fix(#7044): toWei trim strings with more than 20 decimal places (#7045)

* fix(#7044): fix too many decimals passed to toWei

* add test case

* add tests and fix fromWei

* add changelog and update tests

* update test

---------

Co-authored-by: Alex Luu <alex.luu@mail.utoronto.ca>

Author: gordon-to

packages/web3-utils/CHANGELOG.md

@@ -224,4 +224,5 @@ Documentation:
 
 ### Fixed
 
-- `toWei` support numbers in scientific notation (#6908)
+- `toWei` support numbers in scientific notation (#6908)
+- `toWei` and `fromWei` trims according to ether unit successfuly (#7044)

packages/web3-utils/src/converters.ts

@@ -532,8 +532,9 @@ export const fromWei = (number: Numbers, unit: EtherUnits): string => {
 	if (fraction === '') {
 		return integer;
 	}
+	const updatedValue = `${integer}.${fraction}`;
 
-	return `${integer}.${fraction}`;
+	return updatedValue.slice(0, integer.length + numberOfZerosInDenomination + 1);
 };
 
 /**
@@ -559,50 +560,50 @@ export const toWei = (number: Numbers, unit: EtherUnits): string => {
 		throw new InvalidUnitError(unit);
 	}
 	let parsedNumber = number;
-	if (typeof parsedNumber === 'number'){
-		if (parsedNumber  < 1e-15){
-			console.warn(PrecisionLossWarning)
+	if (typeof parsedNumber === 'number') {
+		if (parsedNumber < 1e-15) {
+			console.warn(PrecisionLossWarning);
 		}
-		if (parsedNumber > 1e+20) {
-			console.warn(PrecisionLossWarning)
+		if (parsedNumber > 1e20) {
+			console.warn(PrecisionLossWarning);
 
-			parsedNumber =  BigInt(parsedNumber);
+			parsedNumber = BigInt(parsedNumber);
 		} else {
 			// in case there is a decimal point, we need to convert it to string
-			parsedNumber = parsedNumber.toLocaleString('fullwide', {useGrouping: false, maximumFractionDigits: 20})
+			parsedNumber = parsedNumber.toLocaleString('fullwide', {
+				useGrouping: false,
+				maximumFractionDigits: 20,
+			});
 		}
 	}
-	
+
 	// if value is decimal e.g. 24.56 extract `integer` and `fraction` part
 	// to avoid `fraction` to be null use `concat` with empty string
 	const [integer, fraction] = String(
-		typeof parsedNumber === 'string' && !isHexStrict(parsedNumber) ? parsedNumber : toNumber(parsedNumber),
+		typeof parsedNumber === 'string' && !isHexStrict(parsedNumber)
+			? parsedNumber
+			: toNumber(parsedNumber),
 	)
 		.split('.')
 		.concat('');
 
 	// join the value removing `.` from
 	// 24.56 -> 2456
-	
+
 	const value = BigInt(`${integer}${fraction}`);
 
 	// multiply value with denomination
 	// 2456 * 1000000 -> 2456000000
 	const updatedValue = value * denomination;
 
-	// count number of zeros in denomination
-	const numberOfZerosInDenomination = denomination.toString().length - 1;
-
-	// check which either `fraction` or `denomination` have lower number of zeros
-	const decimals = Math.min(fraction.length, numberOfZerosInDenomination);
-
+	// check if whole number was passed in
+	const decimals = fraction.length;
 	if (decimals === 0) {
 		return updatedValue.toString();
 	}
 
-	// Add zeros to make length equal to required decimal points
-	// If string is larger than decimal points required then remove last zeros
-	return updatedValue.toString().padStart(decimals, '0').slice(0, -decimals);
+	// trim the value to remove extra zeros
+	return updatedValue.toString().slice(0, -decimals);
 };
 
 /**

packages/web3-utils/test/fixtures/converters.ts

@@ -292,20 +292,30 @@ const conversionBaseData: [[Numbers, EtherUnits], string][] = [
 	[['879123456788877661', 'tether'], '0.000000000000879123456788877661'],
 ];
 
-export const fromWeiValidData: [[Numbers, EtherUnits], string][] = [
+export const fromWeiValidData: [[Numbers, EtherUnits], Numbers][] = [
 	...conversionBaseData,
     [['0xff', 'wei'], '255'],
     [[1e+22, 'ether'], '10000'],
     [[19999999999999991611392, 'ether'], '19999.999999999991611392'],
     [[1.9999999999999991611392e+22, 'ether'], '19999.999999999991611392'],
+	[['1000000', 'ether'], '0.000000000001'],
+	[['1123456789123456789', 'ether'], '1.123456789123456789'],
+	[['1123', 'kwei'], '1.123'],
+	[['1234100' ,'kwei'], '1234.1'],
+	[['3308685546611893', 'ether'], '0.003308685546611893']
 ];
 
 export const toWeiValidData: [[Numbers, EtherUnits], Numbers][] = [
 	...conversionBaseData,
 	[['255', 'wei'], '0xFF'],
 	[['100000000000', 'ether'], 0.0000001],
 	[['1000000000', 'ether'], 0.000000001],
-	[['1000000', 'ether'], 0.000000000001]
+	[['1000000', 'ether'], 0.000000000001],
+	[['1123456789123456789', 'ether'], '1.123456789123456789123'],
+	[['1123', 'kwei'], '1.12345'],
+	[['1234100' ,'kwei'], '1234.1'],
+	[['3308685546611893', 'ether'], '0.0033086855466118933'],
+	[['1123', 'kwei'], 1.12345],
 
 ];