Attach C# 9 features to LanguageVersion.CSharp9 (#46645)

src/Analyzers/CSharp/Tests/AddAccessibilityModifiers/AddAccessibilityModifiersTests.cs

@@ -187,7 +187,7 @@ public sealed class IsExternalInit
             {
                 TestCode = source,
                 FixedCode = fixedSource,
-                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.Preview,
+                LanguageVersion = CodeAnalysis.CSharp.LanguageVersion.CSharp9,
             };
 
             await test.RunAsync();

src/Analyzers/CSharp/Tests/ConvertSwitchStatementToExpression/ConvertSwitchStatementToExpressionTests.cs

@@ -1917,7 +1917,7 @@ public async Task TopLevelStatement()
             {
                 TestCode = source,
                 FixedCode = fixedSource,
-                LanguageVersion = LanguageVersion.Preview,
+                LanguageVersion = LanguageVersion.CSharp9,
             };
 
             test.ExpectedDiagnostics.Add(
@@ -1962,7 +1962,7 @@ public async Task TopLevelStatement_FollowedWithThrow()
             {
                 TestCode = source,
                 FixedCode = fixedSource,
-                LanguageVersion = LanguageVersion.Preview,
+                LanguageVersion = LanguageVersion.CSharp9,
             };
 
             test.ExpectedDiagnostics.Add(

src/Analyzers/CSharp/Tests/RemoveUnusedParametersAndValues/RemoveUnusedValueAssignmentTests.cs

@@ -2420,7 +2420,37 @@ void M(object p)
                 break;
         };
     }
-}", options: PreferDiscard);
+}", options: PreferDiscard, parseOptions: new CSharpParseOptions(LanguageVersion.CSharp8));
+        }
+
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnusedValues)]
+        public async Task DeclarationPatternInSwitchCase_WithOnlyWriteReference_PreferDiscard_CSharp9()
+        {
+            await TestInRegularAndScriptAsync(
+@"class C
+{
+    void M(object p)
+    {
+        switch (p)
+        {
+            case int [|x|]:
+                x = 1;
+                break;
+        };
+    }
+}",
+@"class C
+{
+    void M(object p)
+    {
+        switch (p)
+        {
+            case int:
+                int x = 1;
+                break;
+        };
+    }
+}", options: PreferDiscard, parseOptions: new CSharpParseOptions(LanguageVersion.CSharp9));
         }
 
         [Theory, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnusedValues)]
@@ -4918,7 +4948,7 @@ void M(object p)
                 break;
         }}
     }}
-}}", optionName);
+}}", optionName, parseOptions: new CSharpParseOptions(LanguageVersion.CSharp8));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnusedValues)]
@@ -7684,7 +7714,7 @@ void M(object p)
                 break;
         };
     }
-}", options: PreferDiscard);
+}", options: PreferDiscard, parseOptions: new CSharpParseOptions(LanguageVersion.CSharp8));
         }
 
         [WorkItem(32856, "https://github.com/dotnet/roslyn/issues/33312")]
@@ -8131,7 +8161,7 @@ void M()
         using var [|x|] = new C();
     }
 }", options: PreferDiscard,
-    parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Preview));
+    parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp9));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnusedValues)]
@@ -8153,7 +8183,7 @@ void M()
         using var [|x|] = new C() { P = 1 };
     }
 }", options: PreferDiscard,
-    parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Preview));
+    parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp9));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnusedValues)]

src/Analyzers/CSharp/Tests/UsePatternMatching/CSharpAsAndNullCheckTests.cs

@@ -1055,7 +1055,7 @@ string M(object o)
         if (!(o is string x)) return null;
         return x;
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1090,7 +1090,7 @@ string M(object o, bool b)
             return x;
         }
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1330,7 +1330,7 @@ void M(object e)
     {
         for (; !(!(e is C c));) { }
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1357,7 +1357,7 @@ void M(object e)
             M(c);
         }
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1406,7 +1406,7 @@ void M(object e, bool b)
             M(c);
         }
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1434,7 +1434,7 @@ void M(object e)
             M(c);
         }
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1489,7 +1489,7 @@ void M(object e)
     {
         C F() => !(e is C c) ? null : c;
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
@@ -1525,7 +1525,7 @@ void M(object e)
     {
         System.Func<C> f = () => !(e is C c) ? null : c;
     }
-}");
+}", parameters: new TestParameters(CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8)));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]

src/Analyzers/CSharp/Tests/UsePatternMatching/CSharpAsAndNullCheckTests_FixAllTests.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Test.Utilities;
 using Roslyn.Test.Utilities;
 using Xunit;
@@ -61,7 +62,60 @@ int M()
 
