neovim: Add coc support (#2154)

This adds two new options: 'programs.neovim.coc.{enable,settings}`.

These settings offer a simple interface over `xdg.configFile."nvim/coc-settings.json`,
using the standard Nix' syntax instead of a multiline string.

tests/modules/programs/neovim/coc-config.expected

@@ -0,0 +1,3 @@
+{
+  "foo": "bar"
+}

tests/modules/programs/neovim/coc-config.nix

@@ -0,0 +1,27 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  config = {
+    programs.neovim = {
+      enable = true;
+      coc = {
+        enable = true;
+        settings = {
+          # my variable
+          foo = "bar";
+        };
+      };
+    };
+
+    nmt.script = ''
+      cocSettings="$TESTED/home-files/.config/nvim/coc-settings.json"
+      cocSettingsNormalized="$(normalizeStorePaths "$cocSettings")"
+
+      assertFileExists "$cocSettings"
+      assertFileContent "$cocSettingsNormalized" "${./coc-config.expected}"
+    '';
+  };
+}
+

tests/modules/programs/neovim/default.nix

@@ -1,5 +1,6 @@
 {
   neovim-plugin-config = ./plugin-config.nix;
+  neovim-coc-config = ./coc-config.nix;
   # waiting for a nixpkgs patch
   # neovim-no-init = ./no-init.nix;
 }