JS: Exclude template files in SelfAssignment

Author: asgerf

javascript/ql/src/Expressions/SelfAssignment.ql

@@ -43,5 +43,8 @@ where
   // exclude DOM properties
   not isDOMProperty(e.(PropAccess).getPropertyName()) and
   // exclude self-assignments that have been inserted to satisfy the TypeScript JS-checker
-  not e.getAssignment().getParent().(ExprStmt).getDocumentation().getATag().getTitle() = "type"
+  not e.getAssignment().getParent().(ExprStmt).getDocumentation().getATag().getTitle() = "type" and
+  // exclude self-assignments in speculatively parsed template files
+  // named arguments may be incorrectly parsed as assignments
+  not e.getTopLevel() instanceof Templating::TemplateTopLevel
 select e.getParent(), "This expression assigns " + dsc + " to itself."

javascript/ql/test/query-tests/Expressions/SelfAssignment/template.njk

@@ -0,0 +1,3 @@
+<div>
+    {{ foo(x=x) }}
+</div>