         return o is string e ? 1 : 0;
     }
-}");
+}", parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp8));
+        }
+
+        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/46821"), Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]
+        public async Task FixAllInDocument1_CSharp9()
+        {
+            await TestInRegularAndScriptAsync(
+@"class C
+{
+    int M()
+    {
+        string a;
+        {|FixAllInDocument:var|} x = o as string;
+        if (x != null)
+        {
+        }
+
+        var y = o as string;
+        if (y != null)
+        {
+        }
+
+        if ((a = o as string) == null)
+        {
+        }
+
+        var c = o as string;
+        var d = c != null ? 1 : 0;
+
+        var e = o as string;
+        return e != null ? 1 : 0;
+    }
+}",
+@"class C
+{
+    int M()
+    {
+        if (o is string x)
+        {
+        }
+
+        if (o is string y)
+        {
+        }
+
+        if (o is not string a)
+        {
+        }
+
+        var d = o is string c ? 1 : 0;
+
+        return o is string e ? 1 : 0;
+    }
+}", parseOptions: CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp9));
         }
 
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsInlineTypeCheck)]

src/Compilers/CSharp/Portable/Errors/MessageID.cs

@@ -319,7 +319,7 @@ internal static LanguageVersion RequiredVersion(this MessageID feature)
             // Checks are in the LanguageParser unless otherwise noted.
             switch (feature)
             {
-                // C# preview features.
+                // C# 9.0 features.
                 case MessageID.IDS_FeatureLambdaDiscardParameters: // semantic check
                 case MessageID.IDS_FeatureFunctionPointers:
                 case MessageID.IDS_FeatureLocalFunctionAttributes: // syntax check
@@ -344,7 +344,7 @@ internal static LanguageVersion RequiredVersion(this MessageID feature)
                 case MessageID.IDS_FeatureStaticAnonymousFunction: // syntax check
                 case MessageID.IDS_FeatureModuleInitializers: // semantic check on method attribute
                 case MessageID.IDS_FeatureDefaultTypeParameterConstraint:
-                    return LanguageVersion.Preview;
+                    return LanguageVersion.CSharp9;
 
                 // C# 8.0 features.
                 case MessageID.IDS_FeatureAltInterpolatedVerbatimStrings:

src/Compilers/CSharp/Portable/LanguageVersion.cs

@@ -379,9 +379,7 @@ public static LanguageVersion MapSpecifiedToEffectiveVersion(this LanguageVersio
                 case LanguageVersion.Latest:
                 case LanguageVersion.Default:
                 case LanguageVersion.LatestMajor:
-                    return LanguageVersion.CSharp8;
-                case LanguageVersion.CSharp9:
-                    return LanguageVersion.Preview;
+                    return LanguageVersion.CSharp9;
                 default:
                     return version;
             }

src/Compilers/CSharp/Test/CommandLine/CommandLineTests.cs

@@ -1534,6 +1534,8 @@ public void ArgumentParsing()
         [InlineData("7.3", LanguageVersion.CSharp7_3)]
         [InlineData("8", LanguageVersion.CSharp8)]
         [InlineData("8.0", LanguageVersion.CSharp8)]
+        [InlineData("9", LanguageVersion.CSharp9)]
+        [InlineData("9.0", LanguageVersion.CSharp9)]
         [InlineData("preview", LanguageVersion.Preview)]
         public void LangVersion_CanParseCorrectVersions(string value, LanguageVersion expectedVersion)
         {
@@ -1655,7 +1657,6 @@ public void LanguageVersionAdded_Canary()
         {
             // When a new version is added, this test will break. This list must be checked:
             // - update the "UpgradeProject" codefixer
-            // - update the IDE drop-down for selecting Language Version (in project-systems repo)
             // - update all the tests that call this canary
             AssertEx.SetEqual(new[] { "default", "1", "2", "3", "4", "5", "6", "7.0", "7.1", "7.2", "7.3", "8.0", "9.0", "latest", "latestmajor", "preview" },
                 Enum.GetValues(typeof(LanguageVersion)).Cast<LanguageVersion>().Select(v => v.ToDisplayString()));
@@ -1709,10 +1710,11 @@ public void LanguageVersion_GetErrorCode()
             InlineData(LanguageVersion.CSharp7_2, LanguageVersion.CSharp7_2),
             InlineData(LanguageVersion.CSharp7_3, LanguageVersion.CSharp7_3),
             InlineData(LanguageVersion.CSharp8, LanguageVersion.CSharp8),
-            InlineData(LanguageVersion.CSharp8, LanguageVersion.LatestMajor),
-            InlineData(LanguageVersion.CSharp8, LanguageVersion.Latest),
-            InlineData(LanguageVersion.CSharp8, LanguageVersion.Default),
-            InlineData(LanguageVersion.Preview, LanguageVersion.CSharp9),
+            InlineData(LanguageVersion.CSharp9, LanguageVersion.CSharp9),
+            InlineData(LanguageVersion.CSharp9, LanguageVersion.LatestMajor),
+            InlineData(LanguageVersion.CSharp9, LanguageVersion.Latest),
+            InlineData(LanguageVersion.CSharp9, LanguageVersion.Default),
+            InlineData(LanguageVersion.Preview, LanguageVersion.Preview),
             ]
         public void LanguageVersion_MapSpecifiedToEffectiveVersion(LanguageVersion expectedMappedVersion, LanguageVersion input)
         {
@@ -7210,7 +7212,6 @@ public void SpecifyProperCodePage()
 a.cs(1,7): error CS1001: Identifier expected
 a.cs(1,7): error CS1514: { expected
 a.cs(1,7): error CS1513: } expected
-a.cs(1,7): error CS8652: The feature 'top-level statements' is currently in Preview and *unsupported*. To use Preview features, use the 'preview' language version.
 a.cs(1,7): error CS8803: Top-level statements must precede namespace and type declarations.
 a.cs(1,7): error CS1525: Invalid expression term '??'
 a.cs(1,9): error CS1525: Invalid expression term '{'

