C#: Add more tests for cs/local-not-disposed

Author: hvitved

csharp/ql/test/query-tests/API Abuse/NoDisposeCallOnLocalIDisposable/NoDisposeCallOnLocalIDisposable.cs

@@ -1,4 +1,4 @@
-// semmle-extractor-options: --cil /r:System.Xml.dll /r:System.Xml.ReaderWriter.dll /r:System.Private.Xml.dll /r:System.ComponentModel.Primitives.dll /r:System.IO.Compression.dll /r:System.Runtime.Extensions.dll
+// semmle-extractor-options: --cil /langversion:8.0 /r:System.Xml.dll /r:System.Xml.ReaderWriter.dll /r:System.Private.Xml.dll /r:System.ComponentModel.Primitives.dll /r:System.IO.Compression.dll /r:System.Runtime.Extensions.dll
 
 using System;
 using System.Text;
@@ -51,6 +51,7 @@ public IDisposable Method()
         // BAD: No Dispose call
         var c1d = new Timer(TimerProc);
         var fs = new FileStream("", FileMode.CreateNew, FileAccess.Write);
+        new FileStream("", FileMode.CreateNew, FileAccess.Write).Fluent();
 
         // GOOD: Disposed via wrapper
         fs = new FileStream("", FileMode.CreateNew, FileAccess.Write);
@@ -65,6 +66,7 @@ public IDisposable Method()
         d = new GZipStream(fs, CompressionMode.Compress);
         dProp = new Timer(TimerProc);
         this[0] = new Timer(TimerProc);
+        d = new FileStream("", FileMode.CreateNew, FileAccess.Write).Fluent(); // FALSE POSITIVE
 
         // GOOD: Passed to another IDisposable
         using (var reader = new StreamReader(new FileStream("", FileMode.Open)))
@@ -90,6 +92,11 @@ public IDisposable Method()
     void TimerProc(object obj)
     {
     }
+
+    public void Dispose() { }
 }
 
-// semmle-extractor-options: /langversion:8.0
+static class Extensions
+{
+    public static FileStream Fluent(this FileStream fs) => fs;
+}

csharp/ql/test/query-tests/API Abuse/NoDisposeCallOnLocalIDisposable/NoDisposeCallOnLocalIDisposable.expected

@@ -1,4 +1,6 @@
 | NoDisposeCallOnLocalIDisposable.cs:52:19:52:38 | object creation of type Timer | Disposable 'Timer' is created here but is not disposed. |
 | NoDisposeCallOnLocalIDisposable.cs:53:18:53:73 | object creation of type FileStream | Disposable 'FileStream' is created here but is not disposed. |
-| NoDisposeCallOnLocalIDisposable.cs:74:25:74:71 | call to method Create | Disposable 'XmlReader' is created here but is not disposed. |
+| NoDisposeCallOnLocalIDisposable.cs:54:9:54:64 | object creation of type FileStream | Disposable 'FileStream' is created here but is not disposed. |
+| NoDisposeCallOnLocalIDisposable.cs:69:13:69:68 | object creation of type FileStream | Disposable 'FileStream' is created here but is not disposed. |
+| NoDisposeCallOnLocalIDisposable.cs:76:25:76:71 | call to method Create | Disposable 'XmlReader' is created here but is not disposed. |
 | NoDisposeCallOnLocalIDisposableBad.cs:8:22:8:56 | object creation of type FileStream | Disposable 'FileStream' is created here but is not disposed. |