JS: More efficient nested package naming

Author: asgerf

javascript/ql/lib/semmle/javascript/NPM.qll

@@ -22,25 +22,25 @@ class PackageJson extends JsonObject {
   pragma[nomagic]
   string getDeclaredPackageName() { result = this.getPropStringValue("name") }
 
+  private PackageJson getEnclosingNamedPackage() {
+    result.getFolder() = packageInternalParent*(this.getFolder().getParentContainer()) and
+    not result.isPrivate() and
+    exists(result.getDeclaredPackageName())
+  }
+
   /**
    * Gets the name of this package.
    * If the package is located under the package `pkg1` and its relative path is `foo/bar`, then the resulting package name will be `pkg1/foo/bar`.
    */
   string getPackageName() {
     result = this.getDeclaredPackageName()
     or
-    exists(
-      PackageJson parentPkg, Container currentDir, Container parentDir, string parentPkgName,
-      string pkgNameDiff
-    |
-      currentDir = this.getJsonFile().getParentContainer() and
-      parentDir = parentPkg.getJsonFile().getParentContainer() and
-      parentPkgName = parentPkg.getPropStringValue("name") and
-      parentDir.getAChildContainer+() = currentDir and
-      pkgNameDiff = currentDir.getAbsolutePath().suffix(parentDir.getAbsolutePath().length()) and
-      not exists(pkgNameDiff.indexOf("/node_modules/")) and
-      result = parentPkgName + pkgNameDiff and
-      not parentPkg.isPrivate()
+    not exists(this.getDeclaredPackageName()) and
+    exists(PackageJson parent |
+      parent = this.getEnclosingNamedPackage() and
+      result =
+        parent.getDeclaredPackageName() +
+          this.getFolder().getRelativePath().suffix(parent.getFolder().getRelativePath().length())
     )
   }
 
@@ -405,5 +405,6 @@ class NpmPackage extends @folder {
  */
 private Folder packageInternalParent(Container c) {
   result = c.getParentContainer() and
-  not c.(Folder).getBaseName() = "node_modules"
+  not c.(Folder).getBaseName() = "node_modules" and
+  not c = any(PackageJson pkg).getFolder()
 }

javascript/ql/test/library-tests/NPM/tests.expected

@@ -39,7 +39,6 @@ modules
 | src/node_modules/nested | nested | src/node_modules/nested/tst3.js:1:1:2:13 | <toplevel> |
 | src/node_modules/nested/node_modules/a | a | src/node_modules/nested/node_modules/a/index.js:1:1:1:25 | <toplevel> |
 | src/node_modules/parent-module | parent-module | src/node_modules/parent-module/main.js:1:1:2:0 | <toplevel> |
-| src/node_modules/parent-module | parent-module | src/node_modules/parent-module/sub-module/main.js:1:1:2:0 | <toplevel> |
 | src/node_modules/parent-module/sub-module | parent-module/sub-module | src/node_modules/parent-module/sub-module/main.js:1:1:2:0 | <toplevel> |
 | src/node_modules/third-party-module | third-party-module | src/node_modules/third-party-module/fancy.js:1:1:4:0 | <toplevel> |
 npm