src/Compilers/CSharp/Test/Emit/Attributes/AttributeTests_CallerInfoAttributes.cs

@@ -389,7 +389,7 @@ static void log(
 line: 13
 ";
 
-            var compilation = CreateCompilation(source, options: TestOptions.ReleaseExe, parseOptions: TestOptions.RegularPreview);
+            var compilation = CreateCompilation(source, options: TestOptions.ReleaseExe, parseOptions: TestOptions.Regular9);
             CompileAndVerify(compilation, expectedOutput: expected);
         }
 
@@ -1133,7 +1133,7 @@ public static void Main()
             var compilation = CreateCompilation(
                 source,
                 options: TestOptions.ReleaseExe,
-                parseOptions: TestOptions.RegularPreview);
+                parseOptions: TestOptions.Regular9);
             CompileAndVerify(compilation, expectedOutput: expected);
         }
 
@@ -1179,7 +1179,7 @@ public static void Main()
             var compilation = CreateCompilation(
                 source,
                 options: TestOptions.ReleaseExe,
-                parseOptions: TestOptions.RegularPreview);
+                parseOptions: TestOptions.Regular9);
             CompileAndVerify(compilation, expectedOutput: expected);
         }
 
@@ -1228,7 +1228,7 @@ public static void Main()
             var compilation = CreateCompilation(
                 source,
                 options: TestOptions.ReleaseExe,
-                parseOptions: TestOptions.RegularPreview);
+                parseOptions: TestOptions.Regular9);
             CompileAndVerify(compilation, expectedOutput: expected);
         }
 
@@ -1696,7 +1696,7 @@ static void log([System.Runtime.CompilerServices.CallerFilePathAttribute] string
             var compilation = CreateCompilation(
                 new[]
                 {
-                    SyntaxFactory.ParseSyntaxTree(source1, options: TestOptions.RegularPreview, path: @"C:\filename", encoding: Encoding.UTF8)
+                    SyntaxFactory.ParseSyntaxTree(source1, options: TestOptions.Regular9, path: @"C:\filename", encoding: Encoding.UTF8)
                 },
                 options: TestOptions.ReleaseExe.WithSourceReferenceResolver(SourceFileResolver.Default));
 

src/Compilers/CSharp/Test/Emit/Attributes/AttributeTests_Experimental.cs

@@ -256,7 +256,7 @@ void local3()
         }
     }
 }";
-            var comp = CreateCompilationWithMscorlib40AndSystemCore(new[] { DeprecatedAttributeSource, ExperimentalAttributeSource, source }, parseOptions: TestOptions.RegularPreview);
+            var comp = CreateCompilationWithMscorlib40AndSystemCore(new[] { DeprecatedAttributeSource, ExperimentalAttributeSource, source }, parseOptions: TestOptions.Regular9);
             comp.VerifyDiagnostics(
                 // (7,9): warning CS0618: 'local1()' is obsolete: ''
                 //         local1(); // 1

src/Compilers/CSharp/Test/Emit/Attributes/AttributeTests_MarshalAs.cs

@@ -1398,7 +1398,7 @@ int ByValTStr
     }
 }
 ";
-            CreateCompilation(source, parseOptions: TestOptions.RegularPreview).VerifyDiagnostics(
+            CreateCompilation(source, parseOptions: TestOptions.Regular9).VerifyDiagnostics(
                     // (11,24): error CS7055: Unmanaged type 'ByValArray' is only valid for fields.
                     //             [MarshalAs(UnmanagedType.ByValArray)]
                     Diagnostic(ErrorCode.ERR_MarshalUnmanagedTypeOnlyValidForFields, "UnmanagedType.ByValArray").WithArguments("ByValArray").WithLocation(11, 24),