tests: move test derivations to tests/default.nix

Move the previous `default.nix` to `main.nix` so that `default.nix` can
be used for defining the set of all test derivations.

`main.nix` is imported by `default.nix`, but is only responsible for the
tests built from `tests/test-sources/`.

flake-modules/tests.nix

@@ -1,57 +1,27 @@
-{ self, helpers, ... }:
+{
+  self,
+  lib,
+  helpers,
+  ...
+}:
 {
   perSystem =
     {
       pkgs,
       pkgsUnfree,
       system,
-      makeNixvimWithModule,
-      self',
       ...
     }:
-    let
-      inherit (self'.legacyPackages) nixvimConfiguration;
-    in
     {
-      checks = {
+      checks = import ../tests {
-        extra-args-tests = import ../tests/extra-args.nix {
+        inherit
-          inherit pkgs;
+          helpers
-          inherit makeNixvimWithModule;
+          lib
+          pkgs
+          pkgsUnfree
+          self
+          system
+          ;
       };
-
-        extend = import ../tests/extend.nix { inherit pkgs makeNixvimWithModule; };
-
-        extra-files = import ../tests/extra-files.nix { inherit pkgs makeNixvimWithModule; };
-
-        enable-except-in-tests = import ../tests/enable-except-in-tests.nix {
-          inherit pkgs makeNixvimWithModule;
-          inherit (self.lib.${system}.check) mkTestDerivationFromNixvimModule;
-        };
-
-        failing-tests = pkgs.callPackage ../tests/failing-tests.nix {
-          inherit (self.lib.${system}.check) mkTestDerivationFromNixvimModule;
-        };
-
-        no-flake = import ../tests/no-flake.nix {
-          inherit system;
-          inherit (self.lib.${system}.check) mkTestDerivationFromNvim;
-          nixvim = "${self}";
-        };
-
-        lib-tests = import ../tests/lib-tests.nix {
-          inherit pkgs helpers;
-          inherit (pkgs) lib;
-        };
-
-        maintainers = import ../tests/maintainers.nix { inherit pkgs; };
-
-        plugins-by-name = pkgs.callPackage ../tests/plugins-by-name.nix { inherit nixvimConfiguration; };
-
-        generated = pkgs.callPackage ../tests/generated.nix { };
-
-        package-options = pkgs.callPackage ../tests/package-options.nix { inherit nixvimConfiguration; };
-
-        lsp-all-servers = pkgs.callPackage ../tests/lsp-servers.nix { inherit nixvimConfiguration; };
-      } // import ../tests { inherit pkgs pkgsUnfree helpers; };
     };
 }

