Teach alias about wrap argument injection

Update the alias function to pass arguments to 'wraps'. For example
alias gco='git checkout' now works like it ought to.

CHANGELOG.md

@@ -41,7 +41,7 @@ This section is for changes merged to the `major` branch that are not also merge
 - Tildes in file names are now properly escaped in completions (#2274)
 - A pipe at the end of a line now allows the job to continue on the next line (#1285)
 - The names `argparse`, `read`, `set`, `status`, `test` and `[` are now reserved and not allowed as function names. This prevents users unintentionally breaking stuff (#3000).
-- Wrapping completions (from `complete -w` or `function -w`) can now inject arguments. For example, `complete gco -w 'git checkout'` now works properly (#1976).
+- Wrapping completions (from `complete -w` or `function -w`) can now inject arguments. For example, `complete gco -w 'git checkout'` now works properly (#1976). The `alias` function has been updated to respect this behavior.
 
 ## Other significant changes
 - Command substitution output is now limited to 10 MB by default (#3822).

share/functions/alias.fish

@@ -50,7 +50,7 @@ function alias --description 'Creates a function wrapping a command'
     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)
+    set base_command (string trim -c ';' $first_word)
     if set -q tmp[2]
         set body $tmp[2..-1]
     else
@@ -59,7 +59,7 @@ function alias --description 'Creates a function wrapping a command'
 
     # 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 test $base_command = $name
         if contains $name (builtin --names)
             set prefix builtin
         else
@@ -67,7 +67,7 @@ function alias --description 'Creates a function wrapping a command'
         end
     end
     set -l cmd_string (string escape "alias $argv")
-    set wrapped_cmd (string escape $wrapped_cmd)
+    set wrapped_cmd (string join ' ' $first_word $body | string escape)
     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

tests/complete.err

@@ -1,3 +1,6 @@
 
 ####################
 # Completion Wrappers
+
+####################
+# Alias Completions

tests/complete.in

@@ -1,5 +1,7 @@
 logmsg Completion Wrappers
 
+function complete_test_alpha1; echo $argv; end
+
 complete -c complete_test_alpha1 --no-files -a '(commandline)'
 complete -c complete_test_alpha2 --no-files -w 'complete_test_alpha1 extra1'
 complete -c complete_test_alpha3 --no-files -w 'complete_test_alpha2 extra2'
@@ -7,3 +9,13 @@ complete -c complete_test_alpha3 --no-files -w 'complete_test_alpha2 extra2'
 complete -C'complete_test_alpha1 arg1 '
 complete -C'complete_test_alpha2 arg2 '
 complete -C'complete_test_alpha3 arg3 '
+
+logmsg Alias Completions
+
+alias myalias1 'complete_test_alpha1 arg1'
+alias myalias2='complete_test_alpha1 arg2'
+
+myalias1 call1
+myalias2 call2
+complete -C'myalias1 call3 '
+complete -C'myalias2 call3 '

tests/complete.out

@@ -4,3 +4,10 @@
 complete_test_alpha1 arg1 
 complete_test_alpha1 extra1 arg2 
 complete_test_alpha1 extra1 extra2 arg3 
+
+####################
+# Alias Completions
+arg1 call1
+arg2 call2
+complete_test_alpha1 arg1 call3 
+complete_test_alpha1 arg2 call3