Refresh zcompdump cache in each home-manager activation (#857)

* Extract zcompdump path with zsh only variable

* Remove ZCOMPDUMP_CACHE in each home-manager activation

Without this, no completion changes after packages changes, it makes much confusion

* Fix to handle cache

* As same as in zsh code

home-manager/zsh.nix

@@ -6,6 +6,10 @@
   ...
 }:
 
+let
+  ZCOMPDUMP_CACHE_DIR = "${config.xdg.cacheHome}/zsh";
+  ZCOMPDUMP_CACHE_PATH = "${ZCOMPDUMP_CACHE_DIR}/zcompdump-${pkgs.zsh.version}";
+in
 {
   services.gpg-agent.enableZshIntegration = true;
   programs.starship.enableZshIntegration = true;
@@ -15,6 +19,14 @@
   # Avoid nested zellij in host and remote login as container
   programs.zellij.enableZshIntegration = false;
 
+  home.activation.refreshZcompdumpCache = config.lib.dag.entryAnywhere ''
+    if [[ -v oldGenPath ]]; then
+      run ${lib.getBin pkgs.coreutils}/bin/mkdir -p '${ZCOMPDUMP_CACHE_DIR}'
+      run ${lib.getExe pkgs.zsh} --interactive -c 'compinit -d "${ZCOMPDUMP_CACHE_PATH}"'
+      run ${lib.getBin pkgs.coreutils}/bin/touch '${ZCOMPDUMP_CACHE_PATH}' # Ensure to update timestamp
+    fi
+  '';
+
   # https://nixos.wiki/wiki/Zsh
   # https://zsh.sourceforge.io/Doc/Release/Options.html
   # https://github.com/nix-community/home-manager/blob/release-24.05/modules/programs/zsh.nix
@@ -28,6 +40,8 @@
     dotDir = ".config/zsh";
 
     localVariables = {
+      inherit ZCOMPDUMP_CACHE_DIR ZCOMPDUMP_CACHE_PATH;
+
       # This is a minimum note for home-manager dead case such as https://github.com/kachick/dotfiles/issues/680#issuecomment-2353820508
       PROMPT = ''
         %~ %? %#
@@ -127,19 +141,19 @@
       # speed - https://gist.github.com/ctechols/ca1035271ad134841284
       # both - https://github.com/kachick/dotfiles/pull/155
       _compinit_with_interval() {
-        local -r dump_dir="${config.xdg.cacheHome}/zsh"
-        local -r dump_path="$dump_dir/zcompdump-$ZSH_VERSION"
         # seconds * minutes * hours
         local -r threshold="$((60 * 60 * 3))"
 
-        if [ -e "$dump_path" ] && [ "$(_elapsed_seconds_for "$dump_path")" -le "$threshold" ]; then
+        if [ -e "$ZCOMPDUMP_CACHE_PATH" ] && [ "$(_elapsed_seconds_for "$ZCOMPDUMP_CACHE_PATH")" -le "$threshold" ]; then
           # https://zsh.sourceforge.io/Doc/Release/Completion-System.html#Use-of-compinit
           # -C omit to check new functions
-          compinit -C -d "$dump_path"
+          compinit -C -d "$ZCOMPDUMP_CACHE_PATH"
         else
-          ${lib.getBin pkgs.coreutils}/bin/mkdir -p "$dump_dir"
-          compinit -d "$dump_path"
-          ${lib.getBin pkgs.coreutils}/bin/touch "$dump_path" # Ensure to update timestamp
+          # For refreshing the cache
+
+          ${lib.getBin pkgs.coreutils}/bin/mkdir -p "$ZCOMPDUMP_CACHE_DIR"
+          compinit -d "$ZCOMPDUMP_CACHE_PATH"
+          ${lib.getBin pkgs.coreutils}/bin/touch "$ZCOMPDUMP_CACHE_PATH" # Ensure to update timestamp
         fi
       }
     '';