plugin/git: add gitsigns nvim plugin

default.nix

@@ -16,6 +16,7 @@ let
 
   plugins = callPlugins [
     ./plugins/syntax
+    ./plugins/git
     ./plugins/explorer
     (import ./plugins/theme {
       inherit enableBarBar enableDevIcons;

plugins/git/default.nix

@@ -0,0 +1,7 @@
+{ gitsigns-nvim, ... }:
+
+{
+  luaConfig = builtins.readFile ./gitsigns-nvim.lua;
+
+  plugins = [ gitsigns-nvim ];
+}

plugins/git/gitsigns-nvim.lua

@@ -0,0 +1,52 @@
+function on_attach(bufnr)
+	local gs = package.loaded.gitsigns
+
+	local function map(mode, l, r, opts)
+		opts = opts or {}
+		opts.buffer = bufnr
+		vim.keymap.set(mode, l, r, opts)
+	end
+
+	-- Navigation
+	map("n", "]h", function()
+		if vim.wo.diff then
+			return "]h"
+		end
+		vim.schedule(function()
+			gs.next_hunk()
+		end)
+		return "<Ignore>"
+	end, { expr = true })
+
+	map("n", "[h", function()
+		if vim.wo.diff then
+			return "[h"
+		end
+		vim.schedule(function()
+			gs.prev_hunk()
+		end)
+		return "<Ignore>"
+	end, { expr = true })
+
+	-- Actions
+	map({ "n", "v" }, "<leader>gs", ":Gitsigns stage_hunk<CR>")
+	map({ "n", "v" }, "<leader>gr", ":Gitsigns reset_hunk<CR>")
+	map("n", "<leader>gu", gs.undo_stage_hunk)
+	map("n", "<leader>gp", gs.preview_hunk)
+	map("n", "<leader>gb", function()
+		gs.blame_line({ full = true })
+	end)
+	map("n", "<leader>gtb", gs.toggle_current_line_blame)
+	map("n", "<leader>gd", gs.diffthis)
+	map("n", "<leader>gD", function()
+		gs.diffthis("~")
+	end)
+
+	-- Text object
+	map({ "o", "x" }, "ih", ":<C-U>Gitsigns select_hunk<CR>")
+end
+
+-- See: https://github.com/lewis6991/gitsigns.nvim
+require("gitsigns").setup({
+	on_attach = on_attach,
+})