xdg-mime type package options (#5920)

* xdg-mime: allow overrides to shared-mime-info and desktop-file-utils

The `xdg-mime` module now exposes packages to determine what will be run
for update-mime-database and update-desktop-database. This allows users
to select a different version of these packages if the are incompatible.
This should, in combination with an override to the version of
`shared-mime-info` (can be found here notalltim/home-manager-config#4),
resolve #4955, #5102, #4682, and possibly #4941. The problem seems to stem
from a mismatch in the version of `shared-mime-info` with the host.

I also switched from using `buildPackages` to `pkgs` to improve
cross-compilation compatibility.

* xdg-mime: Add tests for xdg-mime module

The xdg-mime module was missing tests so I added basic test for all the
options and checked the basic behavior. It covers ensuring that the
proper files/folders are created and that the package overrides work.

modules/misc/xdg-mime.nix

@@ -5,10 +5,12 @@ with lib;
 let
 
   cfg = config.xdg.mime;
+  inherit (lib) getExe getExe';
 
 in {
   options = {
-    xdg.mime.enable = mkOption {
+    xdg.mime = {
+      enable = mkOption {
         type = types.bool;
         default = pkgs.stdenv.hostPlatform.isLinux;
         defaultText =
@@ -23,15 +25,30 @@ in {
           respectively.
         '';
       };
+
+      sharedMimeInfoPackage = mkOption {
+        type = types.package;
+        default = pkgs.shared-mime-info;
+        defaultText = literalExpression "pkgs.shared-mime-info";
+        description = "The package to use when running update-mime-database.";
       };
 
-  config = mkIf config.xdg.mime.enable {
+      desktopFileUtilsPackage = mkOption {
+        type = types.package;
+        default = pkgs.desktop-file-utils;
+        defaultText = literalExpression "pkgs.desktop-file-utils";
+        description =
+          "The package to use when running update-desktop-database.";
+      };
+    };
+  };
+  config = mkIf cfg.enable {
     assertions =
       [ (hm.assertions.assertPlatform "xdg.mime" pkgs platforms.linux) ];
 
     home.packages = [
       # Explicitly install package to provide basic mime types.
-      pkgs.shared-mime-info
+      cfg.sharedMimeInfoPackage
 
       # Make sure the target directories will be real directories.
       (pkgs.runCommandLocal "dummy-xdg-mime-dirs1" { } ''
@@ -46,12 +63,12 @@ in {
       if [[ -w $out/share/mime && -w $out/share/mime/packages && -d $out/share/mime/packages ]]; then
         XDG_DATA_DIRS=$out/share \
         PKGSYSTEM_ENABLE_FSYNC=0 \
-        ${pkgs.buildPackages.shared-mime-info}/bin/update-mime-database \
+        ${getExe cfg.sharedMimeInfoPackage} \
           -V $out/share/mime > /dev/null
       fi
 
       if [[ -w $out/share/applications ]]; then
-        ${pkgs.buildPackages.desktop-file-utils}/bin/update-desktop-database \
+        ${getExe' cfg.desktopFileUtilsPackage "update-desktop-database"} \
           $out/share/applications
       fi
     '';

tests/modules/misc/xdg/default.nix

@@ -6,4 +6,7 @@
   xdg-default-locations = ./default-locations.nix;
   xdg-user-dirs-null = ./user-dirs-null.nix;
   xdg-portal = ./portal.nix;
+  xdg-mime = ./mime.nix;
+  xdg-mime-disabled = ./mime-disabled.nix;
+  xdg-mime-package = ./mime-packages.nix;
 }

tests/modules/misc/xdg/mime-disabled.nix

@@ -0,0 +1,10 @@
+{ ... }: {
+  config = {
+    xdg.mime.enable = false;
+    nmt.script = ''
+      # assert that neither application is run
+      assertPathNotExists home-path/share/applications/mimeinfo.cache
+      assertPathNotExists home-path/share/applications/mime
+    '';
+  };
+}

tests/modules/misc/xdg/mime-expected.cache

@@ -0,0 +1,3 @@
+[MIME Cache]
+text/html=mime-test.desktop;
+text/xml=mime-test.desktop;

tests/modules/misc/xdg/mime-packages.nix

@@ -0,0 +1,38 @@
+{ config, ... }:
+let inherit (config.lib.test) mkStubPackage;
+in {
+  config = {
+    xdg.mime.enable = true;
+    xdg.mime.sharedMimeInfoPackage = mkStubPackage {
+      name = "update-mime-database";
+      buildScript = ''
+        mkdir -p $out/bin
+        echo '#!/bin/sh' > $out/bin/update-mime-database
+        echo 'mkdir -p $out/share/mime && touch $out/share/mime/mime.cache' >> $out/bin/update-mime-database
+        chmod +x $out/bin/update-mime-database
+      '';
+    };
+    xdg.mime.desktopFileUtilsPackage = mkStubPackage {
+      name = "desktop-file-utils";
+      buildScript = ''
+        mkdir -p $out/bin
+        echo '#!/bin/sh' > $out/bin/update-desktop-database
+        echo 'mkdir -p $out/share/applications/ && ln -s ${
+          ./mime-expected.cache
+        } $out/share/applications/mimeinfo.cache' >> $out/bin/update-desktop-database
+        chmod +x $out/bin/update-desktop-database
+      '';
+    };
+    nmt.script = ''
+      assertFileExists home-path/share/applications/mimeinfo.cache # Check that update-desktop-database created file
+      # Check that update-desktop-database file matches expected
+      assertFileContent \
+      home-path/share/applications/mimeinfo.cache \
+        ${./mime-expected.cache}
+
+      assertDirectoryExists home-path/share/mime # Check that update-mime-database created directory
+      assertFileExists home-path/share/mime/mime.cache # Check that update-mime-database created file
+
+    '';
+  };
+}

tests/modules/misc/xdg/mime.nix

@@ -0,0 +1,24 @@
+{ ... }: {
+  config = {
+    xdg.mime.enable = true;
+    xdg.desktopEntries = {
+      mime-test = { # mime info test
+        name = "mime-test";
+        mimeType = [ "text/html" "text/xml" ];
+      };
+
+    };
+
+    nmt.script = ''
+      assertFileExists home-path/share/applications/mimeinfo.cache # Check that update-desktop-database created file
+      # Check that update-desktop-database file matches expected
+      assertFileContent \
+        home-path/share/applications/mimeinfo.cache \
+        ${./mime-expected.cache}
+
+      assertDirectoryExists home-path/share/mime # Check that update-mime-database created directory
+      assertDirectoryNotEmpty home-path/share/mime # Check that update-mime-database created files
+
+    '';
+  };
+}