Enable pattern code style

.editorconfig

@@ -164,6 +164,22 @@ dotnet_diagnostic.CA1507.severity=warning # not default, increased severity to e
 # CA2215: Dispose methods should call base class dispose
 dotnet_diagnostic.CA2215.severity=warning # not default, increased severity to ensure it is applied
 
+# IDE0019: Use pattern matching
+# Keep this in sync with csharp_style_pattern_matching_over_as_with_null_check
+dotnet_diagnostic.IDE0019.severity = warning # not default, increased severity to ensure it is applied
+
+# IDE0020:
+# Keep this in sync with csharp_style_pattern_matching_over_is_with_cast_check
+dotnet_diagnostic.IDE0020.severity = warning # not default, increased severity to ensure it is applied
+
+# IDE0078: Use pattern matching
+# Keep this in sync with csharp_style_prefer_pattern_matching
+dotnet_diagnostic.IDE0078.severity = warning # not default, increased severity to ensure it is applied
+
+# IDE0083: Use pattern matching (not operator)
+# Keep this in sync with csharp_style_prefer_not_pattern
+dotnet_diagnostic.IDE0083.severity = warning # not default, increased severity to ensure it is applied
+
 #### C# Coding Conventions ####
 
 # var preferences
@@ -183,11 +199,15 @@ csharp_style_expression_bodied_operators = false:silent
 csharp_style_expression_bodied_properties = true:silent
 
 # Pattern matching preferences
-csharp_style_pattern_matching_over_as_with_null_check = true:suggestion
-csharp_style_pattern_matching_over_is_with_cast_check = true:suggestion
-csharp_style_prefer_not_pattern = true:suggestion
-csharp_style_prefer_pattern_matching = true:silent
-csharp_style_prefer_switch_expression = true:suggestion
+# Keep this in sync with IDE0019
+csharp_style_pattern_matching_over_as_with_null_check = true:warning
+# Keep this in sync with IDE0020 and IDE0038
+csharp_style_pattern_matching_over_is_with_cast_check = true:warning
+# Keep this in sync with IDE0083
+csharp_style_prefer_not_pattern = true:warning
+# Keep this in sync with IDE0078
+csharp_style_prefer_pattern_matching = true:warning
+csharp_style_prefer_switch_expression = true:warning
 
 # Null-checking preferences
 csharp_style_conditional_delegate_call = true:suggestion

src/Microsoft.TestPlatform.AdapterUtilities/ManagedNameUtilities/ManagedNameHelper.Reflection.cs

@@ -389,7 +389,7 @@ private static void NormalizeAndAppendString(StringBuilder b, string name)
             char c = name[i];
             if (NeedsEscaping(c, i))
             {
-                if (c == '\\' || c == '\'')
+                if (c is '\\' or '\'')
                 {
                     // var encoded = Convert.ToString(((uint)c), 16);
                     // b.Append("\\u");
@@ -494,15 +494,11 @@ private static bool NeedsEscaping(char c, int pos)
         }
 
         var category = CharUnicodeInfo.GetUnicodeCategory(c);
-        if (category == UnicodeCategory.NonSpacingMark        // Mn
-            || category == UnicodeCategory.SpacingCombiningMark  // Mc
-            || category == UnicodeCategory.ConnectorPunctuation  // Pc
-            || category == UnicodeCategory.Format)               // Cf
-        {
-            return false;
-        }
-
-        return true;
+        return category
+            is not UnicodeCategory.NonSpacingMark         // Mn
+            and not UnicodeCategory.SpacingCombiningMark  // Mc
+            and not UnicodeCategory.ConnectorPunctuation  // Pc
+            and not UnicodeCategory.Format;               // Cf
     }
 
     private static string GetTypeString(Type type, bool closedType)

src/Microsoft.TestPlatform.AdapterUtilities/TestIdProvider.cs

@@ -145,20 +145,14 @@ public Sha1Implementation()
         /// </returns>
         private static uint F(int t, uint b, uint c, uint d)
         {
-            if (t >= 0 && t <= 19)
+            return t switch
             {
-                return (b & c) | (~b & d);
-            }
-            else if ((t >= 20 && t <= 39) || (t >= 60 && t <= 79))
-            {
-                return b ^ c ^ d;
-            }
-            else
-            {
-                return t >= 40 && t <= 59
-                    ? (b & c) | (b & d) | (c & d)
-                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t));
-            }
+                >= 0 and <= 19 => b & c | ~b & d,
+                >= 20 and <= 39 or >= 60 and <= 79 => b ^ c ^ d,
+                _ => t is >= 40 and <= 59
+                    ? b & c | b & d | c & d
+                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t))
+            };
         }
 
