Fix NRE in AssigningSymbolAndItsMemberInSameStatement analyzer

Fixes dotnet#2889
mavasani · Oct 2, 2019 · 8047d1f · 8047d1f
1 parent 6c05175
commit 8047d1f
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Showing 2 changed files with 18 additions and 2 deletions.
diff --git a/...odeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs b/...odeQuality.Analyzers/Core/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatement.cs
@@ -80,8 +80,8 @@ private void AnalyzeAssignment(OperationAnalysisContext context)
             {
                 assignmentOperation = (ISimpleAssignmentOperation)assignmentOperation.Value;
 
-                var operationValue = assignmentOperation.Target as T;
-                if (equalityComparer(instance, operationValue))
+                if (assignmentOperation.Target is T operationValue &&
+                    equalityComparer(instance, operationValue))
                 {
                     return true;
                 }

diff --git a/....Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs b/....Analyzers/UnitTests/QualityGuidelines/AssigningSymbolAndItsMemberInSameStatementTests.cs
@@ -329,6 +329,22 @@ public unsafe void Method(Test a, Test *b)
         b->PtrField = a.PtrField;
     }
 }
+");
+        }
+
+        [Fact]
+        [WorkItem(2889, "https://github.com/dotnet/roslyn-analyzers/issues/2889")]
+        public void CSharpAssignmentLocalReferenceOperation()
+        {
+            VerifyCSharp(@"
+public static class Class1
+{
+    public static void Foo()
+    {
+        var u = new System.UriBuilder();
+        u.Host = u.Path = string.Empty;
+    }
+}
 ");
         }
     }