meterify.utils

This package provides utility functions for dapps and other packages.
randomHex
    meterify.utils.randomHex(size)
The randomHex library to generate cryptographically strong pseudo-random HEX strings from a given byte size.
Example:
​
    meterify.utils.randomHex(32)
    > "0xa5b9d60f32436310afebcfda832817a68921beb782fabf7915cc0460b443116a"
​
    meterify.utils.randomHex(4)
    > "0x6892ffc6"
​
    meterify.utils.randomHex(2)
    > "0x99d6"
​
    meterify.utils.randomHex(1)
    > "0x9a"
​
    meterify.utils.randomHex(0)
    > "0x"
Parameters:
size - Number: The byte size for the HEX string, e.g. 32 will result in a 32 bytes HEX string with 64 characters preficed with "0x".
Returns:
String: The generated random HEX string.
BN    
meterify.utils.BN(mixed)
The BN.js library for calculating with big numbers in JavaScript. See the BN.js documentation for details.
Example:
​
    const BN = meterify.utils.BN;
​
    new BN(1234).toString();
    > "1234"
​
    new BN('1234').add(new BN('1')).toString();
    > "1235"
​
    new BN('0xea').toString();
    > "234"
Note: For safe conversion of many types, including BigNumber.js, use utils.toBN.
Parameters:
value - String|Number: A number, number string or HEX string to convert to a BN object.
Returns:
Object: The BN.js_ instance.
isBN
​
    meterify.utils.isBN(bn)
Checks if a given value is a BN.js instance.
Example:
​
    const number = new BN(10);
​
    meterify.utils.isBN(number);
    > true
Parameters:
bn - Object: An BN.js instance.
Returns:
Boolean
isBigNumber
    meterify.utils.isBigNumber(bignumber)
Checks if a given value is a BigNumber.js instance.
Example:
​
    const number = new BigNumber(10);
​
    meterify.utils.isBigNumber(number);
    > true
Parameters:
BigNumber - Object: A BigNumber.js instance.
Returns:
Boolean
keccak256
​
    meterify.utils.keccak256(string)
    meterify.utils.sha3(string) // ALIAS
Will calculate the keccak256 of the input.
Example:
​
    meterify.utils.keccak256('234'); // taken as string
    > "0xc1912fee45d61c87cc5ea59dae311904cd86b84fee17cc96966216f811ce6a79"
​
    meterify.utils.keccak256(new BN('234'));
    > "0xbc36789e7a1e281436464229828f817d6612f7b477d66591ff96a9e064bcc98a"
​
    meterify.utils.keccak256(234);
    > null // can't calculate the hash of a number
​
    meterify.utils.keccak256(0xea); // same as above, just the HEX representation of the number
    > null
​
    meterify.utils.keccak256('0xea'); // will be converted to a byte array first, and then hashed
    > "0x2f20677459120677484f7104c76deb6846a2c071f9b3152c103bb12cd54d1a4a"
Note: To mimic the keccak256 behavior of Solidity, use soliditySha3.
Parameters:
string - String: A string to hash.
Returns:
String: the result hash.
soliditySha3    
meterify.utils.soliditySha3(param1 [, param2, ...])
Will calculate the sha3 of given input parameters in the same way solidity would. This means arguments will be ABI converted and tightly packed before being hashed.
Example:
meterify.utils.soliditySha3('234564535', '0xfff23243', true, -10);
    // auto detects:        uint256,      bytes,     bool,   int256
    > "0x3e27a893dc40ef8a7f0841d96639de2f58a132be5ae466d40087a2cfa83b7179"
​
    meterify.utils.soliditySha3('Hello!%'); // auto detects: string
    > "0x661136a4267dba9ccdf6bfddb7c00e714de936674c4bdb065a531cf1cb15c7fc"
​
    meterify.utils.soliditySha3('234'); // auto detects: uint256
    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
​
    meterify.utils.soliditySha3(0xea); // same as above
    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
​
    meterify.utils.soliditySha3(new BN('234')); // same as above
    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
​
    meterify.utils.soliditySha3({type: 'uint256', value: '234'})); // same as above
    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
​
    meterify.utils.soliditySha3({t: 'uint', v: new BN('234')})); // same as above
    > "0x61c831beab28d67d1bb40b5ae1a11e2757fa842f031a2d0bc94a7867bc5d26c2"
​
    meterify.utils.soliditySha3('0x407D73d8a49eeb85D32Cf465507dd71d507100c1');
    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b"
​
    meterify.utils.soliditySha3({t: 'bytes', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b" // same result as above
​
    meterify.utils.soliditySha3({t: 'address', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
    > "0x4e8ebbefa452077428f93c9520d3edd60594ff452a29ac7d2ccc11d47f3ab95b" // same as above, but will do a checksum check, if its multi case
​
    meterify.utils.soliditySha3({t: 'bytes32', v: '0x407D73d8a49eeb85D32Cf465507dd71d507100c1'});
    > "0x3c69a194aaf415ba5d6afca734660d0a3d45acdc05d54cd1ca89a8988e7625b4" // different result as above
​
    meterify.utils.soliditySha3({t: 'string', v: 'Hello!%'}, {t: 'int8', v:-23}, {t: 'address', v: '0x85F43D8a49eeB85d32Cf465507DD71d507100C1d'});
    > "0xa13b31627c1ed7aaded5aecec71baf02fe123797fffd45e662eac8e06fbe4955"
Parameters:
paramX - Mixed: Any type, or an object with {type: 'uint', value: '123456'} or {t: 'bytes', v: '0xfff456'}. Basic types are autodetected as follows:
String non numerical UTF-8 string is interpreted as string.
