ncmpcpp: Allow str type values for mpdMusicDir option

The default value of `programs.ncmpcpp.mpdMusicDir` is taken from
`services.mpd.musicDirectory` if the mpd module is enabled, which has
type `either path str`. `programs.ncmpcpp.mpdMusicDir` did not accept
`str` values, though, so an error was raised when the default value was
used and `services.mpd.musicDirectory` was set to a value of type `str`.

This commit changes the type of `programs.ncmpcpp.mpdMusicDir` to also
accept `str` to reflect the type of `services.mpd.musicDirectory`.

Fixes nix-community#3560

modules/programs/ncmpcpp.nix

@@ -62,7 +62,7 @@ in {
     };
 
     mpdMusicDir = mkOption {
-      type = types.nullOr types.path;
+      type = with types; nullOr (coercedTo path toString str);
       default = let mpdCfg = config.services.mpd;
       in if pkgs.stdenv.hostPlatform.isLinux && mpdCfg.enable then
         mpdCfg.musicDirectory
@@ -123,7 +123,7 @@ in {
     xdg.configFile = {
       "ncmpcpp/config" = let
         settings = cfg.settings // optionalAttrs (cfg.mpdMusicDir != null) {
-          mpd_music_dir = toString cfg.mpdMusicDir;
+          mpd_music_dir = cfg.mpdMusicDir;
         };
       in mkIf (settings != { }) { text = renderSettings settings + "\n"; };
 

tests/modules/programs/ncmpcpp-linux/default.nix

@@ -1 +1,4 @@
-{ ncmpcpp-use-mpd-config = ./ncmpcpp-use-mpd-config.nix; }
+{
+  ncmpcpp-use-mpd-config = ./ncmpcpp-use-mpd-config.nix;
+  ncmpcpp-issue-3560 = ./ncmpcpp-issue-3560.nix;
+}

tests/modules/programs/ncmpcpp-linux/ncmpcpp-issue-3560-expected-config

@@ -0,0 +1 @@
+mpd_music_dir=~/music

tests/modules/programs/ncmpcpp-linux/ncmpcpp-issue-3560.nix

@@ -0,0 +1,25 @@
+{ pkgs, ... }:
+
+{
+  config = {
+    # Minimal config reproducing
+    # https://github.com/nix-community/home-manager/issues/3560
+    programs.ncmpcpp.enable = true;
+
+    services.mpd.enable = true;
+    services.mpd.musicDirectory = "~/music";
+
+    test.stubs = {
+      ncmpcpp = { };
+      mpd = { };
+    };
+
+    nmt.script = ''
+      assertFileContent \
+        home-files/.config/ncmpcpp/config \
+        ${./ncmpcpp-issue-3560-expected-config}
+
+      assertPathNotExists home-files/.config/ncmpcpp/bindings
+    '';
+  };
+}