tests/default.nix

@@ -1,65 +1,53 @@
 {
-  lib ? pkgs.lib,
-  helpers,
   pkgs,
   pkgsUnfree,
+  helpers,
+  lib,
+  system,
+  self, # The flake instance
 }:
 let
-  fetchTests = import ./fetch-tests.nix { inherit lib pkgs helpers; };
+  inherit (self.legacyPackages.${system})
-  test-derivation = import ../lib/tests.nix { inherit pkgs lib; };
+    makeNixvimWithModule
-  inherit (test-derivation) mkTestDerivationFromNixvimModule;
+    nixvimConfiguration
-
+    ;
-  moduleToTest =
-    file: name: module:
-    mkTestDerivationFromNixvimModule {
-      inherit name;
-      module = {
-        _file = file;
-        imports = [ module ];
-      };
-      pkgs = pkgsUnfree;
-    };
-
-  # List of files containing configurations
-  testFiles = fetchTests ./test-sources;
-
-  exampleFiles = {
-    name = "examples";
-    file = ../example.nix;
-    cases =
-      let
-        config = import ../example.nix { inherit pkgs; };
-      in
-      {
-        main = builtins.removeAttrs config.programs.nixvim [
-          # This is not available to standalone modules, only HM & NixOS Modules
-          "enable"
-          # This is purely an example, it does not reflect a real usage
-          "extraConfigLua"
-          "extraConfigVim"
-        ];
-      };
-  };
 in
-# We attempt to build & execute all configurations
+{
-lib.pipe (testFiles ++ [ exampleFiles ]) [
+  extra-args-tests = import ./extra-args.nix {
-  (builtins.map (
+    inherit pkgs;
-    {
+    inherit makeNixvimWithModule;
-      name,
+  };
-      file,
+  extend = import ./extend.nix { inherit pkgs makeNixvimWithModule; };
-      cases,
+  extra-files = import ./extra-files.nix { inherit pkgs makeNixvimWithModule; };
-    }:
+  enable-except-in-tests = import ./enable-except-in-tests.nix {
-    {
+    inherit pkgs makeNixvimWithModule;
-      inherit name;
+    inherit (self.lib.${system}.check) mkTestDerivationFromNixvimModule;
-      path = pkgs.linkFarm name (builtins.mapAttrs (moduleToTest file) cases);
+  };
-    }
+  failing-tests = pkgs.callPackage ./failing-tests.nix {
-  ))
+    inherit (self.lib.${system}.check) mkTestDerivationFromNixvimModule;
-  (helpers.groupListBySize 10)
+  };
-  (lib.imap1 (
+  no-flake = import ./no-flake.nix {
-    i: group: rec {
+    inherit system;
-      name = "test-${toString i}";
+    inherit (self.lib.${system}.check) mkTestDerivationFromNvim;
-      value = pkgs.linkFarm name group;
+    nixvim = "${self}";
-    }
+  };
-  ))
+  lib-tests = import ./lib-tests.nix {
-  builtins.listToAttrs
+    inherit pkgs helpers;
-]
+    inherit (pkgs) lib;
+  };
+  maintainers = import ./maintainers.nix { inherit pkgs; };
+  plugins-by-name = pkgs.callPackage ./plugins-by-name.nix { inherit nixvimConfiguration; };
+  generated = pkgs.callPackage ./generated.nix { };
+  package-options = pkgs.callPackage ./package-options.nix { inherit nixvimConfiguration; };
+  lsp-all-servers = pkgs.callPackage ./lsp-servers.nix { inherit nixvimConfiguration; };
+}
+# Tests generated from ./test-sources
+# Grouped as a number of link-farms in the form { test-1, test-2, ... test-N }
+// import ./main.nix {
+  inherit
+    lib
+    pkgs
+    pkgsUnfree
+    helpers
+    ;
+}

tests/main.nix

@@ -0,0 +1,66 @@
+# Collects the various test modules in tests/test-sources/ and groups them into a number of test derivations
+{
+  lib ? pkgs.lib,
+  helpers,
+  pkgs,
+  pkgsUnfree,
+}:
+let
+  fetchTests = import ./fetch-tests.nix { inherit lib pkgs helpers; };
+  test-derivation = import ../lib/tests.nix { inherit pkgs lib; };
+  inherit (test-derivation) mkTestDerivationFromNixvimModule;
+
+  moduleToTest =
+    file: name: module:
+    mkTestDerivationFromNixvimModule {
+      inherit name;
+      module = {
+        _file = file;
+        imports = [ module ];
+      };
+      pkgs = pkgsUnfree;
+    };
+
+  # List of files containing configurations
+  testFiles = fetchTests ./test-sources;
+
+  exampleFiles = {
+    name = "examples";
+    file = ../example.nix;
+    cases =
+      let
+        config = import ../example.nix { inherit pkgs; };
+      in
+      {
+        main = builtins.removeAttrs config.programs.nixvim [
+          # This is not available to standalone modules, only HM & NixOS Modules
+          "enable"
+          # This is purely an example, it does not reflect a real usage
+          "extraConfigLua"
+          "extraConfigVim"
+        ];
+      };
+  };
+in
+# We attempt to build & execute all configurations
+lib.pipe (testFiles ++ [ exampleFiles ]) [
+  (builtins.map (
+    {
+      name,
+      file,
+      cases,
+    }:
+    {
+      inherit name;
+      path = pkgs.linkFarm name (builtins.mapAttrs (moduleToTest file) cases);
+    }
+  ))
+  (helpers.groupListBySize 10)
+  (lib.imap1 (
+    i: group: rec {
+      name = "test-${toString i}";
+      value = pkgs.linkFarm name group;
+    }
+  ))
+  builtins.listToAttrs
+]