lib/modules: Fix type checks not being done before merging

Co-Authored-By: Robert Hensing <robert@roberthensing.nl>

lib/modules.nix

@@ -416,10 +416,9 @@ rec {
     # Type-check the remaining definitions, and merge them. Or throw if no definitions.
     mergedValue =
       if isDefined then
-        foldl' (res: def:
-          if type.check def.value then res
-          else throw "The option value `${showOption loc}' in `${def.file}' is not of type `${type.description}'."
-        ) (type.merge loc defsFinal) defsFinal
+        if all (def: type.check def.value) defsFinal then type.merge loc defsFinal
+        else let firstInvalid = findFirst (def: ! type.check def.value) null defsFinal;
+        in throw "The option value `${showOption loc}' in `${firstInvalid.file}' is not of type `${type.description}'."
       else
         # (nixos-option detects this specific error message and gives it special
         # handling.  If changed here, please change it there too.)

lib/tests/modules.sh

@@ -198,6 +198,10 @@ checkConfigOutput "empty" config.value.foo ./declare-lazyAttrsOf.nix ./attrsOf-c
 checkConfigError 'The option path .* is an attribute set of options, but it is defined to not be an attribute set in' \
   config.value ./declare-option-set.nix ./define-value-int-zero.nix
 
+# Even with multiple assignments, a type error should be thrown if any of them aren't valid
+checkConfigError 'The option value .* in .* is not of type .*' \
+  config.value ./declare-int-unsigned-value.nix ./define-value-list.nix ./define-value-int-positive.nix
+
 cat <<EOF
 ====== module tests ======
 $pass Pass