C#: Classify test support files in model editor queries

csharp/ql/src/utils/modeleditor/FrameworkModeEndpointsQuery.qll

@@ -7,7 +7,11 @@ private import ModelEditor
  * A class of effectively public callables from source code.
  */
 class PublicEndpointFromSource extends Endpoint {
-  PublicEndpointFromSource() { this.fromSource() and not this.getFile() instanceof TestFile }
+  PublicEndpointFromSource() {
+    this.fromSource() and
+    not this.getFile() instanceof TestFile and
+    not this.getFile() instanceof TestSupportFile
+  }
 
   override predicate isSource() { this instanceof SourceCallable }
 

csharp/ql/src/utils/modeleditor/ModelEditor.qll

@@ -110,9 +110,11 @@ string supportedType(Endpoint endpoint) {
 }
 
 string methodClassification(Call method) {
-  method.getFile() instanceof TestFile and result = "test"
+  (method.getFile() instanceof TestFile or method.getFile() instanceof TestSupportFile) and
+  result = "test"
   or
   not method.getFile() instanceof TestFile and
+  not method.getFile() instanceof TestSupportFile and
   result = "source"
 }
 
@@ -129,3 +131,12 @@ private string qualifiedTypeName(string namespace, Type t) {
 private string qualifiedCallableName(string namespace, string type, Callable c) {
   exists(string name | hasQualifiedMethodName(c, namespace, type, name) | result = name)
 }
+
+/** A file that doesn't contain tests itself, but is only used in tests. */
+class TestSupportFile extends File {
+  TestSupportFile() {
+    not this instanceof TestFile and
+    this.getAbsolutePath().matches(["%/test/%", "%/tests/%"]) and
+    not this.getAbsolutePath().matches("%/ql/test/%") // allows our test cases to work
+  }
+}