Fix analyzer RCS1264 (#1604)

Author: josefpihrt

ChangeLog.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fix refactoring 'Change accessibility' ([RR0186](https://josefpihrt.github.io/docs/roslynator/refactorings/RR0186)) ([PR](https://github.com/dotnet/roslynator/pull/1599))
+- Fix analyzer [RCS1264](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1264) ([PR](https://github.com/dotnet/roslynator/pull/1604))
 
 ### Changed
 

src/Analyzers/CSharp/Analysis/UseVarOrExplicitTypeAnalyzer.cs

@@ -48,7 +48,7 @@ private static void AnalyzeVariableDeclaration(SyntaxNodeAnalysisContext context
         }
         else if (style == TypeStyle.Explicit)
         {
-            if (CSharpTypeAnalysis.IsImplicitThatCanBeExplicit(variableDeclaration, context.SemanticModel, TypeAppearance.Obvious, context.CancellationToken))
+            if (CSharpTypeAnalysis.IsImplicitThatCanBeExplicit(variableDeclaration, context.SemanticModel, context.CancellationToken))
                 ReportImplicitToExplicit(context, variableDeclaration.Type);
         }
         else if (style == TypeStyle.ImplicitWhenTypeIsObvious)

src/Tests/Analyzers.Tests/RCS1264UseVarOrExplicitTypeTests2.cs

@@ -162,6 +162,36 @@ void M()
 ", options: Options.AddConfigOption(ConfigOptionKeys.UseVar, ConfigOptionValues.UseVar_Never));
     }
 
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UseVarOrExplicitType)]
+    public async Task Test_NotObviousExpression()
+    {
+        await VerifyDiagnosticAndFixAsync(@"
+using System.Threading.Tasks;
+using System.Collections.Generic;
+
+class C
+{
+    void M()
+    {
+        [|var|] x1 = string.Empty;
+        [|var|] x2 = Task.FromResult(string.Empty);
+    }
+}
+", @"
+using System.Threading.Tasks;
+using System.Collections.Generic;
+
+class C
+{
+    void M()
+    {
+        string x1 = string.Empty;
+        Task<string> x2 = Task.FromResult(string.Empty);
+    }
+}
+", options: Options.AddConfigOption(ConfigOptionKeys.UseVar, ConfigOptionValues.UseVar_Never));
+    }
+
     [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UseVarOrExplicitType)]
     public async Task TestNoDiagnostic_ForEach_DeclarationExpression()
     {