Add trim_file command and trim_file_on_save configuration option

[poliorcetics]

Describe your feature request

I know there is an trim_selection command but using it breaks the current selection, which is a not very helpful. It's also not very practical to do it for each opened file when ending a somewhat long session.

[poliorcetics]

This would maybe need an additional config option to not do it for heavy files, since trimming could be quite long on files of 100k lines ? Even if there is no trimming to be done, each line must be checked individually (though that should be parallel once the initial reading is done).

[poliorcetics]

Add-on: maybe a default option + a per language one since markdown uses "two spaces at end of line" as code for "insert visible line break here" but I don't know of any other commonly used language that does something like this

[EpocSquadron]

It's worth noting that trim_selection is intended to literally change the selections to exclude whitespace from their ends. It does not actually remove the whitespace from the document.

Currently, we rely on the LSP implementation to format on document save, which will often include trimming whitespace from the end of lines. If the LSP is not present or doesn't implement formatting, then you are currently stuck doing it manually. There is discussion of what to do about this elsewhere but I'm on mobile, may find it later and comment.

In the meantime, you can select the entire document (%), then pipe to a formatter on the command line (|prettier<enter> for example).

[EpocSquadron]

#1396 would somewhat alleviate this issue.

[Omnikar]

Describe your feature request

I know there is an trim_selection command but using it breaks the current selection, which is a not very helpful. It's also not very practical to do it for each opened file when ending a somewhat long session.

As for applying some operation to all the files in a long session, macros can probably help automate that.

[Omnikar]

Here's a macro that should trim trailing whitespace from the end of all lines in the current buffer, save it, then close it. If you yank the macro into the @ register, you should be able to just hold q (or type a large enough number followed by q) to apply the macro to every open buffer.

%<A-s>Xs\s+\n<ret>vhvd:w<ret>:bc<ret>

[poliorcetics]

#1396 would somewhat alleviate this issue.

I don't like this solution much; it forces users to have a default language server on every new install of helix and to wait for it to spin up to quickly trim a file that failed an editor-config check.

[paveloom]

Using the current version from the master branch, you can do the following:

# ~/.config/helix/config.toml
# <...>
[keys.normal]
C-s = [
    "save_selection",
    "select_all",
    # Delete trailing whitespace from end of each line
    ":pipe sed 's/[ \t]*$//'",
    # Delete trailing blank lines (including whitespace) from end of the buffer
    ":pipe awk '/^\\s*$/ {b=b $0 \"\\n\"; next;} {printf \"%s\",b; b=\"\"; print;}'",
    "collapse_selection",
    "jump_backward",
    "commit_undo_checkpoint",
    ":write",
]
# <...>

Current issues:

• the commit_undo_checkpoint command is a workaround (Using :write after any command that produces changes introduces a phantom change #2192);
• if you left the cursor in the targeted whitespace area, the program may crash on the backward jump (Occasional crash when jumping to previous location #1238).

References:

• https://stackoverflow.com/a/61516740
• http://sed.sourceforge.net/sed1line.txt

[vasylnakvasiuk]

Would be nice to have similar to VS Code flags:

[rcorre]

Note that if you have git installed, you can use git stripspace as a language formatter:

[[language]]
name = "gdscript"
language-server = { command = "nc", args = ["localhost", "6005"], language-id = "gdscript" }
formatter = { command = "git", args = ["stripspace"] }

As noted by @DannyJJK, this has some other consequences. Use the sed suggestions elsewhere in this thread.

[DannyJJK]

Note that if you have git installed, you can use git stripspace as a language formatter:

[[language]]
name = "gdscript"
language-server = { command = "nc", args = ["localhost", "6005"], language-id = "gdscript" }
formatter = { command = "git", args = ["stripspace"] }

I'm not sure if that's a good idea, the documentation for this says:

NOTE: This is intended for cleaning metadata, prefer the --whitespace=fix mode of git-apply[1] for correcting whitespace of patches or files in the repository.

https://git-scm.com/docs/git-stripspace#_description

[Kurt-Shiwz]

Using the current version from the master branch, you can do the following:

# ~/.config/helix/config.toml
# <...>
[keys.normal]
C-s = [
    "save_selection",
    "select_all",
    # Delete trailing whitespace from end of each line
    ":pipe sed 's/[ \t]*$//'",
    # Delete trailing blank lines (including whitespace) from end of the buffer
    ":pipe awk '/^\\s*$/ {b=b $0 \"\\n\"; next;} {printf \"%s\",b; b=\"\"; print;}'",
    "collapse_selection",
    "jump_backward",
    "commit_undo_checkpoint",
    ":write",
]
# <...>

Current issues:

• the commit_undo_checkpoint command is a workaround (Using :write after any command that produces changes introduces a phantom change #2192);
• if you left the cursor in the targeted whitespace area, the program may crash on the backward jump (Occasional crash when jumping to previous location #1238).

References:

• https://stackoverflow.com/a/61516740
• http://sed.sourceforge.net/sed1line.txt

thx, i try to keep the file has new line on end of file, it work.

C-s = [
    "save_selection",
    "select_all",
    # Delete trailing whitespace from end of each line
    ":pipe sed 's/[ \t]*$//'",
    # Delete trailing blank lines (including whitespace) from end of the buffer
    ":pipe awk '/^\\s*$/ {b=b $0 \"\\n\"; next;} {printf \"%s\",b; b=\"\"; print;}'",
    "collapse_selection",
    "goto_last_line",
    "add_newline_below",
    "commit_undo_checkpoint",
    ":write",
]

I want know is there some other way to do that?

[rcorre]

FWIW, if you use sed as a formatter in languages.toml, you don't need all the selection/checkpoint stuff:

formatter = { command = "sed", args = ["s/[ \t]*$//"] }

[milanglacier]

FYI, if you don't want to exit file after trimming white spaces, but you want to keep editing the files, you may find the following command to be helpful as it keeps the original cursor position:

"space" = { "m" = [ "save_selection", "select_all", ":pipe sed 's/[[:space:]]*$//'", "collapse_selection", "jump_backward", "flip_selections" ] }

The trick here is you need to use jump_backward with flip_selections together to restore the original cursor position.