Add testScript option

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ## Unreleased
 
-- ...
+- Add `testScript` option for adding flake checks based on nixosTest library.
 
 ## 0.1.0 (Jun 12, 2023)
 

nix/flake-module.nix

@@ -29,9 +29,14 @@ in
         });
       };
 
-      config.packages = lib.mapAttrs
-        (name: cfg: cfg.outputs.package)
-        config.process-compose;
+      config = {
+        packages = lib.mapAttrs
+          (name: cfg: cfg.outputs.package)
+          config.process-compose;
+        checks = lib.mapAttrs
+          (name: cfg: cfg.outputs.check)
+          config.process-compose;
+      };
     });
 }
 

nix/process-compose/default.nix

@@ -7,6 +7,7 @@ in
   imports = [
     ./cli.nix
     ./settings
+    ./test.nix
   ];
 
   options = {

nix/process-compose/test.nix

@@ -0,0 +1,47 @@
+{ name, config, pkgs, lib, ... }:
+
+let
+  inherit (lib) types mkOption;
+in
+{
+  options = {
+    testScript = mkOption {
+      type = types.nullOr types.str;
+      description = ''
+        If set, add a flake check running nixosTest running this process-compose
+        configuration, followed by the specified testScript.
+
+        Useful if you want to test your configuration in CI.
+      '';
+      default = null;
+    };
+    outputs.check = mkOption {
+      type = types.nullOr types.package;
+      default = if config.testScript == null then null else 
+        pkgs.nixosTest {
+          inherit (config) testScript;
+          name = "process-compose-${name}-test";
+          nodes.machine = {
+            environment.systemPackages = [ pkgs.bash ]; # process-compose requires it.
+            systemd.services.process-compose = {
+              enable = true;
+              wantedBy = [ "default.target" ];
+              serviceConfig = {
+                WorkingDirectory = "/tmp";
+                ExecStart = lib.getExe (pkgs.writeShellApplication {
+                  name = "process-compose-${name}";
+                  text = ''
+                    set -x
+                    echo "Launching procese-compose on ${name} ..."
+                    # make bash available to process-compose
+                    export PATH=/run/current-system/sw/bin:$PATH
+                    ${lib.getExe config.outputs.package} -t=false
+                  '';
+                });
+              };
+            };
+          };
+        };
+    }; 
+  };
+}