PSAvoidTrailingWhitespace should ignore empty lines indented to match the current block

[poshcodebear]

Currently, PSAvoidTrailingWhitespace checks all lines for trailing whitespace, even when that line is effectively empty and the "trailing" whitespace is actually leading whitespace for the current indentation level. If the recommended action is taken (remove the whitespace), then adding new code in those spots requires re-indenting that spot to the current code indentation level.

I propose that it should respect the current indentation level for an empty line and not generate a note for those lines, as long as they match the indentation of the current block of code.

What is the latest version of PSScriptAnalyzer at the point of writing
1.17.1, shipping with the vscode-powershell extension version 1.8.1

[bergmeister]

Thanks for the feedback. Which editor do you use that results in having such lines? I think the default behaviour is maybe ok but having a configuration option for the rule to ignore lines with whitespace only would make sense to me.

[poshcodebear]

As implied, I use Visual Studio Code; that being said, every modern editor I've used (VSCode, ISE, Notepad++, Atom, Visual Studio) does the exact same thing: retains the current indentation line when I press enter. If I hit enter twice, I have an empty line at the same indentation level as the code around it.

I would be fine with that solution, assuming it doesn't mean having to create a settings file for every repo I work in just for that one setting.

[bergmeister]

Ok. I see. In VSCode one can set the setting files.trimTrailingWhitespace to true and on saving the document the trailing whitespace will get removed automatically.
One can even tweak the rule to make it only apply to PowerShell files as follows:

 "[powershell]": {
    "files.trimTrailingWhitespace": true
  },

[poshcodebear]

I'm not so much looking for it to automatically handle it for me; additionally, I want the automatically inserted whitespace that matches the indentation level to remain (this makes future changes easier as I don't have to stop and re-indent lines that should already be indented correctly).

Up until the last update to the PowerShell extension which pushed this latest version of PSScriptAnalyzer, I've not had to create a settings file to control its behavior as it's been fine out of the box. I get an update and all of a sudden it's complaining about perfectly legitimate use of whitespace and I'm finding the only way to get it to quiet down is either to manually turn that check off every time I launch or create a settings file for every PowerShell folder I work with. Neither of these solutions are particularly appealing, and I don't want to turn it off either, but I find the behavior that it insists on baffling and without any explanation (the documentation/description only lists issues with trailing whitespace at the end of code lines, not at the end of blank lines).

Anyway, if the behavior won't be changed, I feel that the description should at least be updated with a defense of that as a standard.

[bergmeister]

OK, I see now where you're coming from and understand your pain. My current thinking is that it might be be better to rather change the defaults in the VSCode extension to use a new customisation of this rule to allow whitespace only lines. I think we could discuss the defaults of this customisation afterwards depending on what other people think but having the customisation and using it in the defaults of the extension (to be precise, it is actually PowerShellEditorServices, which applies to other editor as well) sounds reasonable.
Since this depends on a new PSSA release, would it be better to turn this rule not on by default for the moment @tylerl0706 ?

[SeeminglyScience]

every modern editor I've used (VSCode, ISE, Notepad++, Atom, Visual Studio) does the exact same thing: retains the current indentation line when I press enter. If I hit enter twice, I have an empty line at the same indentation level as the code around it.

The indentation is only retained if something has been typed (including if it was subsequently deleted). It shouldn't stick around with a double tap of enter. At least it doesn't for me, maybe that's a setting.

That said, it can be annoying when it reports the indent of the current line though. I've gotten used to that from TSLint (which works the same way), but it would be cool if we could ignore the warning for the current line. That would have to be done on the PowerShellEditorServices side though, because we don't report cursor status to PSSA.

would it be better to turn this rule not on by default for the moment

👍

[bergmeister]

Ok, I created a PR in the PSES repo to not have the rule enabled by default for the moment as a quick solution

[stetan]

Yes, this was quite a surprise when, all of a sudden, I saw hundreds of alerts in my code. I'm amazed no one picked this up before it was pulled into the main code, as every code editor adds tabs/spaces to indent blank lines to the level of the preceding code as a default setting.

[TylerLeonhardt]

@SeeminglyScience filtering out the PSSA warnings that contain the cursor position shouldn't be too hard to add.

I don't think I've seen any other linters do something like that but it makes sense to me.

[nschonni]

Not something I'd use, but here is the setting from ESLint https://eslint.org/docs/rules/no-trailing-spaces#options