fish-shell/share/functions/alias.fish
Kurtis Rader f2c8e73891 add more alias unit tests
A recent regression to the `alias` command points out the need for more
unit tests of its behavior. I also decided to use it as an opportunity
to normalize the output of just `alias` to list aliases.
2017-07-15 17:36:36 -07:00

73 lines
2.5 KiB
Fish

function alias --description 'Creates a function wrapping a command'
set -l options 'h/help'
argparse -n alias --max-args=2 $options -- $argv
or return
if set -q _flag_help
__fish_print_help alias
return 0
end
set -l name
set -l body
set -l prefix
set -l first_word
set -l wrapped_cmd
if not set -q argv[1]
# Print the known aliases.
for func in (functions -n)
set -l output (functions $func | string match -r -- "^function .* --description 'alias (.*)'")
if set -q output[2]
set output (string replace -r '^'$func'[= ]' '' -- $output[2])
echo alias $func (string escape -- $output[1])
end
end
return 0
else if not set -q argv[2]
# Alias definition of the form "name=value".
set -l tmp (string split -m 1 "=" -- $argv) ""
set name $tmp[1]
set body $tmp[2]
else
# Alias definition of the form "name value".
set name $argv[1]
set body $argv[2]
end
# sanity check
if test -z "$name"
printf ( _ "%s: Name cannot be empty\n") alias
return 1
else if test -z "$body"
printf ( _ "%s: Body cannot be empty\n") alias
return 1
end
# Extract the first command from the body. This is supposed to replace all non-escaped (i.e.
# preceded by an odd number of `\`) spaces with a newline so it splits on them. See issue #2220
# for why the following borderline incomprehensible code exists.
set -l tmp (string replace -ra "([^\\\ ])((\\\\\\\)*) " '$1\n' $body)
set first_word (string trim $tmp[1])
# If the user does something like `alias x 'foo; bar'` we need to strip the semicolon.
set wrapped_cmd (string trim -c ';' $first_word)
if set -q tmp[2]
set body $tmp[2..-1]
else
set body
end
# Prevent the alias from immediately running into an infinite recursion if
# $body starts with the same command as $name.
if test $wrapped_cmd = $name
if contains $name (builtin --names)
set prefix builtin
else
set prefix command
end
end
set -l cmd_string (string escape "alias $argv")
set wrapped_cmd (string escape $wrapped_cmd)
echo "function $name --wraps $wrapped_cmd --description $cmd_string; $prefix $first_word $body \$argv; end" | source
#echo "function $name --wraps $wrapped_cmd --description $cmd_string; $prefix $first_word $body \$argv; end"
end