978232 - ES6 Proxies: [[Construct]] hook doesn't throw if handler hook doesn't return an object.

Status: RESOLVED FIXED

(Core :: JavaScript: Standard Library, defect)

Description

[Eric Faust [:efaust]]

This is trivial. We just have to do it.

Comment 1

[Eric Faust [:efaust]]

Attachment: Trivial test case.

A simple test case that should throw, but doesn't

Comment 2

[Eric Faust [:efaust]]

Attachment: Throw if the trap return value is not an object

Fix with test

Comment 3

[Eric Faust [:efaust]]

Attachment: Throw if the trap return value is not an object

Missed out on updating a test

Comment 4

[Jeff Walden [:Waldo]]

Comment on attachment 8387151 [details] [diff] [review]
Throw if the trap return value is not an object

Review of attachment 8387151 [details] [diff] [review]:
-----------------------------------------------------------------

Swiped, given offhand mention on IRC that I should feel free to take a look at this.

The error message might be kind of internal-ish reading, but I'm not inclined to wordsmith too hard right now.

::: js/src/tests/ecma_6/Proxy/proxy-constructNonObject.js
@@ +1,1 @@
> +function bogusConstruct(target) { return 4; }

Add a second one:

function bogusConstruct(target) {}

and test that as well.  The |handler.construct| invoked during construction, is invoked by calling it.  So this method returns |undefined|, a primitive, and construction should fail.

@@ +1,3 @@
> +function bogusConstruct(target) { return 4; }
> +
> +var handler = { construct: bogusConstruct }

Trailing semicolon?  Do not want ASI.

@@ +12,5 @@
> +} catch(e) {
> +    threw = true
> +}
> +
> +reportCompare(threw, true, "[[Construct]] must throw if an object is not returned");

Use assertEq, and add

if (typeof reportCompare === "function")
  reportCompare(true, true);

at the end.  assertEq's arguments order actual/expected in that order, but reportCompare inverts them, and nobody expects that ordering.  (Plus this makes the test runnable standalone, without spinning up the whole jstests harness monstrosity.)

Comment 5

[Eric Faust [:efaust]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/037edc1bb501

Comment 6

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/037edc1bb501