feat: finally get a stupid simple test suite up and running

.github/workflows/check.yaml

@@ -0,0 +1,18 @@
+name: Build example and run tests
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v25
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+      - run: nix build ./example
+      - run: nix run ./example#test

example/flake.nix

@@ -27,9 +27,13 @@
 
           lazy = {
             settings = {
-              disabled_plugins = [
-                "gzip"
-              ];
+              performance.rtp = {
+                disabled_plugins = [
+                  "gzip"
+                  "matchit"
+                  "netrwPlugin"
+                ];
+              };
             };
             plugins = {
               example = {
@@ -39,14 +43,13 @@
                 priority = 1000;
                 dependencies = {
                   lfs = let
-                    package = pkgs.luajitPackages.lfs;
+                    package = pkgs.luajitPackages.luafilesystem;
                   in {
                     inherit package;
                     init = pkgs.writeTextFile {
                       name = "lfs.lua";
                       text = ''
                         return function()
-                          -- TODO: It'd be nice to detect this automatically
                           package.cpath = package.cpath .. ";" .. "${package}/lib/lua/5.1/?.so"
                         end
                       '';
@@ -63,7 +66,16 @@
           };
         };
 
-        packages.default = config.neovim.final;
+        packages = {
+          default = config.neovim.final;
+          test = pkgs.writeShellApplication {
+            name = "neovim-nix-spec";
+            runtimeInputs = [config.neovim.final];
+            text = ''
+              nvim --headless -c "PlenaryBustedDirectory ${./.}/spec { init = '${config.neovim.build.initlua}' }"
+            '';
+          };
+        };
       };
     };
 }

spec/init.lua → example/spec/features_spec.lua

@@ -1,36 +1,37 @@
 describe("neovim", function()
   it("(env) sets environment variables", function()
-    assert.equal("true", vim.env.BUILT_WITH_NEOVIM_NIX)
+    assert.equal("1", vim.env.BUILT_WITH_NEOVIM_NIX)
   end)
 
   it("(paths) adds to PATH", function()
-    assert.is_executable "stylua"
+    assert.equal(1, vim.fn.executable "stylua")
   end)
 
   describe("lazy", function()
     it("(settings) disables builtin plugins", function()
-      assert.is_true(vim.fn.exists "loaded_gzip" == 0)
+      assert.equal(0, vim.fn.exists "loaded_gzip")
+      assert.equal(0, vim.fn.exists "loaded_matchit")
+      assert.equal(0, vim.fn.exists "loaded_netrwPlugin")
     end)
 
     describe("plugins", function()
       local _, example = pcall(require, "example")
 
       it("(<name>) adds plugins", function()
-        assert.is_table(package.loaded.example)
         assert.is_function(example.say_hello)
       end)
 
       it("(dependencies) adds plugin dependencies", function()
-        assert.is_table(package.loaded.lfs)
-        assert.is_table(package.loaded.plenary)
+        assert.is_table(require "lfs")
+        assert.is_table(require "plenary")
       end)
 
       it("(config) configures plugins", function()
         assert.is_true(vim.g.loaded_example)
       end)
 
       it("(paths) add plugin specific paths to PATH", function()
-        assert.is_executable "luacheck"
+        assert.equal(1, vim.fn.executable "luacheck")
       end)
     end)
   end)

flake.nix

@@ -7,18 +7,6 @@
     lazy-nvim.url = "github:folke/lazy.nvim";
     lazy-nvim.flake = false;
     pre-commit-nix.url = "github:cachix/pre-commit-hooks.nix";
-
-    # FIXME: This would be nice, and also a test of sorts
-    # example = {
-    #   url = "path:./example";
-    #   inputs = {
-    #     # FIXME: override for a non-existent input 'nixpkgs'
-    #     # nixpkgs.follows = "nixpkgs";
-    #     flake-parts.follows = "flake-parts";
-    #     # FIXME: override for a non-existent input 'neovim-nix'
-    #     # neovim-nix.follows = "self";
-    #   };
-    # };
   };
 
   outputs = {
@@ -55,7 +43,6 @@
         formatter = pkgs.alejandra;
 
         packages = {
-          # example = inputs'.example.packages.default;
           utils = pkgs.callPackage ./utils.nix {};
         };