FileConventions: add failing test

Add tests for NotFollowingNamespaceConvention function.

src/FileConventions.Test/DummyFiles/src/Foo/DummyFileUnderFooWithRightNamespace.fs

@@ -0,0 +1 @@
+namespace Foo

src/FileConventions.Test/DummyFiles/src/Foo/DummyFileUnderFooWithWrongNamespace.fs

@@ -0,0 +1 @@
+namespace Baz

src/FileConventions.Test/FileConventions.Test.fs

@@ -603,3 +603,33 @@ let ProjFilesNamingConvention2() =
         ))
 
     Assert.That(ProjFilesNamingConvention fileInfo, Is.EqualTo true)
+
+
+[<Test>]
+let NamespaceConvention1() =
+    let fileInfo =
+        (FileInfo(
+            Path.Combine(
+                dummyFilesDirectory.FullName,
+                "src",
+                "Foo",
+                "DummyFileUnderFooWithRightNamespace.fs"
+            )
+        ))
+
+    Assert.That(NotFollowingNamespaceConvention fileInfo, Is.EqualTo false)
+
+
+[<Test>]
+let NamespaceConvention2() =
+    let fileInfo =
+        (FileInfo(
+            Path.Combine(
+                dummyFilesDirectory.FullName,
+                "src",
+                "Foo",
+                "DummyFileUnderFooWithWrongNamespace.fs"
+            )
+        ))
+
+    Assert.That(NotFollowingNamespaceConvention fileInfo, Is.EqualTo true)

src/FileConventions/Library.fs

@@ -402,3 +402,7 @@ let ProjFilesNamingConvention(fileInfo: FileInfo) =
         parentDirectoryName
 
     fileName <> parentDirectoryName
+
+let NotFollowingNamespaceConvention(fileInfo: FileInfo) =
+    printfn "%s" fileInfo.FullName
+    false