1242729 - Don't add line break for empty object and array literals ( `{}`, `[]`)

Status: RESOLVED FIXED

(DevTools :: Source Editor, enhancement, P3)

Description

[PK]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0
Build ID: 20160124004010

Steps to reproduce:

Just open dev tools with some minified source and click "prettify" on the bottom.
Got the issue on 45 but probably it could exist in any previous stable version.


Actual results:

Looks like it prettifies simply by injecting line break after { or [. I am not sure if this should be applicable for object literals in constructions like this:
var a = {};
var b = [];
Internal prettifier makes those:
var a = {
};
var b = [
];



Expected results:

should be var a = {}, b = [] (no line break for literals without keys/values)

Comment 1

[Loic]

Coul you attach a simple minified source file as testcase, please.

Comment 2

[PK]

(In reply to Loic from comment #1)
> Coul you attach a simple minified source file as testcase, please.

The simple stub like this is enough: 
<script src='https://code.jquery.com/jquery-1.12.0.min.js'></script>

Not sure would this make any help if I attach minified jquery

Comment 3

[Brian Grinstead [:bgrins]]

(In reply to PK from comment #0)
> Looks like it prettifies simply by injecting line break after { or [. I am
> not sure if this should be applicable for object literals in constructions
> like this:
> var a = {};
> var b = [];
> Internal prettifier makes those:
> var a = {
> };
> var b = [
> ];
> 
> 
> 
> Expected results:
> 
> should be var a = {}, b = [] (no line break for literals without keys/values)

I'm not sure about pushing them onto one line and removing the second var, but I agree that adding a new line for empty object / array literals seems off.

Given 
  var a = {};
  var b = [];

I think the prettifier should just leave it alone.  Nick, any opinion?

Comment 4

[PK]

(In reply to Brian Grinstead [:bgrins] from comment #3)
> (In reply to PK from comment #0)
> > Looks like it prettifies simply by injecting line break after { or [. I am
> > not sure if this should be applicable for object literals in constructions
> > like this:
> > var a = {};
> > var b = [];
> > Internal prettifier makes those:
> > var a = {
> > };
> > var b = [
> > ];
> > 
> > 
> > 
> > Expected results:
> > 
> > should be var a = {}, b = [] (no line break for literals without keys/values)
> 
> I'm not sure about pushing them onto one line and removing the second var,
> but I agree that adding a new line for empty object / array literals seems
> off.
> 
> Given 
>   var a = {};
>   var b = [];
> 
> I think the prettifier should just leave it alone.  Nick, any opinion?

No need to push on one line vars, just to remove line break between [ ] and {} when there are no keys/values.

Comment 5

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

(In reply to Brian Grinstead [:bgrins] from comment #3)
> Given 
>   var a = {};
>   var b = [];
> 
> I think the prettifier should just leave it alone.  Nick, any opinion?

Sure, if we can do it without slowing down the prettifier or complicating its logic.

The goal of the prettifier was never to produce beautiful code as you would have written it -- it was to be fast despite generating source maps, and produce readable output.

Comment 6

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1242729 - [devtools] Don't add new line for empty array literal. r=#devtools-reviewers.

Depends on D174281

Comment 7

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1242729 - [devtools] Don't add new line for empty object literal. r=#devtools-reviewers.

Depends on D174946

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ddda87f27af5
[devtools] Don't add new line for empty array literal. r=devtools-reviewers,ochameau.
https://hg.mozilla.org/integration/autoland/rev/be68826cf661
[devtools] Don't add new line for empty object literal. r=devtools-reviewers,ochameau.

Comment 9

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/ddda87f27af5
https://hg.mozilla.org/mozilla-central/rev/be68826cf661