Add purs-tidy formatter (#182)

Hello!

I would like to add support for `purs-tidy` - PureScript formatter. 

Best wishes
alternateved

CHANGELOG.md

@@ -6,11 +6,17 @@ The format is based on [Keep a Changelog].
 ## Unreleased
 ### Enhancements
 * Prettier is now enabled in `svelte-mode`.
+
 ### Bugs fixed
 * `ktlint` would emit log messages into its stdout when formatting,
   and these would get spliced into the source file. This has been fixed
   by suppressing all logs from `ktlint`.
 
+### Formatters
+* [purs-tidy](https://github.com/natefaubion/purescript-tidy) for PureScript ([#182]).
+
+[#182]: https://github.com/radian-software/apheleia/pull/182
+
 ## 3.2 (released 2023-02-25)
 ### Features
 * You can use `apheleia-inhibit` as a file-local variable to disable

apheleia-formatters.el

@@ -153,6 +153,7 @@ Otherwise return the extension only."
      . (npx "prettier" "--stdin-filepath" filepath "--parser=typescript"))
     (prettier-yaml
      . (npx "prettier" "--stdin-filepath" filepath "--parser=yaml"))
+    (purs-tidy . (npx "purs-tidy" "format"))
     (shfmt . ("shfmt" "-i" "4"))
     (stylua . ("stylua" "-"))
     (rustfmt . ("rustfmt" "--quiet" "--emit" "stdout"))
@@ -265,6 +266,7 @@ rather than using this system."
     (lua-mode . stylua)
     (lisp-mode . lisp-indent)
     (nix-mode . nixfmt)
+    (purescript-mode . purs-tidy)
     (python-mode . black)
     (python-ts-mode . black)
     (ruby-mode . prettier-ruby)

test/formatters/installers/purs-tidy.bash

@@ -0,0 +1 @@
+npm install -g purs-tidy

test/formatters/samplecode/purs-tidy/in.purs

@@ -0,0 +1,7 @@
+module Foo where     
+baz ::Array(String)
+ -> Int->Boolean->Int            
+baz _ n        
+ = case _ of
+   true-> 20 +1
+   false -> if n> 0 then 3-(-2)else 0          

test/formatters/samplecode/purs-tidy/out.purs

@@ -0,0 +1,10 @@
+module Foo where
+
+baz
+  :: Array (String)
+  -> Int
+  -> Boolean
+  -> Int
+baz _ n = case _ of
+  true -> 20 + 1
+  false -> if n > 0 then 3 - (-2) else 0