home: vim: lsp: rely on 'bashls' formatting

I finally figured out why I was getting the wrong indentation, turns out
it was an issue in `lsp-format.nvim`. With that fixed/worked around, I
can now rely completely on `bash-language-server` for formatting.

I'll also rely on `shfmt` automatically detecting the type of file, as
(Neo)Vim cannot be made to reliably set `ft=bash` for Bash scripts and
`ft=sh` for POSIX shell.

Finally, I removed spaces after redirections, I've now come around to
liking the default (no spaces) better.

modules/home/vim/plugin/settings/lspconfig.lua

@@ -74,6 +74,16 @@ if utils.is_executable("bash-language-server") then
         filetypes = { "bash", "sh", "zsh" },
         capabilities = capabilities,
         on_attach = lsp.on_attach,
+        settings = {
+            bashIde = {
+                shfmt = {
+                    -- Simplify the code
+                    simplifyCode = true,
+                    -- Indent switch cases
+                    caseIndent = true,
+                },
+            },
+        },
     })
 end
 

modules/home/vim/plugin/settings/null-ls.lua

@@ -46,29 +46,3 @@ null_ls.register({
         condition = utils.is_executable_condition("isort"),
     }),
 })
-
--- Shell (non-POSIX)
-null_ls.register({
-    null_ls.builtins.formatting.shfmt.with({
-        -- Indent with 4 spaces, simplify the code, indent switch cases,
-        -- add space after redirection, use bash dialect
-        extra_args = { "-i", "4", "-s", "-ci", "-sr", "-ln", "bash" },
-        -- Restrict to bash and zsh
-        filetypes = { "bash", "zsh" },
-        -- Only used if available
-        condition = utils.is_executable_condition("shfmt"),
-    }),
-})
-
--- Shell (POSIX)
-null_ls.register({
-    null_ls.builtins.formatting.shfmt.with({
-        -- Indent with 4 spaces, simplify the code, indent switch cases,
-        -- add space after redirection, use POSIX
-        extra_args = { "-i", "4", "-s", "-ci", "-sr", "-ln", "posix" },
-        -- Restrict to POSIX sh
-        filetypes = { "sh" },
-        -- Only used if available
-        condition = utils.is_executable_condition("shfmt"),
-    }),
-})

overlays/lsp-format-nvim-indentation/default.nix

@@ -0,0 +1,4 @@
+self: prev:
+{
+  vimPlugins = prev.vimPlugins.extend (self.callPackage ./generated.nix { });
+}

overlays/lsp-format-nvim-indentation/generated.nix

@@ -0,0 +1,14 @@
+{ fetchpatch, ... }:
+
+_final: prev: {
+  lsp-format-nvim = prev.lsp-format-nvim.overrideAttrs (oa: {
+    patches = (oa.patches or [ ]) ++ [
+      # https://github.com/lukas-reineke/lsp-format.nvim/issues/94
+      (fetchpatch {
+        name = "use-effective-indentation";
+        url = "https://github.com/liskin/lsp-format.nvim/commit/3757ac443bdf5bd166673833794553229ee8d939.patch";
+        hash = "sha256-Dv+TvXrU/IrrPxz2MSPbLmRxch+qkHbI3AyFMj/ssDk=";
+      })
+    ];
+  });
+}