JS: support FP pattern for js/unbound-event-handler-receiver

Author: Esben Sparre Andreasen

javascript/ql/src/Expressions/UnboundEventHandlerReceiver.ql

@@ -18,7 +18,15 @@ private predicate isBoundInMethod(MethodDeclaration method) {
     bindingMethod.getDeclaringClass() = method.getDeclaringClass() and
     not bindingMethod.isStatic() and
     thiz.getBinder().getAstNode() = bindingMethod.getBody()
-  |
+    |
+    exists (DataFlow::MethodCallNode bind, DataFlow::PropWrite w |
+      // this[x] = <expr>.bind(...)
+      w = thiz.getAPropertyWrite() and
+      not exists(w.getPropertyName()) and
+      bind.getMethodName() = "bind" and
+      bind.flowsTo(w.getRhs())
+    )
+    or
     // require("auto-bind")(this)
     thiz.flowsTo(DataFlow::moduleImport("auto-bind").getACall().getArgument(0))
     or

javascript/ql/test/query-tests/Expressions/UnboundEventHandlerReceiver/tst.js

@@ -134,4 +134,25 @@ class Component2 extends React.Component {
     }
 
 }
+
+class Component3 extends React.Component {
+
+    render() {
+        return <div>
+            <div onClick={this.bound_throughIterator}/> // OK
+            </div>
+    }
+
+    constructor(props) {
+        super(props);
+	    Object.getOwnPropertyNames( Component3.prototype )
+		    .filter( prop => typeof this[ prop ] === 'function' )
+		    .forEach( prop => ( this[ prop ] = this[ prop ].bind( this ) ) );
+    }
+
+    bound_throughIterator() {
+        this.setState({ });
+    }
+}
+
 // semmle-extractor-options: --experimental