JS: More doc

Author: asgerf

javascript/ql/lib/semmle/javascript/Paths.qll

@@ -96,7 +96,7 @@ deprecated private class ConsPath extends Path, TConsPath {
 private string pathRegex() { result = "(.*)(?:/|^)(([^/]*?)(\\.([^.]*))?)" }
 
 /**
- * A `string` with some additional member predicates for extracting parts of a path string.
+ * A `string` with some additional member predicates for extracting parts of the file path.
  */
 class FilePath extends string {
   bindingset[this]
@@ -147,8 +147,14 @@ class FilePath extends string {
   predicate isDotRelativePath() { this.regexpMatch("\\.\\.?(?:[/\\\\].*)?") }
 
   /**
-   * Gets the NPM package name from the beginning of the given import path, e.g.
-   * gets `foo` from `foo/bar`, and `@example/foo` from `@example/foo/bar`.
+   * Gets the NPM package name from the beginning of the given import path.
+   *
+   * Has no result for paths starting with a `.` or `/`
+   *
+   * For example:
+   * - `foo/bar` maps to `foo`
+   * - `@example/foo/bar` maps to `@example/foo`
+   * - `./foo` maps to nothing.
    */
   bindingset[this]
   string getPackagePrefix() {