Fix decimal coercion when already a BigDecimal

...like when loading a ledger w/ file conn. Fixes #436.

src/fluree/db/datatype.cljc

@@ -6,8 +6,7 @@
                :cljs [fluree.db.util.cljs-const :as uc]))
   #?(:clj (:import (java.time OffsetDateTime OffsetTime LocalDate LocalTime
                               LocalDateTime ZoneOffset)
-                   (java.time.format DateTimeFormatter)
-                   (java.math BigDecimal))))
+                   (java.time.format DateTimeFormatter))))
 
 #?(:clj (set! *warn-on-reflection* true))
 
@@ -190,16 +189,20 @@
   [value]
   (cond
     (string? value)
-    #?(:clj  (try (BigDecimal. ^String value) (catch Exception _ nil))
+    #?(:clj  (try (bigdec value) (catch Exception _ nil))
        :cljs (let [n (js/parseFloat value)] (if (js/Number.isNaN n) nil n)))
 
     (integer? value)
-    #?(:clj  (BigDecimal. ^int value)
+    #?(:clj  (bigdec value)
        :cljs value)
 
     (float? value)
     ;; convert to string first to keep float precision explosion at bay
-    #?(:clj  (BigDecimal. ^String (Float/toString value))
+    #?(:clj  (bigdec (Float/toString value))
+       :cljs value)
+
+    (number? value)
+    #?(:clj  (bigdec value)
        :cljs value)
 
     :else nil))

test/fluree/db/datatype_test.cljc

@@ -90,11 +90,11 @@
     (is (= nil (coerce "foo" const/$xsd:dateTime))))
 
   (testing "decimal"
-    (is (= #?(:clj (BigDecimal. "3.14") :cljs 3.14)
+    (is (= #?(:clj (bigdec "3.14") :cljs 3.14)
            (coerce 3.14 const/$xsd:decimal)))
-    (is (= #?(:clj (BigDecimal. "3.14") :cljs 3.14)
+    (is (= #?(:clj (bigdec "3.14") :cljs 3.14)
            (coerce "3.14" const/$xsd:decimal)))
-    (is (= #?(:clj (BigDecimal. "42.0") :cljs 42)
+    (is (= #?(:clj (bigdec "42.0") :cljs 42)
            (coerce 42 const/$xsd:decimal)))
     (is (= #?(:clj (bigdec 99.99) :cljs 99.99)
            (coerce #?(:clj (bigdec 99.99) :cljs 99.99) const/$xsd:decimal)))