1618039 - try/catch accepts non-standard catch format

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Mark Straver]

Firefox seems to accept non-standard catch conditions in try/catch blocks.

According to the documentation, try/catch must always have a catch or finally statement, where the catch statement must always include an error object as a passed variable:

try {
  do something
} 
catch (error) {
  do something with error (or not)
}

However, it accepts catch without (error) too:

try {
  do something
} 
catch {
}

That seems wrong and non-standard to me?

Comment 1

[Tom S. (please needinfo tschuster)]

No it's part of ECMAScript 2019. This blog post explains it a bit.

Comment 2

[Mark Straver]

Can you please point me to the BZ bug then where you changed it so I can look at porting it? I haven't been able to find anything relevant before I posted this.

(Of note I find it a terrible change in ECMAScript allowing for this kind of further blurring syntax and setting up even more feature than can allow things to silently fail and make a terrible mess of debugging.)