From b7add122fa60162efd7d3b8f45c581581eeacee3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Jos=C3=A9=20Ram=C3=ADrez?= <artjjrn@gmail.com>
Date: Mon, 4 Nov 2024 09:11:15 -0300
Subject: [PATCH 1/2] fix: use normalized decimal count for fromAmount
 calculation

---
 src/util.ts            |  2 +-
 test/unit/util.test.ts | 56 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/util.ts b/src/util.ts
index 9c5f72e..3134336 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -742,7 +742,7 @@ export async function prepareXchainFromAmountCalculation({
 		const slippageFractionBN = ethers.BigNumber.from(Math.floor(slippagePercentage * 1000))
 		const slippageBN = fromAmountBN.mul(slippageFractionBN).div(100000) // 1000 * 100 (10e5)
 		const totalFromAmountBN = fromAmountBN.add(slippageBN)
-		return ethers.utils.formatUnits(totalFromAmountBN, fromToken.decimals)
+		return Number(ethers.utils.formatUnits(totalFromAmountBN, normalizedDecimalCount)).toFixed(fromToken.decimals)
 	} catch (error) {
 		console.error('Failed to calculate fromAmount:', error)
 		return null
diff --git a/test/unit/util.test.ts b/test/unit/util.test.ts
index c84509e..0b3fc8f 100644
--- a/test/unit/util.test.ts
+++ b/test/unit/util.test.ts
@@ -1,4 +1,6 @@
-import { normalizePath } from '../../src/util'
+import { normalizePath, prepareXchainFromAmountCalculation } from '../../src/util'
+
+const mockFetch = jest.fn()
 
 describe('util', () => {
 	describe('normalizePath', () => {
@@ -14,4 +16,56 @@ describe('util', () => {
 			expect(normalizePath(url)).toBe(normalizedUrl)
 		})
 	})
+
+	describe('prepareXchainFromAmountCalculation', () => {
+		beforeEach(() => {
+			jest.spyOn(global, 'fetch').mockImplementation(mockFetch)
+		})
+
+		afterEach(() => {
+			jest.restoreAllMocks()
+			jest.clearAllMocks()
+		})
+		it('should return price with correct decimals', async () => {
+			const fromToken = {
+				chainId: '534352',
+				address: '0x06efdbff2a14a7c8e15944d1f4a48f9f95f663a4',
+				decimals: 6,
+			}
+			const toToken = {
+				chainId: '8453',
+				address: '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE',
+				decimals: 18,
+			}
+			const fromTokenPrice = 0.999842
+			const toTokenPrice = 2453.66
+			const toAmount = '0.00408'
+			const expectedFromAmount = '10.042552'
+			const slippagePercentage = 0.3
+			mockFetch.mockImplementation((url: string) => {
+				const tokenAddress = new URL(url).searchParams.get('tokenAddress')
+				let price: number
+				if (tokenAddress === fromToken.address) {
+					price = fromTokenPrice
+				} else if (tokenAddress === toToken.address) {
+					price = toTokenPrice
+				} else {
+					price = 0
+				}
+				return Promise.resolve({
+					json: () => Promise.resolve({ price }),
+				})
+			})
+
+			const fromAmount = await prepareXchainFromAmountCalculation({
+				fromToken,
+				toToken,
+				toAmount,
+				slippagePercentage,
+			})
+
+			expect(mockFetch).toHaveBeenCalledTimes(2)
+			expect(fromAmount).toBe(expectedFromAmount)
+		})
+	})
 })

From a3f52056e7c9be6a7e38d3b38d9ac023dd627cd7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Jos=C3=A9=20Ram=C3=ADrez?= <artjjrn@gmail.com>
Date: Mon, 4 Nov 2024 11:34:11 -0300
Subject: [PATCH 2/2] refactor: fix decimals in estimateFromAmount with regex

---
 src/util.ts            | 12 +++++++++++-
 test/unit/util.test.ts | 15 ++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/util.ts b/src/util.ts
index 3134336..7639d27 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -742,7 +742,8 @@ export async function prepareXchainFromAmountCalculation({
 		const slippageFractionBN = ethers.BigNumber.from(Math.floor(slippagePercentage * 1000))
 		const slippageBN = fromAmountBN.mul(slippageFractionBN).div(100000) // 1000 * 100 (10e5)
 		const totalFromAmountBN = fromAmountBN.add(slippageBN)
-		return Number(ethers.utils.formatUnits(totalFromAmountBN, normalizedDecimalCount)).toFixed(fromToken.decimals)
+		const amount = ethers.utils.formatUnits(totalFromAmountBN, normalizedDecimalCount)
+		return stringToFixed(amount, fromToken.decimals)
 	} catch (error) {
 		console.error('Failed to calculate fromAmount:', error)
 		return null
@@ -759,3 +760,12 @@ export function normalizePath(url: string): string {
 		return url.replace(/\/+/g, '/')
 	}
 }
+
+export function stringToFixed(numStr: string, precision: number = 0): string {
+	const match = numStr.match(/^(-?\d+)\.(?<decimals>\d*)$/)
+	if (!match) return numStr
+
+	const [_, intPart, decimals] = match
+	const rounded = decimals.padEnd(precision, '0').slice(0, precision)
+	return rounded ? `${intPart}.${rounded}` : intPart
+}
diff --git a/test/unit/util.test.ts b/test/unit/util.test.ts
index 0b3fc8f..2b86c95 100644
--- a/test/unit/util.test.ts
+++ b/test/unit/util.test.ts
@@ -1,4 +1,4 @@
-import { normalizePath, prepareXchainFromAmountCalculation } from '../../src/util'
+import { normalizePath, prepareXchainFromAmountCalculation, stringToFixed } from '../../src/util'
 
 const mockFetch = jest.fn()
 
@@ -68,4 +68,17 @@ describe('util', () => {
 			expect(fromAmount).toBe(expectedFromAmount)
 		})
 	})
+
+	describe('stringToFixed', () => {
+		it.each([
+			['0.001', '0.00', 2],
+			['0.01', '0.01', 2],
+			['0.1', '0.10', 2],
+			['1', '1', 2],
+			['10.1', '10.10', 2],
+			['10.123456', '10.123', 3],
+		])('should convert %s to %s with precision %s', (numStr, expected, precision) => {
+			expect(stringToFixed(numStr, precision)).toBe(expected)
+		})
+	})
 })