Conditional alias not working

[chtenb]

Describe the bug

❯ alias test = if (sys).host.name == "Windows" { bash 'C:\Program Files\nodejs\npm' } else { ^npm }

~
❯ test -v
Error: nu::parser::parse_mismatch (link)

  × Parse mismatch during operation.
   ╭─[entry #31:1:1]
 1 │ test -v
   ·      ─┬
   ·       ╰── expected operator
   ╰────

How to reproduce

See above

Expected behavior

I would expect that the alias would seemlessly operate as either of the conditional branches

Screenshots

No response

Configuration

key	value
version	0.63.0
branch
commit_hash	06cf3fa5ad8c8b1d1351c81ccea59a1f8d588dc9
build_os	windows-x86_64
build_target	x86_64-pc-windows-msvc
rust_version	rustc 1.61.0 (fe5b13d68 2022-05-18)
rust_channel	stable-x86_64-pc-windows-msvc
cargo_version	cargo 1.61.0 (a028ae42f 2022-04-29)
pkg_version	0.63.0
build_time	2022-05-25 01:15:47 +00:00
build_rust_channel	release
features	database, dataframe, default, trash, which, zip
installed_plugins

Additional context

No response

[fdncred]

I'm not sure it makes a difference unless there's a problem with sys but you could try $nu.os-info.name to check the os. It should be many times faster. It's also a little weird to me that you're calling bash on windows if it's windows. Another solution is just to put the nodejs folder in your PATH on windows, then you should just be able to npm.

[chtenb]

The reason for this workaround is because npm.cmd gives problems on my system, while the bash script works fine. But it is beside the point of this issue, which is about nu giving a parse error on an alias, which is something I do not understand.

[fdncred]

what happens if you put the part on the right side of the = in parentheses?

[chtenb]

@fdncred The same behavior.

[fdncred]

I got a little closer with this alias test = (if $nu.os-info.name == windows { bash '/mnt/c/Program Files/nodejs/npm' } else { ^npm }) but the syntax highlighter is still seeing -v as valid when i do test -v.

[vereym]

Hey it seems I've run into a problem that could be related.

~
❯ alias doom = if (sys).host.hostname == bloodsong {
:::        ^/home/antoni/.emacs.d/bin/doom
:::     } else {
:::        ^/home/antoni/doomemacs/bin/doom
:::     }

~
❯ doom help
Error: nu::parser::extra_positional (link)

  × Extra positional argument.
   ╭─[entry #8:1:1]
 1 │ doom help
   ·      ──┬─
   ·        ╰── extra positional argument
   ╰────
  help: Usage: if <cond> <then_block> (else <else_expression>)

I think this comes from aliases not being evaluated when they are aliased. Don't know if this is intended behaviour.