fix: approval of amounts with big decimals (#21326)

Signed-off-by: Brian Sztamfater <brian@status.im>

src/status_im/contexts/wallet/common/utils.cljs

@@ -391,7 +391,7 @@
         approval-amount-required           (:approval-amount-required route)
         approval-amount-required-sanitized (-> approval-amount-required
                                                (utils.hex/normalize-hex)
-                                               (native-module/hex-to-number))
+                                               (money/from-hex))
         approval-contract-address          (:approval-contract-address route)
         data                               (native-module/encode-function-call
                                             constants/contract-function-signature-erc20-approve

src/utils/money.cljs

@@ -151,6 +151,12 @@
   [^js bn]
   (str "0x" (to-string bn 16)))
 
+(defn from-hex
+  [hex-str]
+  (try
+    (new BigNumber hex-str 16)
+    (catch :default _ nil)))
+
 (defn wei->str
   ([unit n display-unit]
    (str (to-fixed (wei-> unit n)) " " display-unit))

src/utils/money_test.cljs

@@ -83,3 +83,10 @@
    1000001   "1M"
    10000000  "10M"
    100000000 "100M"))
+
+(deftest from-hex-test
+  (is (= (money/bignumber "2840425681744351250") (money/from-hex "276b381bbb44d012")))
+  (is (= (money/bignumber "0") (money/from-hex "0")))
+  (is (= (money/bignumber "255") (money/from-hex "ff")))
+  (is (= (money/bignumber "4294967295") (money/from-hex "ffffffff")))
+  (is (= (money/bignumber "12345678901234567890") (money/from-hex "ab54a98ceb1f0ad2"))))