Fix: Support converting small number to AmountTokenV2

CHANGELOG.md

@@ -13,6 +13,7 @@
 - Add retrieveBtcStatus to ckbtc minter canister.
 - Make uint8ArrayToHexString also accept `number[]` as input.
 - Add a new type TokenAmountV2 which supports `decimals !== 8`.
+- Fix issue when converting token amount from small numbers with `TokenAmountV2`.
 
 ## Operations
 

package.json

@@ -97,7 +97,7 @@
     {
       "name": "@dfinity/ledger-icp",
       "path": "./packages/ledger-icp/dist/index.js",
-      "limit": "15 kB",
+      "limit": "16 kB",
       "ignore": [
         "@dfinity/agent",
         "@dfinity/candid",

packages/utils/README.md

@@ -74,7 +74,7 @@ Parameters:
 
 - `amount`: - in string format
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L10)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L12)
 
 #### :gear: defaultAgent
 
@@ -376,15 +376,15 @@ Tags after patch version are ignored, e.g. 1.0.0-beta.1 is considered equal to 1
 | ---------- | ------- |
 | `ICPToken` | `Token` |
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L113)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L115)
 
 ### :factory: TokenAmount
 
 Deprecated. Use TokenAmountV2 instead which supports decimals !== 8.
 
 Represents an amount of tokens.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L127)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L129)
 
 #### Methods
 
@@ -406,7 +406,7 @@ Parameters:
 - `params.amount`: The amount in bigint format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L144)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L146)
 
 ##### :gear: fromString
 
@@ -425,7 +425,7 @@ Parameters:
 - `params.amount`: The amount in string format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L165)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L167)
 
 ##### :gear: fromNumber
 
@@ -442,21 +442,21 @@ Parameters:
 - `params.amount`: The amount in number format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L195)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L197)
 
 ##### :gear: toE8s
 
 | Method  | Type           |
 | ------- | -------------- |
 | `toE8s` | `() => bigint` |
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L221)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L223)
 
 ### :factory: TokenAmountV2
 
 Represents an amount of tokens.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L233)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L235)
 
 #### Methods
 
@@ -478,7 +478,7 @@ Parameters:
 - `params.amount`: The amount in bigint format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L246)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L248)
 
 ##### :gear: fromString
 
@@ -497,7 +497,7 @@ Parameters:
 - `params.amount`: The amount in string format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L267)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L269)
 
 ##### :gear: fromNumber
 
@@ -514,15 +514,15 @@ Parameters:
 - `params.amount`: The amount in number format.
 - `params.token`: The token type.
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L291)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L293)
 
 ##### :gear: toUlps
 
 | Method   | Type           |
 | -------- | -------------- |
 | `toUlps` | `() => bigint` |
 
-[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L319)
+[:link: Source](https://github.com/dfinity/ic-js/tree/main/packages/utils/src/parser/token.ts#L321)
 
 ### :factory: Canister
 

packages/utils/src/parser/token.spec.ts

@@ -336,13 +336,9 @@ describe("TokenAmountV2 with 18 decimals", () => {
     ).toBe(FromStringToTokenError.InvalidFormat);
   });
 
-  it("does not support scientific notation", () => {
-    const callToNumber = () =>
-      TokenAmountV2.fromNumber({ token: token, amount: 1e-9 });
-    expect(callToNumber).toThrow(
-      expect.objectContaining({
-        message: "Invalid number 1e-9",
-      }),
+  it("does not support scientific notation as string", () => {
+    expect(TokenAmountV2.fromString({ token: token, amount: "1e-9" })).toEqual(
+      FromStringToTokenError.InvalidFormat,
     );
   });
 
@@ -433,3 +429,47 @@ describe("TokenAmountV2 with 0 decimals", () => {
     ).toEqual(FromStringToTokenError.FractionalTooManyDecimals);
   });
 });
+
+describe("TokenAmountV2 with 8 decimals", () => {
+  const token = {
+    symbol: "ICP",
+    name: "ICP",
+    decimals: 8,
+  };
+  it("can be initialized from a number", () => {
+    expect(TokenAmountV2.fromNumber({ token: token, amount: 1 })).toEqual(
+      TokenAmountV2.fromUlps({
+        token: token,
+        amount: 100000000n,
+      }),
+    );
+    expect(TokenAmountV2.fromNumber({ token: token, amount: 1234 })).toEqual(
+      TokenAmountV2.fromUlps({
+        token: token,
+        amount: 123400000000n,
+      }),
+    );
+    expect(
+      TokenAmountV2.fromNumber({ token: token, amount: 0.00000002 }),
+    ).toEqual(
+      TokenAmountV2.fromUlps({
+        token: token,
+        amount: 2n,
+      }),
+    );
+    expect(
+      TokenAmountV2.fromNumber({ token: token, amount: 0.00000001 }),
+    ).toEqual(
+      TokenAmountV2.fromUlps({
+        token: token,
+        amount: 1n,
+      }),
+    );
+  });
+
+  it("truncates small numbers to 8 decimals", () => {
+    expect(TokenAmountV2.fromNumber({ token: token, amount: 1e-9 })).toEqual(
+      TokenAmountV2.fromUlps({ token: token, amount: 0n }),
+    );
+  });
+});

packages/utils/src/parser/token.ts

@@ -1,6 +1,8 @@
 import { E8S_PER_TOKEN } from "../constants/constants";
 import { FromStringToTokenError } from "../enums/token.enums";
 
+const DECIMALS_CONVERSION_SUPPORTED = 8;
+
 /**
  * Receives a string representing a number and returns the big int or error.
  *
@@ -296,7 +298,7 @@ export class TokenAmountV2 {
     token: Token;
   }): TokenAmountV2 {
     const tokenAmount = TokenAmountV2.fromString({
-      amount: amount.toString(),
+      amount: amount.toFixed(DECIMALS_CONVERSION_SUPPORTED),
       token,
     });
     if (tokenAmount instanceof TokenAmountV2) {