JS: Implement type inference through export * as ns

Author: asgerf

javascript/ql/src/semmle/javascript/ES2015Modules.qll

@@ -545,14 +545,18 @@ class ReExportDefaultSpecifier extends ExportDefaultSpecifier {
 }
 
 /**
- * A namespace export specifier.
+ * A namespace export specifier, that is `*` or `* as x` occuring in an export declaration.
  *
- * Example:
+ * Examples:
  *
  * ```
  * export
  *   *          // namespace export specifier
  *   from 'a';
+ *
+ * export
+ *   * as x     // namespace export specifier
+ *   from 'a';
  * ```
  */
 class ExportNamespaceSpecifier extends ExportSpecifier, @exportnamespacespecifier { }
@@ -564,6 +568,7 @@ class ExportNamespaceSpecifier extends ExportSpecifier, @exportnamespacespecifie
  *
  * ```
  * export * from 'a';               // bulk re-export declaration
+ * export * as x from 'a';          // namespace re-export declaration
  * export { x } from 'a';           // named re-export declaration
  * export x from 'a';               // default re-export declaration
  * ```

javascript/ql/src/semmle/javascript/dataflow/internal/InterModuleTypeInference.qll

@@ -399,3 +399,16 @@ private class AnalyzedClosureGlobalAccessPath extends AnalyzedNode, AnalyzedProp
     )
   }
 }
+
+/**
+ * A namespace export declaration analyzed as a property write.
+ */
+private class AnalyzedExportNamespaceSpecifier extends AnalyzedPropertyWrite, DataFlow::ValueNode {
+  override ExportNamespaceSpecifier astNode;
+
+  override predicate writesValue(AbstractValue baseVal, string propName, AbstractValue value) {
+    baseVal = TAbstractExportsObject(getTopLevel()) and
+    propName = astNode.getExportedName() and
+    value = TAbstractExportsObject(astNode.getExportDeclaration().(ReExportDeclaration).getReExportedModule())
+  }
+}

javascript/ql/test/library-tests/CallGraphs/AnnotatedTest/Test.expected

@@ -2,5 +2,4 @@ spuriousCallee
 missingCallee
 | constructor-field.ts:40:5:40:14 | f3.build() | constructor-field.ts:13:3:13:12 | build() {} |
 | constructor-field.ts:71:1:71:11 | bf3.build() | constructor-field.ts:13:3:13:12 | build() {} |
-| reExportLibClient.js:4:1:4:6 | ns.f() | lib.js:3:2:3:14 | function() {} |
 badAnnotation