bugfix: fix analyzer for issue #300 and #299 (#303)

* bugfix: fix analyzer for issue #300

* bugfix: fix issue 299

Author: Meir017

Diff for: src/FluentAssertions.Analyzers.Tests/Tips/CollectionTests.cs

@@ -320,6 +320,13 @@ public class CollectionTests
         [Implemented]
         public void CollectionShouldHaveCount_LengthShouldBe_TestAnalyzer(string assertion) => VerifyCSharpDiagnosticCodeBlock(assertion, DiagnosticMetadata.CollectionShouldHaveCount_LengthShouldBe);
 
+        [DataTestMethod]
+        [AssertionDiagnostic("actual.Should().HaveCount(expected.Count() + 1{0});")]
+        [AssertionDiagnostic("actual.Should().HaveCount(expected.Count() + unexpected.Count(){0});")]
+        [AssertionDiagnostic("actual.Should().HaveCount(expected.Count + unexpected.Count{0});")]
+        [Implemented(Reason = "https://github.com/fluentassertions/fluentassertions.analyzers/issues/300")]
+        public void CollectionShouldHaveCount_TestNoAnalyzer(string assertion) => DiagnosticVerifier.VerifyCSharpDiagnosticUsingAllAnalyzers(GenerateCode.GenericIListCodeBlockAssertion(assertion));
+
         [DataTestMethod]
         [AssertionCodeFix(
             oldAssertion: "actual.Count().Should().Be(k{0});",
@@ -533,6 +540,13 @@ public class CollectionTests
         [Implemented]
         public void CollectionShouldHaveSameCount_TestAnalyzer(string assertion) => VerifyCSharpDiagnosticCodeBlock(assertion, DiagnosticMetadata.CollectionShouldHaveSameCount_ShouldHaveCountOtherCollectionCount);
 
+        [DataTestMethod]
+        [AssertionDiagnostic("actual.Should().HaveCount(expected.Count() + 1{0});")]
+        [AssertionDiagnostic("actual.Should().HaveCount(expected.Count() + unexpected.Count(){0});")]
+        [AssertionDiagnostic("actual.Should().HaveCount(1 + expected.Count(){0});")]
+        [Implemented(Reason = "https://github.com/fluentassertions/fluentassertions.analyzers/issues/300")]
+        public void CollectionShouldHaveSameCount_TestNoAnalyzer(string assertion) => DiagnosticVerifier.VerifyCSharpDiagnosticUsingAllAnalyzers(GenerateCode.GenericIListCodeBlockAssertion(assertion));
+
         [DataTestMethod]
         [AssertionCodeFix(
             oldAssertion: "actual.Should().HaveCount(expected.Count(){0});",
@@ -903,6 +917,11 @@ public void CollectionShouldContainSingle_TestAnalyzer_GenericIEnumerableShouldR
         [Implemented]
         public void CollectionShouldOnlyHaveUniqueItems_TestAnalyzer(string assertion) => VerifyCSharpDiagnosticCodeBlock(assertion, DiagnosticMetadata.CollectionShouldOnlyHaveUniqueItems_ShouldHaveSameCountThisCollectionDistinct);
 
+        [DataTestMethod]
+        [AssertionDiagnostic("actual.Should().HaveSameCount(expected.Distinct(){0});")]
+        [Implemented(Reason = "https://github.com/fluentassertions/fluentassertions.analyzers/issues/299")]
+        public void CollectionShouldOnlyHaveUniqueItems_TestNoAnalyzer(string assertion) => DiagnosticVerifier.VerifyCSharpDiagnosticUsingAllAnalyzers(GenerateCode.GenericIListCodeBlockAssertion(assertion));
+
         [DataTestMethod]
         [AssertionCodeFix(
             oldAssertion: "actual.Should().HaveSameCount(actual.Distinct(){0});",
@@ -1032,7 +1051,7 @@ private void VerifyCSharpFixExpressionBody(string oldSourceAssertion, string new
         {
             var oldSource = GenerateCode.GenericIListExpressionBodyAssertion(oldSourceAssertion);
             var newSource = GenerateCode.GenericIListExpressionBodyAssertion(newSourceAssertion);
-            
+
             VerifyFix(oldSource, newSource);
         }
 

Diff for: src/FluentAssertions.Analyzers/Tips/FluentAssertionsOperationAnalyzer.cs

@@ -57,7 +57,8 @@ private static void AnalyzeInvocation(OperationAnalysisContext context, FluentAs
             return;
         }
 
-        var subject = invocation.Arguments[0].Value;
+        var subjectArgument = invocation.Arguments[0];
+        var subject = subjectArgument.Value;
 
         switch (assertion.TargetMethod.Name)
         {
@@ -289,10 +290,11 @@ private static void AnalyzeInvocation(OperationAnalysisContext context, FluentAs
             case "HaveCount" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3) && assertion.Arguments[0].IsLiteralValue(0):
                 context.ReportDiagnostic(CreateDiagnostic(assertion, DiagnosticMetadata.CollectionShouldBeEmpty_ShouldHaveCount0));
                 return;
-            case "HaveCount" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3) && assertion.Arguments[0].HasFirstDescendentInvocation(nameof(Enumerable.Count)):
+            case "HaveCount" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3) && assertion.Arguments[0].Value is IInvocationOperation { TargetMethod.Name: nameof(Enumerable.Count) }:
                 context.ReportDiagnostic(CreateDiagnostic(assertion, DiagnosticMetadata.CollectionShouldHaveSameCount_ShouldHaveCountOtherCollectionCount));
                 return;
-            case "HaveSameCount" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3) && assertion.Arguments[0].HasFirstDescendentInvocation(nameof(Enumerable.Distinct)):
+            case "HaveSameCount" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3) && assertion.Arguments[0].Value is IInvocationOperation { TargetMethod.Name: nameof(Enumerable.Distinct) } assertionArgumentInvocation
+                && assertionArgumentInvocation.Arguments[0].IsSameArgumentReference(subjectArgument):
                 context.ReportDiagnostic(CreateDiagnostic(assertion, DiagnosticMetadata.CollectionShouldOnlyHaveUniqueItems_ShouldHaveSameCountThisCollectionDistinct));
                 return;
             case "OnlyHaveUniqueItems" when assertion.IsContainedInType(metadata.GenericCollectionAssertionsOfT3):