         /// <summary>
@@ -173,22 +167,15 @@ private static uint F(int t, uint b, uint c, uint d)
         /// </returns>
         private static uint K(int t)
         {
-            if (t >= 0 && t <= 19)
-            {
-                return 0x5A827999u;
-            }
-            else if (t >= 20 && t <= 39)
-            {
-                return 0x6ED9EBA1u;
-            }
-            else if (t >= 40 && t <= 59)
+            return t switch
             {
-                return 0x8F1BBCDCu;
-            }
-            else
-            {
-                return t >= 60 && t <= 79 ? 0xCA62C1D6u : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t));
-            }
+                >= 0 and <= 19 => 0x5A827999u,
+                >= 20 and <= 39 => 0x6ED9EBA1u,
+                >= 40 and <= 59 => 0x8F1BBCDCu,
+                _ => t is >= 60 and <= 79
+                    ? 0xCA62C1D6u
+                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t))
+            };
         }
 
         /// <summary>

src/Microsoft.TestPlatform.Client/Execution/TestRunRequest.cs

@@ -189,10 +189,9 @@ public bool WaitForCompletion(int timeout)
             throw new ObjectDisposedException("testRunRequest");
         }
 
-        if (State != TestRunState.InProgress
-            && !(State == TestRunState.Completed
-                 || State == TestRunState.Canceled
-                 || State == TestRunState.Aborted))
+        if (State
+            is not TestRunState.InProgress
+            and not (TestRunState.Completed or TestRunState.Canceled or TestRunState.Aborted))
         {
             // If run is already terminated, then we should not throw an exception.
             throw new InvalidOperationException(ClientResources.WaitForCompletionOperationIsNotAllowedWhenNoTestRunIsActive);

src/Microsoft.TestPlatform.Common/DataCollection/TestPlatformDataCollectionLogger.cs

@@ -127,7 +127,7 @@ private void SendTextMessage(DataCollectionContext context, string text, TestMes
         ValidateArg.NotNull(text, nameof(text));
 
         Debug.Assert(
-            level >= TestMessageLevel.Informational && level <= TestMessageLevel.Error,
+            level is >= TestMessageLevel.Informational and <= TestMessageLevel.Error,
             "Invalid level: " + level);
 
         // Make sure the data collection context is not a derived data collection context.  This

src/Microsoft.TestPlatform.Common/Filtering/FastFilter.cs

@@ -189,7 +189,7 @@ internal void AddCondition(Condition condition)
                 AddProperty(condition.Name, condition.Value);
 
                 // Don't support `Contains`.
-                if (_fastFilterOperation != Operation.Equal && _fastFilterOperation != Operation.NotEqual)
+                if (_fastFilterOperation is not Operation.Equal and not Operation.NotEqual)
                 {
                     _containsValidFilter = false;
                 }

src/Microsoft.TestPlatform.Common/Utilities/FakesUtilities.cs

@@ -172,9 +172,10 @@ private static bool AddFallbackFakesSettings(
 
         // The fallback settings is for the old implementation of fakes 
         // that only supports .Net Framework versions
-        if (framework != FrameworkVersion.Framework35 &&
-            framework != FrameworkVersion.Framework40 &&
-            framework != FrameworkVersion.Framework45)
+        if (framework
+            is not FrameworkVersion.Framework35
+            and not FrameworkVersion.Framework40
+            and not FrameworkVersion.Framework45)
         {
             return false;
         }

src/Microsoft.TestPlatform.CoreUtilities/ValidateArg.cs

@@ -142,7 +142,7 @@ public static void TypeOf<T>([ValidatedNotNull] object arg, string parameterName
     {
         NotNull(arg, parameterName);
 
