Merge pull request #923 from cosmos/let-coin-support-strings

Let coin/coins take amount as number | string

CHANGELOG.md

@@ -6,6 +6,12 @@ and this project adheres to
 
 ## [Unreleased]
 
+### Added
+
+- @cosmjs/amino: The `coin` and `coins` helpers now support both `number` and
+  `string` as input types for the amount. This is useful if your values exceed
+  the safe integer range.
+
 ## [0.26.4] - 2021-10-28
 
 ### Fixed

packages/amino/src/coins.spec.ts

@@ -2,7 +2,7 @@ import { coin, coins, parseCoins } from "./coins";
 
 describe("coins", () => {
   describe("coin", () => {
-    it("works for basic values", () => {
+    it("works for number amounts", () => {
       expect(coin(123, "utoken")).toEqual({ amount: "123", denom: "utoken" });
       expect(coin(123.0, "utoken")).toEqual({ amount: "123", denom: "utoken" });
       expect(coin(Number.MAX_SAFE_INTEGER, "utoken")).toEqual({
@@ -14,22 +14,56 @@ describe("coins", () => {
     });
 
     it("throws for non-safe-integer values", () => {
-      expect(() => coin(1.23, "utoken")).toThrow();
-      expect(() => coin(NaN, "utoken")).toThrow();
-      expect(() => coin(Number.POSITIVE_INFINITY, "utoken")).toThrow();
-      expect(() => coin(Number.MAX_SAFE_INTEGER + 1, "utoken")).toThrow();
+      expect(() => coin(1.23, "utoken")).toThrowError(/Given amount is not a safe integer/i);
+      expect(() => coin(NaN, "utoken")).toThrowError(/Given amount is not a safe integer/i);
+      expect(() => coin(Number.POSITIVE_INFINITY, "utoken")).toThrowError(
+        /Given amount is not a safe integer/i,
+      );
+      expect(() => coin(Number.MAX_SAFE_INTEGER + 1, "utoken")).toThrowError(
+        /Given amount is not a safe integer/i,
+      );
     });
 
     it("throws for negative values", () => {
-      expect(() => coin(-1, "utoken")).toThrow();
-      expect(() => coin(Number.MIN_SAFE_INTEGER, "utoken")).toThrow();
-      expect(() => coin(Number.NEGATIVE_INFINITY, "utoken")).toThrow();
+      expect(() => coin(-1, "utoken")).toThrowError(/Given amount is not a safe integer/i);
+      expect(() => coin(Number.MIN_SAFE_INTEGER, "utoken")).toThrowError(
+        /Given amount is not a safe integer/i,
+      );
+      expect(() => coin(Number.NEGATIVE_INFINITY, "utoken")).toThrowError(
+        /Given amount is not a safe integer/i,
+      );
+    });
+
+    it("works for string amounts", () => {
+      expect(coin("0", "utoken")).toEqual({ amount: "0", denom: "utoken" });
+      expect(coin("1", "utoken")).toEqual({ amount: "1", denom: "utoken" });
+      expect(coin("00123", "utoken")).toEqual({ amount: "123", denom: "utoken" });
+      expect(coin("12300", "utoken")).toEqual({ amount: "12300", denom: "utoken" });
+      expect(coin("9007199254740992", "utoken")).toEqual({ amount: "9007199254740992", denom: "utoken" });
+      // ETH supply (~118 mio ETH)
+      expect(coin("118273505060000000000000000", "wei")).toEqual({
+        amount: "118273505060000000000000000",
+        denom: "wei",
+      });
+    });
+
+    it("throws for invalid amount strings", () => {
+      expect(() => coin("-1", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin("0x01", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin("NaN", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin("1.0", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin("1 ", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin(" 1", "utoken")).toThrowError(/Invalid unsigned integer string format/i);
+      expect(() => coin("1.1827350506e+26", "utoken")).toThrowError(
+        /Invalid unsigned integer string format/i,
+      );
     });
   });
 
   describe("coins", () => {
     it("returns one element array of coin", () => {
       expect(coins(123, "utoken")).toEqual([{ amount: "123", denom: "utoken" }]);
+      expect(coins("123", "utoken")).toEqual([{ amount: "123", denom: "utoken" }]);
     });
   });
 

packages/amino/src/coins.ts

@@ -7,15 +7,39 @@ export interface Coin {
 
 /**
  * Creates a coin.
+ *
+ * If your values do not exceed the safe integer range of JS numbers (53 bit),
+ * you can use the number type here. This is the case for all typical Cosmos SDK
+ * chains that use the default 6 decimals.
+ *
+ * In case you need to supportr larger values, use unsigned integer strings instead.
  */
-export function coin(amount: number, denom: string): Coin {
-  return { amount: new Uint53(amount).toString(), denom: denom };
+export function coin(amount: number | string, denom: string): Coin {
+  let outAmount: string;
+  if (typeof amount === "number") {
+    try {
+      outAmount = new Uint53(amount).toString();
+    } catch (_err) {
+      throw new Error(
+        "Given amount is not a safe integer. Consider using a string instead to overcome the limitations of JS numbers.",
+      );
+    }
+  } else {
+    if (!amount.match(/^[0-9]+$/)) {
+      throw new Error("Invalid unsigned integer string format");
+    }
+    outAmount = amount.replace(/^0*/, "") || "0";
+  }
+  return {
+    amount: outAmount,
+    denom: denom,
+  };
 }
 
 /**
  * Creates a list of coins with one element.
  */
-export function coins(amount: number, denom: string): Coin[] {
+export function coins(amount: number | string, denom: string): Coin[] {
   return [coin(amount, denom)];
 }