JS: Implement getTypingsFile() in PackageJsonEx

Author: asgerf

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

@@ -245,19 +245,7 @@ class PackageJson extends JsonObject {
    * Gets the file containing the typings of this package, which can either be from the `types` or
    * `typings` field, or derived from the `main` or `module` fields.
    */
-  File getTypingsFile() {
-    result =
-      TypingsModulePathString::of(this).resolve(this.getFile().getParentContainer()).getContainer()
-    or
-    not exists(TypingsModulePathString::of(this)) and
-    exists(File mainFile |
-      mainFile = this.getMainModule().getFile() and
-      result =
-        mainFile
-            .getParentContainer()
-            .getFile(mainFile.getStem().regexpReplaceAll("\\.d$", "") + ".d.ts")
-    )
-  }
+  File getTypingsFile() { none() } // implemented in PackageJsonEx
 
   /**
    * Gets the module containing the typings of this package, which can either be from the `types` or

javascript/ql/lib/semmle/javascript/internal/paths/PackageJsonEx.qll

@@ -70,6 +70,19 @@ class PackageJsonEx extends PackageJson {
   Container getAFileInFilesArray() {
     result = Resolver::resolve(this.getFolder(), this.getAPathInFilesArray())
   }
+
+  override File getTypingsFile() {
+    result = Resolver::resolve(this.getFolder(), this.getTypings())
+    or
+    not exists(this.getTypings()) and
+    exists(File mainFile |
+      mainFile = this.getMainFileOrBestGuess() and
+      result =
+        mainFile
+            .getParentContainer()
+            .getFile(mainFile.getStem().regexpReplaceAll("\\.d$", "") + ".d.ts")
+    )
+  }
 }
 
 private module ResolverConfig implements Folder::ResolveSig {
@@ -83,6 +96,8 @@ private module ResolverConfig implements Folder::ResolveSig {
       path = pkg.getMainPath()
       or
       path = pkg.getAPathInFilesArray()
+      or
+      path = pkg.getTypings()
     )
   }