Strip leading spaces after line continuation

[casey]

Make line continuations strip leading spaces on the next line.

This changes what is passed to the shell, so this is a breaking change.
However, I don't think that this will break any recipes.

[casey]

I am doing a Janus run to try to figure out if there are recipes that are likely to be broken. What I'll be looking for are line continuations without a space before the slash, and with leading whitespace on the next line. Like this:

foo:
  echo bar\
    baz

This currently runs echo bar baz, but after the change would run echo barbaz.

[casey]

I could only find one justfile on github that seems to be affected, and opened a PR with a fix.

[camerondavison]

Just my two cents. After this broke my justfiles (they are private so no way you would have known) I found this ticket.

I think that it would have been nice to make this work like Make in that it stripped all the spaces equal to the indent. I think that is what happens for the shebang polyglot code.

[casey]

Just my two cents. After this broke my justfiles (they are private so no way you would have known) I found this ticket.

Ahh, sorry this broke your justfiles. Did they have slashes without spaces before them? Like this:

foo:
  echo bar\
   baz

I think I assumed that having no space before line continuation slashes is less common than it actually is.

I think that it would have been nice to make this work like Make in that it stripped all the spaces equal to the indent. I think that is what happens for the shebang polyglot code.

Do you mean that in this justfile:

foo:
  echo bar \
   baz

The first line of foo would be:

echo bar baz

I.e. two spaces between bar and baz?

[camerondavison]

Thanks for reaching out. Yes. This is my example
Makefile

echo:
	set -x && echo test\
	this
echo2:
	set -x && echo test\
	 this

❯ make echo
set -x && echo test\
	this
+ echo testthis
testthis

❯ make echo2
set -x && echo test\
	 this
+ echo test this
test this

and justfile just v0.6.1

echo:
    set -x && echo test\
     this
echo2:
    #!/bin/bash
    set -x && echo test\
     this

❯ just echo
set -x && echo testthis
+ echo testthis
testthis

❯ just echo2
+ echo test this
test this

[casey]

Thanks for the examples. Is there a reason that you prefer not stripping leading spaces from the line after a line continuation?

My thinking was that you often want to indent the line after a line continuation, to visually distinguish it, but you don't necessarily want to include the whitespace, especially if there is a space before the slash.

In this example, if you're using two space indents, you probably don't want two spaces between foo and bar:

echo:
  set -x && echo foo\
    bar

If you like putting a space before the slash, as in this example, you can't indent the next line or else you'll get extra spaces:

echo:
  set -x && echo foo \
  bar

[camerondavison]

I can for sure change my behavior. I appreciate the conversation. I think that I never liked putting the space before the slash because then i would not be able to indent it in make without adding an extra space. So I guess the change allows one to put the space before the slash without adding extra spaces. I just got used to putting the slash at the end because of that.

[casey]

Thanks for the background, I like the new behavior, although it's definitely unfortunate that I introduced an incompatibility with make :/

[camerondavison]

Makes sense. Is there a thought to do the same for the shebang polyglot syntax?

[casey]

Shebang recipes should be safe! Shebang recipes are extracted without doing any processing aside from stripping indentation, so any escaping is done by the underlying interpreter, whatever that may be.