no-trailing-whitespace ignores trailing whitespace in comments

[ajafff]

Bug Report

• TSLint version: current master
• TypeScript version: 2.1.4
• Running TSLint via: cli

TypeScript code being linted

// comment with trailing spaces    
/* multiline comment 
    with trailing whitespace in first line */

with tslint.json configuration:

"no-trailing-whitespace": true

Actual behavior

no error

Expected behavior

// comment with trailing spaces    
                               ~~~~ [trailing whitespace]
/* multiline comment 
                    ~ [trailing whitespace]
   with trailing whitespace in first line */

Is this intended or can this be fixed? And should this be configurable with a config option?

The fix would not be difficult. I'd like to fix this if you want it

[nchen63]

Is there ever a valid reason for that? I'd prefer not to add an option if not, and just fix it

[Martinspire]

Why would you want to notify trailing whitespace in comments? Isn't the whole point of comments to not run any validations on it other than it being opened/closed properly?
I'd rather suggest to use a new rule like

"no-trailing-whitespace-comments": true

for that.

Sidenote, seems this does force you to use multi-line comments this will be reported as an error:

// some comment
// 
// some more comments

Though it shows up sometimes but not in others. Will investigate some more

[adidahiya]

Isn't the whole point of comments to not run any validations on it other than it being opened/closed properly?

I guess this is open to interpretation, but no, I don't think that's the whole point of comments. I don't see why you would want trailing whitespace in some part of your code and not others. If you and others feel strongly about it, you could send a PR to allow the rule to ignore comments.

[JoshuaKGoldberg]

^ this. I like having trailing whitespace in my TSDoc comments, but otherwise it's a waste.

/**
 *.{description}
 *.
 *.{params,etc}
 */

Config for the rule might want to include whether all comments are ignored or just TSDoc comments.