Bug 147656 – Poor Error Message / Call Stack for TypeError: Cannot call a class constructor

• Status: NEW
• Component: JavaScriptCore

[Joseph Pecoraro]

* SUMMARY
Poor Error Message / Call Stack for TypeError: Cannot call a class constructor. It points to the "constructor" instead of the "call" site.

* TEST:

  1  <script>
  2  class MyClass {
  3      constructor() { this.name = "name"; }
  4  }
  5  function OtherClass() {
  6      MyClass.call(this);
  7  }
  8  x = new OtherClass;
  9  </script>


* STEPS TO REPRODUCE
1. Run attached test case
  => Error in console points to the "constructor" line, expected it to point to the frame above, the "call" site.
  TypeError: Cannot call a class constructor
    MyClass test.html:3
    OtherClass test.html:6
    (anonymous function) test.html:8

* NOTES
- Inspector currently has an off by 1 error in its stack trace output which is getting corrected at the moment.

[Joseph Pecoraro]

Also it might be good to use the class' name if it has one. It might not though.