fix: adds bignumberish type to amount utilities, stop addNumberDecimals returning scientific notation (#2)

Author: digitalSloth

src/utilities/amounts.ts

@@ -1,15 +1,15 @@
-import { BigNumber } from "./bignumber.js";
+import { BigNumber, BigNumberish } from "./bignumber.js";
 import { Decimal } from "decimal.js";
 
 /**
  * Extract decimals from a number - converts human-readable amount to base units
- * @param num - The amount as a number (e.g., 1.5 ZNN)
+ * @param num - The amount as BigNumberish (e.g., 1.5, "1.5", bigint)
  * @param decimals - Number of decimals (e.g., 8 for ZNN)
  * @returns BigNumber representing the amount in base units
  * @example extractNumberDecimals(1.5, 8) => BigNumber(150000000)
  */
-export function extractNumberDecimals(num: number, decimals: number): BigNumber {
-    const decimal = new Decimal(num);
+export function extractNumberDecimals(num: BigNumberish, decimals: number): BigNumber {
+    const decimal = new Decimal(num.toString());
     const scalingFactor = new Decimal(10).pow(decimals);
     const result = decimal.times(scalingFactor);
     // Truncate to remove any fractional part (matching Dart SDK behavior)
@@ -23,10 +23,10 @@ export function extractNumberDecimals(num: number, decimals: number): BigNumber
  * @returns String representing the human-readable amount
  * @example addNumberDecimals(150000000, 8) => "1.5"
  */
-export function addNumberDecimals(num: number, decimals: number): string {
-    const decimal = new Decimal(num);
+export function addNumberDecimals(num: BigNumberish, decimals: number): string {
+    const decimal = new Decimal(num.toString());
     const scalingFactor = new Decimal(10).pow(decimals);
     const result = decimal.dividedBy(scalingFactor);
-    return result.toString();
+    return result.toFixed();
 }
 

test/utilities/amount.spec.ts

@@ -6,6 +6,7 @@ describe("Amount", () => {
         it("should multiply number by 10^decimals and return BigNumber", () => {
             expect(extractNumberDecimals(5, 2).toString()).to.equal("500");
             expect(extractNumberDecimals(1.23, 3).toString()).to.equal("1230");
+            expect(extractNumberDecimals(0.00000001, 8).toString()).to.equal("1");
             expect(extractNumberDecimals(0, 5).toString()).to.equal("0");
         });
 
@@ -34,6 +35,7 @@ describe("Amount", () => {
         it("should divide number by 10^decimals and return string", () => {
             expect(addNumberDecimals(500, 2)).to.equal("5");
             expect(addNumberDecimals(1230, 3)).to.equal("1.23");
+            expect(addNumberDecimals(1, 8)).to.equal("0.00000001");
             expect(addNumberDecimals(0, 5)).to.equal("0");
         });