ci: add linting (#108)

###### Description of changes

###### Things done

- [x] Tested, as applicable:
  - [ ] Manually
  - [x] Added lints
- [x] Updated
[CHANGELOG.md](https://github.com/MrcJkb/haskell-tools.nvim/blob/master/CHANGELOG.md)
(if applicable).
- [x] Fits
[CONTRIBUTING.md](https://github.com/MrcJkb/haskell-tools.nvim/blob/master/CONTRIBUTING.md)

.luacheckrc

@@ -0,0 +1,10 @@
+ignore = {
+  "631",    -- max_line_length
+  "122",    -- read-only field of global variable
+}
+read_globals = {
+  "vim",
+  "describe",
+  "it",
+  "assert"
+}

.luarc.json

@@ -0,0 +1,11 @@
+{
+    "$schema": "https://raw.githubusercontent.com/sumneko/vscode-lua/master/setting/schema.json",
+    "Lua.workspace.checkThirdParty": false,
+    "Lua.diagnostics.globals": [
+      "vim",
+      "describe",
+      "it",
+      "assert"
+    ],
+    "Lua.runtime.version": "LuaJIT"
+}

CONTRIBUTING.md

@@ -10,9 +10,11 @@ This project uses [Conventional Commits](https://www.conventionalcommits.org/en/
 
 ## Development
 
-I use [`nix`](https://nixos.org/download.html#download-nix) for development and testing.
+I use
 
-Formatting is done with [`stylua`](https://github.com/JohnnyMorganz/StyLua).
+* [`nix`](https://nixos.org/download.html#download-nix) for development and testing.
+* [`stylua`](https://github.com/JohnnyMorganz/StyLua) for formatting.
+* [`luacheck`](https://github.com/mpeterv/luacheck) and [`sumneko-lua-language-server`](https://github.com/sumneko/lua-language-server/wiki/Diagnosis-Report#create-a-report) for linting.
 
 To enter a development shell:
 

doc/haskell-tools.txt

@@ -223,6 +223,11 @@ repl.setup()                                                        *repl.setup*
      Set up this module. Called by the haskell-tools setup.
 
 
+repl.toggle()                                                      *repl.toggle*
+     Toggle a GHCi REPL
+     @param filepath string?: optional file path
+
+
 repl.paste()                                                        *repl.paste*
      Paste from register `reg` to the REPL
      @param reg string?: register (defaults to '"')

flake.nix

@@ -67,6 +67,7 @@
     test-overlay = import ./nix/test-overlay.nix {
       inherit
         (inputs)
+        self
         packer-nvim
         plenary-nvim
         telescope-nvim
@@ -105,6 +106,7 @@
           zlib
           alejandra
           stylua
+          lua51Packages.luacheck
         ];
       };
   in {
@@ -139,6 +141,7 @@
       formatting = pre-commit-check-for system;
       inherit
         (checkPkgs)
+        lints
         haskell-tools-test
         haskell-tools-test-no-telescope
         haskell-tools-test-no-telescope-with-hoogle

lua/haskell-tools/config.lua

@@ -137,7 +137,7 @@ config.defaults = {
   ---@type HaskellLspClientOpts
   hls = {
     debug = false,
-    on_attach = function(...) end,
+    on_attach = function(_, _) end,
     cmd = { 'haskell-language-server-wrapper', '--lsp', '--logfile', config.hls_log },
     filetypes = { 'haskell', 'lhaskell', 'cabal', 'cabalproject' },
     capabilities = capabilities,

lua/haskell-tools/hoogle.lua

@@ -11,7 +11,7 @@ local lsp_util = vim.lsp.util
 ---@field hoogle_signature function Hoogle search for a symbol's type signature
 ---@field setup function
 
-local handler = function(...) end
+local handler = function(_, _) end
 
 ---@type HaskellToolsHoogle
 local hoogle = {}

lua/haskell-tools/repl.lua

@@ -124,7 +124,7 @@ end
 --- Set up this module. Called by the haskell-tools setup.
 function repl.setup()
   local opts = ht.config.options.tools.repl
-  local handler = {}
+  local handler
   if opts.handler == 'toggleterm' then
     ht.log.info('handler = toggleterm')
     local toggleterm = require('haskell-tools.repl.toggleterm')
@@ -139,7 +139,9 @@ function repl.setup()
 
   --- Toggle a GHCi REPL
   --- @param filepath string?: optional file path
-  repl.toggle = handler.toggle
+  function repl.toggle(filepath, ...)
+    handler.toggle(filepath, ...)
+  end
 
   --- Quit the REPL
   repl.quit = handler.quit

lua/haskell-tools/repl/builtin.lua

@@ -194,9 +194,8 @@ function builtin.setup(mk_repl_cmd, options)
   ht.log.debug { 'repl.builtin setup', options }
   builtin.go_back = options.auto_focus ~= true
   ---@param filepath string path of the file to load into the repl
-  ---@param opts table?
-  function builtin.toggle(filepath, opts)
-    opts = opts or vim.empty_dict()
+  ---@param _ table?
+  function builtin.toggle(filepath, _)
     local cur_win = vim.api.nvim_get_current_win()
     if filepath and not vim.endswith(filepath, '.hs') then
       local err_msg = 'haskell-tools.repl.builtin: Not a Haskell file: ' .. filepath

nix/test-overlay.nix

@@ -1,4 +1,5 @@
 {
+  self,
   packer-nvim,
   plenary-nvim,
   nvim-lspconfig,
@@ -8,6 +9,48 @@
 with final.lib;
 with final.lib.strings;
 with final.stdenv; let
+  lints = mkDerivation {
+    name = "haskell-tools-lints";
+
+    src = self;
+
+    phases = [
+      "unpackPhase"
+      "buildPhase"
+      "checkPhase"
+    ];
+
+    doCheck = true;
+
+    buildInputs = with final; [
+      lua51Packages.luacheck
+      sumneko-lua-language-server
+    ];
+
+    buildPhase = ''
+      mkdir -p $out
+      cp -r lua $out/lua
+      cp -r tests $out/tests
+      cp .luacheckrc $out
+      cp .luarc.json $out
+    '';
+
+    checkPhase = ''
+      export HOME=$(realpath .)
+      cd $out
+      luacheck lua
+      luacheck tests
+      lua-language-server --check "$out/lua" \
+        --configpath "$out/.luarc.json" \
+        --logpath "$out" \
+        --checklevel="Warning"
+      if [[ -f $out/check.json ]]; then
+        cat $out/check.json
+        exit 1
+      fi
+    '';
+  };
+
   nvim-nightly = final.neovim-nightly;
 
   mkPlenaryTest = {
@@ -53,6 +96,8 @@ with final.stdenv; let
       '';
     };
 in {
+  inherit lints;
+
   haskell-tools-test = mkPlenaryTest {name = "haskell-tools";};
 
   haskell-tools-test-no-telescope = mkPlenaryTest {