Fix the module define logic, handles missing base and numbers in the loaded module

I think Lua internals return a number sometimes which breaks all sorts,
so we want to ignore nil and numbers, everything else is fair game (like
tables, functions and strings)

Author: Olical

fnl/nfnl/module.fnl

@@ -58,8 +58,8 @@
   The base value defaults to {}, an empty table."
 
   (let [loaded (. package.loaded mod-name)]
-    (if (and (= (type loaded) (type base))
-             (not= nil loaded))
+    (if (and (or (= (type loaded) (type base)) (= nil base))
+             (and (not= nil loaded) (not= :number (type loaded))))
       loaded
       (or base {}))))
 

fnl/spec/nfnl/module_spec.fnl

@@ -17,6 +17,9 @@
   (fn []
     (it "returns the loaded module if it's the same type as the base"
         (fn []
+          (local m1 (define :nfnl.module))
+          (assert.equals define m1.define)
+
           (local m2 (define :nfnl.module {}))
           (assert.equals define m2.define)