From ca0cf11ca9fe1fd80c8edeb71d2a66016d9798d5 Mon Sep 17 00:00:00 2001
From: Vincent Ambo <tazjin@google.com>
Date: Thu, 8 Aug 2019 15:07:36 +0100
Subject: feat: Improved error message for missing struct fields

---
 yants.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'yants.nix')

diff --git a/yants.nix b/yants.nix
index 3dfebfcf1fa0..a00d084392d3 100644
--- a/yants.nix
+++ b/yants.nix
@@ -35,7 +35,8 @@ with builtins; let
       type = def."${field}";
       checked = type.check fieldVal;
   in if checked then (current && true)
-     else (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}");
+     else if isNull fieldVal then (throw "Missing required ${type.name} field '${field}'")
+          else  (throw "Field ${field} is of type ${typeOf fieldVal}, but expected ${type.name}");
 
   checkExtraneous = name: def: present:
   if (length present) == 0 then true
-- 
cgit 1.4.1