-        if (!(arg is T))
+        if (arg is not T)
         {
             var message = string.Format(CultureInfo.CurrentCulture, Resources.Error_ArgumentNotTypeOf, typeof(T).FullName);
             throw new ArgumentException(message, parameterName);
@@ -218,7 +218,7 @@ public static void TypeOf<T>([ValidatedNotNull] object arg, string parameterName
     {
         NotNull(arg, parameterName, propertyName);
 
-        if (!(arg is T))
+        if (arg is not T)
         {
             var message = string.Format(CultureInfo.CurrentCulture, Resources.Error_ArgumentPropertyNotTypeOf, propertyName, typeof(T).FullName);
             throw new ArgumentException(message, parameterName);

src/Microsoft.TestPlatform.CrossPlatEngine/Discovery/DiscovererEnumerator.cs

@@ -381,8 +381,7 @@ internal static Dictionary<LazyExtension<ITestDiscoverer, ITestDiscovererCapabil
         {
             var sourcesToCheck = sources;
 
-            if (discoverer.Metadata.AssemblyType == AssemblyType.Native ||
-                discoverer.Metadata.AssemblyType == AssemblyType.Managed)
+            if (discoverer.Metadata.AssemblyType is AssemblyType.Native or AssemblyType.Managed)
             {
                 assemblyTypeToSoucesMap ??= GetAssemblyTypeToSoucesMap(sources, assemblyProperties);
                 sourcesToCheck = assemblyTypeToSoucesMap[AssemblyType.None].Concat(assemblyTypeToSoucesMap[discoverer.Metadata.AssemblyType]);

src/Microsoft.TestPlatform.CrossPlatEngine/EventHandlers/TestRequestHandler.cs

@@ -297,7 +297,7 @@ public void OnMessageReceived(object sender, MessageReceivedEventArgs messageRec
                     else
                     {
                         var flag = Environment.GetEnvironmentVariable("VSTEST_DISABLE_PROTOCOL_3_VERSION_DOWNGRADE");
-                        var flagIsEnabled = flag != null && flag != "0";
+                        var flagIsEnabled = flag is not null and not "0";
                         var dowgradeIsDisabled = flagIsEnabled;
                         _protocolVersion = dowgradeIsDisabled ? negotiatedVersion : 2;
                     }

src/Microsoft.TestPlatform.CrossPlatEngine/Execution/BaseRunTests.cs

@@ -415,7 +415,7 @@ private bool RunTestInternalWithExecutors(IEnumerable<Tuple<Uri, string>> execut
             // host by default.
             // Same goes if all adapters implement the new test executor interface but at
             // least one of them needs the test platform to attach to the default test host.
-            if (!(executor.Value is ITestExecutor2)
+            if (executor.Value is not ITestExecutor2
                 || ShouldAttachDebuggerToTestHost(executor, executorUriExtensionTuple, RunContext))
             {
                 EqtTrace.Verbose("Attaching to default test host.");

src/Microsoft.TestPlatform.CrossPlatEngine/Execution/RunTestsWithSources.cs

@@ -125,7 +125,7 @@ protected override bool ShouldAttachDebuggerToTestHost(
     {
         // If the adapter doesn't implement the new test executor interface we should attach to
         // the default test host by default to preserve old behavior.
-        return !(executor?.Value is ITestExecutor2 convertedExecutor)
+        return executor?.Value is not ITestExecutor2 convertedExecutor
                || convertedExecutor.ShouldAttachToTestHost(
                    _executorUriVsSourceList[executorUriExtensionTuple],
                    runContext);

src/Microsoft.TestPlatform.CrossPlatEngine/Execution/RunTestsWithTests.cs

@@ -83,7 +83,7 @@ protected override bool ShouldAttachDebuggerToTestHost(
     {
         // If the adapter doesn't implement the new test executor interface we should attach to
         // the default test host by default to preserve old behavior.
-        return !(executor?.Value is ITestExecutor2 convertedExecutor)
+        return executor?.Value is not ITestExecutor2 convertedExecutor
                || convertedExecutor.ShouldAttachToTestHost(_executorUriVsTestList[executorUri], runContext);
     }
 

