JS: Fix in node.js classifier

change-notes/1.23/extractor-javascript.md

@@ -5,3 +5,6 @@
 ## Changes to code extraction
 
 * Asynchronous generator methods are now parsed correctly and no longer cause a spurious syntax error.
+
+* Recognition of CommonJS modules has improved. As a result, some files that were previously extracted as
+  global scripts are now extracted as modules.

javascript/extractor/src/com/semmle/js/extractor/Main.java

@@ -37,7 +37,7 @@ public class Main {
    * A version identifier that should be updated every time the extractor changes in such a way that
    * it may produce different tuples for the same file under the same {@link ExtractorConfig}.
    */
-  public static final String EXTRACTOR_VERSION = "2019-09-04";
+  public static final String EXTRACTOR_VERSION = "2019-09-13";
 
   public static final Pattern NEWLINE = Pattern.compile("\n");
 

javascript/extractor/src/com/semmle/js/extractor/NodeJSDetector.java

@@ -97,8 +97,9 @@ private static boolean isRequireCall(Expression e) {
     if (e instanceof CallExpression) {
       CallExpression call = (CallExpression) e;
       Expression callee = call.getCallee();
-      return (isIdentifier(callee, "require") || isRequireCall(callee))
-          && call.getArguments().size() == 1;
+      if (isIdentifier(callee, "require") && call.getArguments().size() == 1) return true;
+      if (isRequireCall(callee)) return true;
+      return false;
     } else if (e instanceof MemberExpression) {
       return isRequireCall(((MemberExpression) e).getObject());
     } else if (e instanceof AssignmentExpression) {

javascript/extractor/src/com/semmle/js/extractor/test/NodeJSDetectorTests.java

@@ -164,9 +164,8 @@ public void testUMD() {
 
   @Test
   public void amdefine() {
-    // not currently detected
     isNodeJS(
-        "if (typeof define !== 'function') define = require('amdefine')(module, require);", false);
+        "if (typeof define !== 'function') define = require('amdefine')(module, require);", true);
   }
 
   @Test
@@ -202,4 +201,14 @@ public void requireInIf() {
             + "}",
         true);
   }
+
+  @Test
+  public void requireAndCall() {
+    isNodeJS("var foo = require('foo')();", true);
+  }
+
+  @Test
+  public void requireAndCallMethod() {
+    isNodeJS("var foo = require('foo').bar();", true);
+  }
 }

javascript/ql/src/meta/analysis-quality/NumModules.ql

@@ -0,0 +1,14 @@
+/**
+ * @name Modules
+ * @description The number of modules in the snapshot.
+ * @kind metric
+ * @metricType project
+ * @metricAggregate sum
+ * @tags meta
+ * @id js/meta/modules
+ */
+
+import javascript
+import CallGraphQuality
+
+select projectRoot(), count(Module mod)