(Fix) Error when using up to the max amount of decimals for token transfer (#1576)

src/logic/tokens/utils/__tests__/tokenHelpers.test.ts

@@ -203,4 +203,32 @@ describe('isERC721Contract', () => {
     // then
     expect(txValue).toEqual(expectedResult)
   })
+
+  it('It should return the right conversion from token to unit with exceeding decimals', () => {
+    // given
+    const decimals = Number(18)
+
+    const expectedResult = '333333333333333398'
+    const VALUE = '0.33333333333333339878798333'
+
+    // when
+    const txValue = toTokenUnit(VALUE, decimals)
+
+    // then
+    expect(txValue).toEqual(expectedResult)
+  })
+
+  it('It should return the right conversion from token to unit with exact decimals', () => {
+    // given
+    const decimals = Number(18)
+
+    const expectedResult = '333333333333333399'
+    const VALUE = '0.333333333333333399'
+
+    // when
+    const txValue = toTokenUnit(VALUE, decimals)
+
+    // then
+    expect(txValue).toEqual(expectedResult)
+  })
 })

src/logic/tokens/utils/humanReadableValue.ts

@@ -7,13 +7,5 @@ export const humanReadableValue = (value: number | string, decimals = 18): strin
 export const fromTokenUnit = (amount: number | string, decimals: string | number): string =>
   new BigNumber(amount).times(`1e-${decimals}`).toFixed()
 
-export const toTokenUnit = (amount: number | string, decimals: string | number): string => {
+export const toTokenUnit = (amount: number | string, decimals: string | number): string =>
-  const amountBN = new BigNumber(amount).times(`1e${decimals}`)
+  new BigNumber(amount).times(`1e${decimals}`).toFixed(0, BigNumber.ROUND_DOWN)
-  const [, amountDecimalPlaces] = amount.toString().split('.')
-
-  if (amountDecimalPlaces?.length >= +decimals) {
-    return amountBN.toFixed(+decimals, BigNumber.ROUND_DOWN)
-  }
-
-  return amountBN.toFixed()
-}