src/Microsoft.TestPlatform.Extensions.BlameDataCollector/ProcDumpDumper.cs

@@ -274,7 +274,7 @@ private bool TryGetProcDumpExecutable(int processId, out string path)
         }
         else
         {
-            filename = _environment.OperatingSystem == PlatformOperatingSystem.Unix || _environment.OperatingSystem == PlatformOperatingSystem.OSX
+            filename = _environment.OperatingSystem is PlatformOperatingSystem.Unix or PlatformOperatingSystem.OSX
                 ? Constants.ProcdumpUnixProcess
                 : throw new NotSupportedException($"Not supported platform {_environment.OperatingSystem}");
         }

src/Microsoft.TestPlatform.Extensions.BlameDataCollector/WindowsHangDumper.cs

@@ -37,7 +37,7 @@ public WindowsHangDumper(Action<string> logWarning)
     public void Dump(int processId, string outputDirectory, DumpTypeOption type)
     {
         var process = Process.GetProcessById(processId);
-        var processTree = process.GetProcessTree().Where(p => p.Process.ProcessName != "conhost" && p.Process.ProcessName != "WerFault").ToList();
+        var processTree = process.GetProcessTree().Where(p => p.Process.ProcessName is not "conhost" and not "WerFault").ToList();
 
         if (processTree.Count > 1)
         {

src/Microsoft.TestPlatform.ObjectModel/Logging/Events/TestRunMessageEventArgs.cs

@@ -28,7 +28,7 @@ public TestRunMessageEventArgs(TestMessageLevel level, string message)
             throw new ArgumentException(CommonResources.CannotBeNullOrEmpty, nameof(message));
         }
 
-        if (level < TestMessageLevel.Informational || level > TestMessageLevel.Error)
+        if (level is < TestMessageLevel.Informational or > TestMessageLevel.Error)
         {
             throw new ArgumentOutOfRangeException(nameof(level));
         }

src/Microsoft.TestPlatform.ObjectModel/Navigation/PortablePdbReader.cs

@@ -95,8 +95,10 @@ public DiaNavigationData GetDiaNavigationData(MethodInfo methodInfo)
     internal static bool IsPortable(Stream stream)
     {
         // First four bytes should be 'BSJB'
+#pragma warning disable IDE0078 // Use pattern matching (may change code meaning)
         var result = (stream.ReadByte() == 'B') && (stream.ReadByte() == 'S') && (stream.ReadByte() == 'J')
                      && (stream.ReadByte() == 'B');
+#pragma warning restore IDE0078 // Use pattern matching (may change code meaning)
         stream.Position = 0;
         return result;
     }

src/Microsoft.TestPlatform.ObjectModel/TestResult.cs

@@ -357,6 +357,6 @@ public static class TestResultProperties
 
     private static bool ValidateOutcome(object value)
     {
-        return (TestOutcome)value <= TestOutcome.NotFound && (TestOutcome)value >= TestOutcome.None;
+        return (TestOutcome)value is <= TestOutcome.NotFound and >= TestOutcome.None;
     }
 }

src/Microsoft.TestPlatform.ObjectModel/Utilities/AssemblyLoadWorker.cs

@@ -307,7 +307,7 @@ private static string GetArchitectureForSource(string imagePath)
 
                     // magic number.32bit or 64bit assembly.
                     UInt16 magic = reader.ReadUInt16();
-                    if (magic != 0x010B && magic != 0x020B)
+                    if (magic is not 0x010B and not 0x020B)
                     {
                         validImage = false;
                     }

src/Microsoft.TestPlatform.ObjectModel/Utilities/Sha1Helper.cs

@@ -67,20 +67,14 @@ internal class Sha1Implementation
         /// </returns>
         private static uint F(int t, uint b, uint c, uint d)
         {
-            if (t >= 0 && t <= 19)
+            return t switch
             {
-                return (b & c) | (~b & d);
-            }
-            else if ((t >= 20 && t <= 39) || (t >= 60 && t <= 79))
-            {
-                return b ^ c ^ d;
-            }
-            else
-            {
-                return t >= 40 && t <= 59
-                    ? (b & c) | (b & d) | (c & d)
-                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t));
-            }
+                >= 0 and <= 19 => b & c | ~b & d,
+                >= 20 and <= 39 or >= 60 and <= 79 => b ^ c ^ d,
+                _ => t is >= 40 and <= 59
+                    ? b & c | b & d | c & d
+                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t))
+            };
         }
 
