JS: Improve handling of Closure

Author: asgerf

javascript/ql/lib/semmle/javascript/GlobalAccessPaths.qll

@@ -272,6 +272,12 @@ module AccessPath {
       result = decl.getIdentifier().(GlobalVarDecl).getName() and
       root.isGlobal()
     )
+    or
+    exists(Closure::ClosureModule mod |
+      node = mod.getExportsVariable().getAnAssignedExpr().flow() and
+      root.isGlobal() and
+      result = mod.getClosureNamespace()
+    )
   }
 
   /** A module for computing an access to a variable that happens after a property has been written onto it */

javascript/ql/lib/semmle/javascript/dataflow/internal/CallGraphs.qll

@@ -14,7 +14,12 @@ module CallGraph {
   Function getAFunctionValue(AnalyzedNode node) {
     result = node.getAValue().(AbstractCallable).getFunction()
     or
-    node = NameResolution::trackFunctionValue(result).toDataFlowNode().(DataFlow::SourceNode)
+    node = NameResolution::trackFunctionValue(result).toDataFlowNode()
+    or
+    exists(DataFlow::Node pred |
+      AccessPath::step(pred, node) and
+      result = getAFunctionValue(pred)
+    )
   }
 
   /** Holds if the type inferred for `node` is indefinite due to global flow. */

javascript/ql/lib/semmle/javascript/internal/NameResolution.qll

@@ -194,11 +194,6 @@ module NameResolution {
       node2 = req
     )
     or
-    exists(Closure::ClosureModule mod |
-      node1 = mod.getExportsVariable() and
-      node2 = mod
-    )
-    or
     exists(ImmediatelyInvokedFunctionExpr fun, int i |
       node1 = fun.getArgument(i) and
       node2 = fun.getParameter(i)
@@ -319,6 +314,12 @@ module NameResolution {
     )
     or
     result = mod.(Closure::ClosureModule).getExportsVariable().getAnAssignedExpr()
+    or
+    exists(ExportDefaultDeclaration exprt |
+      mod instanceof Closure::ClosureModule and
+      exprt.getContainer() = mod and
+      result = exprt.getOperand()
+    )
   }
 
   /** Gets a node that is bulk-exported from the given module. */