zsh: consider zsh.{profile,login,logout,env}Extra in prezto

Right now the `zsh.prezto` module ignores the contents of the
`zsh.{profile,login,logout,env}Extra` options, so it means that if you
try to set, e.g., `zsh.profileExtra = "something";` this option will be
(silently) ignored.

This commit fixes another issue: since the main `zsh` module sets
`home.file."${relToDotDir".zshenv"}".text` while `zsh.prezto` set the
same file using `.source`, `zsh.prezto` would have priority so the
environment variables from Home-Manager would not be loaded in non-NixOS
systems. Now that we are using `.text` for both, the issue is fixed.

modules/programs/zsh/prezto.nix

@@ -13,6 +13,7 @@ let
     ;
 
   cfg = config.programs.zsh.prezto;
+  cfgZsh = config.programs.zsh;
 
   relToDotDir =
     file:
@@ -423,12 +424,30 @@ in
   config = lib.mkIf cfg.enable (
     lib.mkMerge [
       {
-        home.file."${relToDotDir ".zprofile"}".source = "${cfg.package}/share/zsh-prezto/runcoms/zprofile";
-        home.file."${relToDotDir ".zlogin"}".source = "${cfg.package}/share/zsh-prezto/runcoms/zlogin";
-        home.file."${relToDotDir ".zlogout"}".source = "${cfg.package}/share/zsh-prezto/runcoms/zlogout";
         home.packages = [ cfg.package ];
 
-        home.file."${relToDotDir ".zshenv"}".source = "${cfg.package}/share/zsh-prezto/runcoms/zshenv";
+        home.file."${relToDotDir ".zprofile"}".text = ''
+          # Generated by Nix
+          source ${cfg.package}/share/zsh-prezto/runcoms/zprofile
+          ${cfgZsh.profileExtra}
+        '';
+        home.file."${relToDotDir ".zlogin"}".text = ''
+          # Generated by Nix
+          source ${cfg.package}/share/zsh-prezto/runcoms/zlogin
+          ${cfgZsh.loginExtra}
+        '';
+        home.file."${relToDotDir ".zlogout"}".text = ''
+          # Generated by Nix
+          source ${cfg.package}/share/zsh-prezto/runcoms/zlogout
+          ${cfgZsh.logoutExtra}
+        '';
+        # Using mkAfter to make sure we load Home-Manager's environment
+        # variables first (see modules/prgrams/zsh.nix)
+        home.file."${relToDotDir ".zshenv"}".text = lib.mkAfter ''
+          # Generated by Nix
+          source ${cfg.package}/share/zsh-prezto/runcoms/zshenv
+          ${cfgZsh.envExtra}
+        '';
         home.file."${relToDotDir ".zpreztorc"}".text = ''
           # Generated by Nix
           ${optionalString (cfg.caseSensitive != null) ''

tests/modules/programs/zsh/prezto.nix

@@ -1,5 +1,16 @@
 {
-  programs.zsh.prezto.enable = true;
+  programs.zsh = {
+    enable = true;
+    envExtra = "envExtra";
+    profileExtra = "profileExtra";
+    loginExtra = "loginExtra";
+    logoutExtra = "logoutExtra";
+    sessionVariables.FOO = "bar";
+    prezto = {
+      enable = true;
+      extraConfig = "configExtra";
+    };
+  };
 
   test.stubs = {
     zsh-prezto = {
@@ -10,11 +21,21 @@
         echo '# zlogin' > $out/share/zsh-prezto/runcoms/zlogin
         echo '# zlogout' > $out/share/zsh-prezto/runcoms/zlogout
         echo '# zshenv' > $out/share/zsh-prezto/runcoms/zshenv
+        echo '# zshrc' > $out/share/zsh-prezto/runcoms/zshrc
       '';
     };
   };
 
   nmt.script = ''
-    assertFileExists home-files/.zpreztorc
+    assertFileContains home-files/.zpreztorc 'configExtra'
+    assertFileContains home-files/.zprofile 'profileExtra'
+    assertFileContains home-files/.zlogin 'loginExtra'
+    assertFileContains home-files/.zlogout 'logoutExtra'
+    assertFileContains home-files/.zshenv 'envExtra'
+    # make sure we are loading the environment variables
+    assertFileContains home-files/.zshenv \
+      '. "/home/hm-user/.nix-profile/etc/profile.d/hm-session-vars.sh"'
+    assertFileContains home-files/.zshenv \
+      'export FOO="bar"'
   '';
 }