Extend test with 0-ary case.

Author: cristianoc

tests/tests/src/pattern_match_json.mjs

@@ -29,7 +29,17 @@ function decodeGroup(group) {
   }
 }
 
+function decodeNull(x) {
+  let match = x.field;
+  if (match !== undefined && match === null) {
+    return "yes it's null";
+  } else {
+    return "no";
+  }
+}
+
 export {
   decodeGroup,
+  decodeNull,
 }
 /* No side effect */

tests/tests/src/pattern_match_json.res

@@ -18,3 +18,9 @@ let decodeGroup = group => {
   | _ => ("e", "f")
   }
 }
+
+let decodeNull = x =>
+  switch x {
+  | dict{"field": Null} => "yes it's null"
+  | _ => "no"
+  }