#350: Support extremely large numbers

lib/src/cosmos/coins.spec.ts

@@ -12,12 +12,23 @@ describe('coins', function () {
             });
         });
 
+        it('works for high value amount', function () {
+            expect(coin('100000000234500000000000000', 'utoken')).to.deep.eq({
+                amount: '100000000234500000000000000',
+                denom: 'utoken',
+            });
+            expect(coin('100000000234500000000000000123123123123', 'utoken')).to.deep.eq({
+                amount: '100000000234500000000000000123123123123',
+                denom: 'utoken',
+            });
+        });
+
         it('throws for non-safe-integer values', function () {
             expect(() => coin('1.23', 'utoken')).to.throw();
             expect(() => coin('123.0', 'utoken')).to.throw();
             expect(() => coin('NaN', 'utoken')).to.throw();
             expect(() => coin(Number.POSITIVE_INFINITY.toString(), 'utoken')).to.throw();
-            expect(() => coin((Number.MAX_SAFE_INTEGER + 1).toString(), 'utoken')).to.throw();
+            expect(() => coin((Number.MAX_SAFE_INTEGER + 1).toString(), 'utoken')).to.not.throw();
         });
 
         it('throws for negative values', function () {

lib/src/cosmos/coins.ts

@@ -1,4 +1,10 @@
-import { Uint53 } from '@cosmjs/math';
+import { Big } from 'big.js';
+
+// Decimal places
+Big.DP = 100;
+
+// Precision quantity after exponent format starts
+Big.PE = 100;
 
 export interface Coin {
     readonly denom: string;
@@ -7,7 +13,13 @@ export interface Coin {
 
 /** Creates a coin */
 export function coin(amount: string, denom: string): Coin {
-    return { amount: Uint53.fromString(amount).toString(), denom };
+    const amountInBN = new Big(amount);
+
+    // Disallow decimal and negative integers
+    if (amountInBN.cmp(0) === -1 || amount.includes('.')) {
+        throw new Error('Invalid amount string.');
+    }
+    return { amount: amountInBN.toString(), denom };
 }
 
 /** Creates a list of coins with one element */