From 8bbefa77f7e95c80005350aeac6fe425ce47c288 Mon Sep 17 00:00:00 2001
From: Robert Helgesson <robert@rycee.net>
Date: Thu, 28 May 2020 01:24:49 +0200
Subject: [PATCH] tests: perform code formatting test in test suite

This should improve visibility when CI job fails due to bad
formatting.
---
 .gitlab-ci.yml            |  1 -
 .travis.yml               |  1 -
 tests/default.nix         |  1 +
 tests/meta/default.nix    |  1 +
 tests/meta/formatting.nix | 27 +++++++++++++++++++++++++++
 5 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 tests/meta/default.nix
 create mode 100644 tests/meta/formatting.nix

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6a227fa5..2c5c5a67 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -11,7 +11,6 @@ stages:
 Run tests:
   stage: test
   script:
-    - ./format -c && echo Format is OK
     - nix-shell --pure tests -A run.files-text
   rules:
     - if: $CI_COMMIT_BRANCH == "master"
diff --git a/.travis.yml b/.travis.yml
index 039551c4..c2599e92 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,5 @@ os:
   - osx
 
 script:
-  - ./format -c
   - nix-shell . -A install
   - nix-shell --pure --max-jobs 10 tests -A run.all
diff --git a/tests/default.nix b/tests/default.nix
index d7f5222c..3143eb9e 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -59,6 +59,7 @@ import nmt {
     ./modules/programs/zsh
     ./modules/xresources
   ] ++ lib.optionals pkgs.stdenv.hostPlatform.isLinux [
+    ./meta # Suffices to run on one platform.
     ./modules/misc/debug
     ./modules/misc/pam
     ./modules/misc/xdg
diff --git a/tests/meta/default.nix b/tests/meta/default.nix
new file mode 100644
index 00000000..0f02fcfb
--- /dev/null
+++ b/tests/meta/default.nix
@@ -0,0 +1 @@
+{ meta-formatting = ./formatting.nix; }
diff --git a/tests/meta/formatting.nix b/tests/meta/formatting.nix
new file mode 100644
index 00000000..2d5800c5
--- /dev/null
+++ b/tests/meta/formatting.nix
@@ -0,0 +1,27 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  pinnedNixpkgs = builtins.fetchTarball {
+    url =
+      "https://github.com/NixOS/nixpkgs/archive/05f0934825c2a0750d4888c4735f9420c906b388.tar.gz";
+    sha256 = "1g8c2w0661qn89ajp44znmwfmghbbiygvdzq0rzlvlpdiz28v6gy";
+  };
+
+  pinnedPkgs = import pinnedNixpkgs { };
+
+in {
+  config = {
+    nmt.script = ''
+      PATH="${with pinnedPkgs; lib.makeBinPath [ findutils nixfmt ]}:$PATH"
+      cd ${../..}
+      if ! ${pkgs.runtimeShell} format -c; then
+        fail "${''
+        Expected source code to be formatted with nixfmt but it was not.
+        This error can be resolved by running the './format' in the project root directory.''}"
+      fi
+    '';
+  };
+}