JS: Implement babel-plugin-root-import as a PathMapping

Author: asgerf

javascript/ql/lib/semmle/javascript/frameworks/Babel.qll

@@ -3,6 +3,7 @@
  */
 
 import javascript
+private import semmle.javascript.internal.paths.PathMapping
 
 module Babel {
   /**
@@ -202,4 +203,12 @@ module Babel {
       )
     }
   }
+
+  private class BabelPathMapping extends PathMapping, RootImportConfig {
+    override File getAnAffectedFile() { result = this.getConfig().getAContainerInScope() }
+
+    override predicate hasPrefixPathMapping(string pattern, Container newContext, string newPath) {
+      newPath = this.getRoot(pattern) and newContext = this.getFolder()
+    }
+  }
 }