipLib.Tests/Base/InflaterDeflaterTests.cs

@@ -16,6 +16,9 @@ namespace ICSharpCode.SharpZipLib.Tests.Base
 	[TestFixture]
 	public class InflaterDeflaterTestSuite
 	{
+		// Use the same random seed to guarantee all the code paths are followed
+		const int RandomSeed = 5;
+
 		private void Inflate(MemoryStream ms, byte[] original, int level, bool zlib)
 		{
 			byte[] buf2 = new byte[original.Length];
@@ -60,7 +63,7 @@ private MemoryStream Deflate(byte[] data, int level, bool zlib)
 		private static byte[] GetRandomTestData(int size)
 		{
 			byte[] buffer = new byte[size];
-			var rnd = new Random();
+			var rnd = new Random(RandomSeed);
 			rnd.NextBytes(buffer);
 
 			return buffer;
@@ -184,7 +187,7 @@ public async Task InflateDeflateZlibAsync([Range(0, 9)] int level)
 		private int runLevel;
 		private bool runZlib;
 		private long runCount;
-		private readonly Random runRandom = new Random(5);
+		private readonly Random runRandom = new Random(RandomSeed);
 
 		private void DeflateAndInflate(byte[] buffer)
 		{