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Re: [SCXML] Incorrect and invalid ecmascript condition in IR test 459

From: Ate Douma <ate@douma.nu>
Date: Tue, 29 Dec 2015 01:47:46 +0100
To: www-voice@w3.org
Message-ID: <5681D832.2010003@douma.nu>
On 2015-12-28 21:06, David Junger wrote:
> Le 28 déc. 2015 à 17:18, Ate Douma <ate@douma.nu> a écrit :
>>
>> I've just noticed an error in Implementation Report test 459 (ecmascript).
>>
>> This test contains the incorrect (and invalid!) ecmascript condition:
>>
>> "Var4==0 | Var3 != 2".
>
> It’s not technically invalid, and it’s not functionally broken either,
> although probably by accident.
>
> ‘|’ is a bitwise OR, has lower priority than comparison operators, and, when
> its operands are booleans (which they are here), it coerces them to 0 or 1
> and so the result is 0 or 1, which is coerced back to the expected boolean.
>
> David
>
Agreed, I probably shouldn't have said "invalid" :).
And indeed its not that this test always will succeed, but at least it (always)
fails to validate that Var1 and/or Var5 shouldn't be 0 at the end.

What I wanted to say is that there are two different type of errors with the
current expression:

   "Var4==0" should be "Var5==0" (error)
and
   bitwise OR "|" should be logical OR "||" (invalid)

I suspect this test has been modified heavily in the past as the comments
(including the description) don't add up to the applied logic either,
referring to either Var4 or var1 to be tested while I now think it is Var5 which 
is intended to be tested (being not 0).

Anyhow, I think the current expression really is incorrect and also more
confusing as a negative test.
It would be much easier and strict when defined like:

   <transition cond="Var5 == 1 &amp;&amp; Var3 == 2" target="pass"/>
   <transition target="fail"/>

Ate
Received on Tuesday, 29 December 2015 00:48:18 UTC

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