Use better temp directory cleanup in tests

Closes dotnet#6233

src/Compilers/CSharp/Test/Syntax/Parsing/ParserRegressionTests.cs

@@ -1,11 +1,9 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using System.IO;
 using Microsoft.CodeAnalysis.CSharp.Test.Utilities;
-using Microsoft.CodeAnalysis.Text;
 using Roslyn.Test.Utilities;
+using Roslyn.Test.Utilities.Syntax;
 using Xunit;
-using System.Text;
 
 namespace Microsoft.CodeAnalysis.CSharp.UnitTests.Parsing
 {
@@ -80,27 +78,10 @@ public void c024928()
         }
 
         [WorkItem(2771, "https://github.com/dotnet/roslyn/issues/2771")]
-        [Fact(Skip = "This test continues to be flaky, even in this form, due to variations in the amount of memory available when it is run")]
+        [ConditionalFact(typeof(IsRelease))]
         public void TestBinary()
         {
-            // Apparently this fixed seed exposed a bug at some point
-            var random = new System.Random(12345);
-            // 40 million "character"s
-            const int n = 40 * 1000 * 1000;
-            var str = new string(' ', n);
-
-            unsafe
-            {
-                fixed(char* chars = str)
-                {
-                    for(int i = 0; i < n; i++)
-                    {
-                        chars[i] = (char)random.Next(char.MaxValue);
-                    }
-                }
-            }
-
-            var tree = CSharpSyntaxTree.ParseText(str);
+            CSharpSyntaxTree.ParseText(new RandomizedSourceText());
         }
     }
 }

src/Compilers/VisualBasic/Test/Syntax/BasicCompilerSyntaxTest.vbproj

@@ -96,7 +96,7 @@
     <Compile Include="IncrementalParser\SyntaxDifferences.vb" />
     <Compile Include="LocationTests.vb" />
     <Compile Include="Parser\DeclarationTests.vb" />
-    <Compile Include="Parser\FuzzTesting.vb" />
+    <Compile Include="Parser\ParserRegressionTests.vb" />
     <Compile Include="Parser\InterpolatedStringParsingTests.vb" />
     <Compile Include="Parser\ParseAsyncTests.vb" />
     <Compile Include="Parser\ParseAttributes.vb" />

src/Compilers/VisualBasic/Test/Syntax/Parser/FuzzTesting.vb → src/Compilers/VisualBasic/Test/Syntax/Parser/ParserRegressionTests.vb

@@ -4,8 +4,9 @@ Imports System.IO
 Imports Microsoft.CodeAnalysis
 Imports Microsoft.CodeAnalysis.Text
 Imports Roslyn.Test.Utilities
+Imports Roslyn.Test.Utilities.Syntax
 
-Public Class FuzzTesting : Inherits BasicTestBase
+Public Class ParserRegressionTests : Inherits BasicTestBase
 
     <WorkItem(540022, "DevDiv")>
     <Fact>
@@ -918,20 +919,9 @@ End Enum
     End Sub
 
     <WorkItem(2867, "https://github.com/dotnet/roslyn/issues/2867")>
-    <Fact(Skip:="https://github.com/dotnet/roslyn/issues/7159")>
+    <ConditionalFact(GetType(IsRelease))>
     Public Sub TestBinary()
-        ' use a fixed seed so the test Is reproducible
-        Dim random = New System.Random(12345)
-        Const n As Integer = 40 * 1000 * 1000 ' 40 million "character"s
-        Dim builder = New System.Text.StringBuilder(n + 10)
-        For i As Integer = 0 To n - 1
-            builder.Append(ChrW(random.Next(&HFFFF)))
-        Next
-
-        Dim source = builder.ToString()
-        Dim tree = VisualBasicSyntaxTree.ParseText(source)
-
-        Assert.Equal(source, tree.ToString())
+        Dim tree = VisualBasicSyntaxTree.ParseText(New RandomizedSourceText())
         Assert.Equal(Syntax.InternalSyntax.Scanner.BadTokenCountLimit, tree.GetDiagnostics().Where(Function(d) d.Code = ERRID.ERR_IllegalChar).Count())
     End Sub
 

src/Test/Utilities/Shared/Assert/ConditionalFactAttribute.cs

@@ -49,4 +49,15 @@ public class IsEnglishLocal : ExecutionCondition
 
         public override string SkipReason => "Current culture is not en-US";
     }
+
+    public class IsRelease : ExecutionCondition
+    {
+#if DEBUG
+        public override bool ShouldSkip => true;
+#else
+        public override bool ShouldSkip => false;
+#endif
+
+        public override string SkipReason => "Not in release mode.";
+    }
 }

src/Test/Utilities/Shared/Syntax/SourceUtilities.cs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+using Microsoft.CodeAnalysis.Text;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Roslyn.Test.Utilities.Syntax
+{
+    internal sealed class RandomizedSourceText: SourceText
+    {
+        private char[] buffer = new char[2048];
+
+        public RandomizedSourceText()
+        {
+            var random = new Random(12345);
+            for (var i = 0; i < buffer.Length; i++)
+            {
+                buffer[i] = (char)random.Next();
+            }
+        }
+
+        public override char this[int position] => buffer[position % buffer.Length];
+
+        public override Encoding Encoding => Encoding.UTF8;
+
+        public override int Length
+        {
+            get
+            {
+                return 40 * 1000 * 1000;
+            }
+        }
+
+        public override void CopyTo(int sourceIndex, char[] destination, int destinationIndex, int count)
+        {
+            for (var i = 0; i < count; i++)
+            {
+                destination[destinationIndex + i] = this[sourceIndex + i];
+            }
+        }
+    }
+}

src/Test/Utilities/Shared/TestUtilities.projitems

@@ -58,6 +58,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Pdb\MockSymWriter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Pdb\PdbTestUtilities.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Pdb\PdbValidation.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Syntax\SourceUtilities.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)TempFiles\DisposableDirectory.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)TempFiles\DisposableFile.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)TempFiles\TempDirectory.cs" />