         /// <summary>
@@ -95,23 +89,15 @@ private static uint F(int t, uint b, uint c, uint d)
         /// </returns>
         private static uint K(int t)
         {
-
-            if (t >= 0 && t <= 19)
+            return t switch
             {
-                return 0x5A827999u;
-            }
-            else if (t >= 20 && t <= 39)
-            {
-                return 0x6ED9EBA1u;
-            }
-            else if (t >= 40 && t <= 59)
-            {
-                return 0x8F1BBCDCu;
-            }
-            else
-            {
-                return t >= 60 && t <= 79 ? 0xCA62C1D6u : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t));
-            }
+                >= 0 and <= 19 => 0x5A827999u,
+                >= 20 and <= 39 => 0x6ED9EBA1u,
+                >= 40 and <= 59 => 0x8F1BBCDCu,
+                _ => t is >= 60 and <= 79
+                    ? 0xCA62C1D6u
+                    : throw new ArgumentException("Argument out of bounds! 0 <= t < 80", nameof(t))
+            };
         }
 
         /// <summary>

src/Microsoft.TestPlatform.PlatformAbstractions/common/System/ProcessHelper.cs

@@ -198,7 +198,7 @@ public int GetProcessId(object process)
     public string GetNativeDllDirectory()
     {
         var osArchitecture = new PlatformEnvironment().Architecture;
-        return osArchitecture == PlatformArchitecture.ARM || osArchitecture == PlatformArchitecture.ARM64
+        return osArchitecture is PlatformArchitecture.ARM or PlatformArchitecture.ARM64
             ? Path.Combine(GetCurrentProcessLocation(), GetCurrentProcessArchitecture().ToString().ToLower(), Arm)
             : Path.Combine(GetCurrentProcessLocation(), GetCurrentProcessArchitecture().ToString().ToLower());
     }

src/Microsoft.TestPlatform.PlatformAbstractions/net451/System/PlatformEnvironment.cs

@@ -35,7 +35,9 @@ public PlatformOperatingSystem OperatingSystem
             // CLR 2.x. See below link for more information:
             // http://www.mono-project.com/docs/faq/technical/#how-to-detect-the-execution-platform
             int p = (int)Environment.OSVersion.Platform;
-            return (p == 4) || (p == 6) || (p == 128) ? PlatformOperatingSystem.Unix : PlatformOperatingSystem.Windows;
+            return p is 4 or 6 or 128
+                ? PlatformOperatingSystem.Unix
+                : PlatformOperatingSystem.Windows;
         }
     }
 

src/Microsoft.TestPlatform.TestHostProvider/Hosting/DotnetTestHostManager.cs

@@ -262,7 +262,7 @@ public virtual TestProcessStartInfo GetTestHostProcessStartInfo(
             && !IsWinOnArm())
         {
             // testhost.exe is 64-bit and has no suffix other versions have architecture suffix.
-            var exeName = _architecture == Architecture.X64 || _architecture == Architecture.Default || _architecture == Architecture.AnyCPU
+            var exeName = _architecture is Architecture.X64 or Architecture.Default or Architecture.AnyCPU
                 ? "testhost.exe"
                 : $"testhost.{_architecture.ToString().ToLowerInvariant()}.exe";
 
@@ -283,7 +283,7 @@ public virtual TestProcessStartInfo GetTestHostProcessStartInfo(
                 {
                     // testhost.dll is present in path {testHostNugetRoot}\lib\netcoreapp2.1\testhost.dll
                     // testhost.(x86).exe is present in location {testHostNugetRoot}\build\netcoreapp2.1\{x86/x64}\{testhost.x86.exe/testhost.exe}
-                    var folderName = _architecture == Architecture.X64 || _architecture == Architecture.Default || _architecture == Architecture.AnyCPU
+                    var folderName = _architecture is Architecture.X64 or Architecture.Default or Architecture.AnyCPU
                         ? Architecture.X64.ToString().ToLowerInvariant()
                         : _architecture.ToString().ToLowerInvariant();