Make functional tests on NixOS use Meson not Make

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>

tests/functional/common/init.sh

@@ -19,7 +19,7 @@ EOF
 
   # When we're doing everything in the same store, we need to bring
   # dependencies into context.
-  sed -i "$(dirname "${BASH_SOURCE[0]}")"/../config.nix \
+  sed -i "${_NIX_TEST_BUILD_DIR}/config.nix" \
     -e 's^\(shell\) = "/nix/store/\([^/]*\)/\(.*\)";^\1 = builtins.appendContext "/nix/store/\2" { "/nix/store/\2".path = true; } + "/\3";^' \
     -e 's^\(path\) = "/nix/store/\([^/]*\)/\(.*\)";^\1 = builtins.appendContext "/nix/store/\2" { "/nix/store/\2".path = true; } + "/\3";^' \
     ;

tests/functional/common/subst-vars.sh.in

@@ -1,4 +1,4 @@
-# NOTE: instances of @variable@ are substituted as defined in /mk/templates.mk
+# NOTE: instances of @variable@ are substituted by the build system
 
 if [[ -z "${COMMON_SUBST_VARS_SH_SOURCED-}" ]]; then
 

tests/functional/meson.build

@@ -1,4 +1,4 @@
-project('nix-functional-tests', 'cpp',
+project('nix-functional-tests',
   version : files('.version'),
   default_options : [
     'cpp_std=c++2a',
@@ -170,6 +170,7 @@ suites = [
 
 nix_store = dependency('nix-store', required : false)
 if nix_store.found()
+  add_languages('cpp')
   subdir('test-libstoreconsumer')
   suites += {
     'name': 'libstoreconsumer',
@@ -187,6 +188,7 @@ endif
 # Plugin tests require shared libraries support.
 nix_expr = dependency('nix-expr', required : false)
 if nix_expr.found() and get_option('default_library') != 'static'
+  add_languages('cpp')
   subdir('plugins')
   suites += {
     'name': 'plugins',

tests/nixos/default.nix

@@ -21,7 +21,8 @@ let
       defaults = {
         nixpkgs.pkgs = nixpkgsFor.${system}.native;
         nix.checkAllErrors = false;
-        nix.package = noTests nixpkgsFor.${system}.native.nix;
+        # TODO: decide which packaging stage to use. `nix-cli` is efficient, but not the same as the user-facing `everything.nix` package (`default`). Perhaps a good compromise is `everything.nix` + `noTests` defined above?
+        nix.package = nixpkgsFor.${system}.native.nixComponents.nix-cli;
       };
       _module.args.nixpkgs = nixpkgs;
       _module.args.system = system;
@@ -33,10 +34,9 @@ let
       forNix = nixVersion: runNixOSTestFor system {
         imports = [test];
         defaults.nixpkgs.overlays = [(curr: prev: {
-          # NOTE: noTests pkg might not have been built yet for some older versions of the package
-          #       and in versions before 2.25, the untested build wasn't shared with the tested build yet
-          #       Add noTests here when those versions become irrelevant.
-          nix = (builtins.getFlake "nix/${nixVersion}").packages.${system}.nix;
+          nix = let
+            packages = (builtins.getFlake "nix/${nixVersion}").packages.${system};
+          in packages.nix-cli or packages.nix;
         })];
       };
     };

tests/nixos/functional/common.nix

@@ -24,47 +24,42 @@ in
     environment.systemPackages = let
       run-test-suite = pkgs.writeShellApplication {
         name = "run-test-suite";
-        runtimeInputs = [ pkgs.gnumake pkgs.jq pkgs.git ];
+        runtimeInputs = [
+          pkgs.meson
+          pkgs.ninja
+          pkgs.jq
+          pkgs.git
+
+          # Want to avoid `/run/current-system/sw/bin/bash` because we
+          # want a store path. Likewise for coreutils.
+          pkgs.bash
+          pkgs.coreutils
+        ];
         text = ''
           set -x
+
           cat /proc/sys/fs/file-max
           ulimit -Hn
           ulimit -Sn
+
           cd ~
-          cp -r ${pkgs.nix.overrideAttrs (o: {
-            name = "nix-configured-source";
-            outputs = [ "out" ];
-            separateDebugInfo = false;
-            disallowedReferences = [ ];
-            buildPhase = ":";
-            checkPhase = ":";
-            installPhase = ''
-              cp -r . $out
-            '';
-            installCheckPhase = ":";
-            fixupPhase = ":";
-            doInstallCheck = true;
-          })} nix
+
+          cp -r ${pkgs.nixComponents.nix-functional-tests.src} nix
           chmod -R +w nix
-          cd nix
 
-          # Tests we don't need
-          echo >tests/functional/plugins/local.mk
-          sed -i tests/functional/local.mk \
-            -e 's!nix_tests += plugins\.sh!!' \
-            -e 's!nix_tests += test-libstoreconsumer\.sh!!' \
-            ;
-
-          _NIX_TEST_SOURCE_DIR="$(realpath tests/functional)"
-          export _NIX_TEST_SOURCE_DIR
-          export _NIX_TEST_BUILD_DIR="''${_NIX_TEST_SOURCE_DIR}"
+          chmod u+w nix/.version
+          echo ${pkgs.nixComponents.version} > nix/.version
 
           export isTestOnNixOS=1
-          export version=${config.nix.package.version}
+
           export NIX_REMOTE_=daemon
           export NIX_REMOTE=daemon
+
           export NIX_STORE=${builtins.storeDir}
-          make -j1 installcheck --keep-going
+
+          meson setup nix/tests/functional build
+          cd build
+          meson test -j1 --print-errorlogs
         '';
       };
     in [