Jasmine Swallows Error Message when throwing own Exception

[despairblue]

Doing something like this in the code that's going to be tested (or in an it):

var MyError = function (message) {
  this.message = message
}
MyError.prototype = new Error('foo')
var myerror = new MyError('bar')
console.log(myerror instanceof Error)
console.log(myerror.message)
throw myerror

Jasmine will report this:

You see that jasmine seems to report the prototypes message. Not the one from myerror. Is this me misunderstanding prototypes or is this actually some kind of error in jasmine?

[despairblue]

By the way, my actual problem is that peg.js constructs it's own SyntaxErrors like this:

function peg$subclass(child, parent) {
    function ctor() { this.constructor = child; }
    ctor.prototype = parent.prototype;
    child.prototype = new ctor();
  }

  function SyntaxError(message, expected, found, offset, line, column) {
    this.message  = message;
    this.expected = expected;
    this.found    = found;
    this.offset   = offset;
    this.line     = line;
    this.column   = column;

    this.name     = "SyntaxError";
  }

  peg$subclass(SyntaxError, Error);

And jasmine won't report these errors.

The actual error caught with try catch:

[sheelc]

It looks like theres a bit of an inconsistency between the browser reporter and the console reporter. The browser reporter prints out both the message and stack, while the console reporter only prints the stack. I just pushed a commit to fix that.

The message shown in the browser is the message you have overridden ('bar') while the stack contains the offending 'foo', since the stack property hasn't been overridden. As this stack overflow post suggests, you could override the stack property as well to be something like (new Error()).stack to remove the misleading 'Error: foo' and only see 'Error' instead.

Does this help resolve the issue?

[despairblue]

Yep, that helps. Now I'll can see why the spec failed. Thanks 👍
And overriding the stack property (or actually having one one in the first) place is something I'll suggest to the peg.js maintainer