String|Number|BN|HEX positive number is interpreted as uint256.
String|Number|BN negative number is interpreted as int256. 
Boolean as bool. 
String HEX string with leading 0x is interpreted as bytes. 
HEX HEX number representation is interpreted as uint256.
Returns:
String: the result hash.
isHex    
meterify.utils.isHex(hex)
Checks if a given string is a HEX string.
Example:
    meterify.utils.isHex('0xc1912');
    > true
​
    meterify.utils.isHex(0xc1912);
    > true
​
    meterify.utils.isHex('c1912');
    > true
​
    meterify.utils.isHex(345);
    > true // this is tricky, as 345 can be a a HEX representation or a number, be careful when not having a 0x in front!
​
    meterify.utils.isHex('0xZ1912');
    > false
​
    meterify.utils.isHex('Hello');
    > false
Parameters:
hex - String|HEX: The given HEX string.
Returns:
Boolean
isHexStrict    
meterify.utils.isHexStrict(hex)
Checks if a given string is a HEX string. Difference to meterify.utils.isHex() is that it expects HEX to be prefixed with 0x.
Example:
    meterify.utils.isHexStrict('0xc1912');
    > true
​
    meterify.utils.isHexStrict(0xc1912);
    > false
​
    meterify.utils.isHexStrict('c1912');
    > false
​
    meterify.utils.isHexStrict(345);
    > false // this is tricky, as 345 can be a a HEX representation or a number, be careful when not having a 0x in front!
​
    meterify.utils.isHexStrict('0xZ1912');
    > false
​
    meterify.utils.isHex('Hello');
    > false
Parameters:
hex - String|HEX: The given HEX string.
Returns:
Boolean
isAddress    
meterify.utils.isAddress(address,  [, chainId])
Checks if a given string is a valid Meter address. It will also check the checksum, if the address has upper and lowercase letters.
Example:
    meterify.utils.isAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');
    > true
​
    meterify.utils.isAddress('c1912fee45d61c87cc5ea59dae31190fffff232d');
    > true
​
    meterify.utils.isAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D');
    > true // as all is uppercase, no checksum will be checked
​
    meterify.utils.isAddress('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
    > true
​
    meterify.utils.isAddress('0xC1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
    > false // wrong checksum
​
    meterify.utils.isAddress('0x5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD', 30);
    > true
Parameters:
address - String: An address string.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
Boolean
toChecksumAddress
    meterify.utils.toChecksumAddress(address[, chainId])
Will convert an upper or lowercase Meter address to a checksum address.
Example:
​
    meterify.utils.toChecksumAddress('0xc1912fee45d61c87cc5ea59dae31190fffff232d');
    > "0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d"
​
    meterify.utils.toChecksumAddress('0XC1912FEE45D61C87CC5EA59DAE31190FFFFF232D');
    > "0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d" // same as above
​
    meterify.utils.toChecksumAddress('0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed', 30);
    > "0x5aaEB6053f3e94c9b9a09f33669435E7ef1bEAeD"
Parameters:
address - String: An address string.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
String: The checksum address.
stripHexPrefix
     meterify.utils.stripHexPrefix(address)
Removes the prefix 0x from a given hex if it exists.
Example:
      meterify.utils.stripHexPrefix('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
     > "c1912fEE45d61C87Cc5EA59DaE31190FFFFf232d"
Parameters:
hex - String: Hex
Returns:
String: Hex without prefix.
checkAddressChecksum
​
    meterify.utils.checkAddressChecksum(address [, chainId])
Checks the checksum of a given address. Will also return false on non-checksum addresses.
Example:
​
    meterify.utils.checkAddressChecksum('0xc1912fEE45d61C87Cc5EA59DaE31190FFFFf232d');
    > true
​
    meterify.utils.checkAddressChecksum('0x5aAeb6053F3e94c9b9A09F33669435E7EF1BEaEd', 31);
    > true
Parameters:
address - String: An address string.
chainId - number (optional): Chain id where checksummed address should be valid, defaults to null. RSKIP-60 for details.
Returns:
Boolean: true when the checksum of the address is valid, false if its not a checksum address, or the checksum is invalid.
toHex
​
    meterify.utils.toHex(mixed)
Will auto convert any given value to HEX. Number strings will interpreted as numbers. Text strings will be interpreted as UTF-8 strings.
Example:
​
    meterify.utils.toHex('234');
    > "0xea"
​
    meterify.utils.toHex(234);
    > "0xea"
​
    meterify.utils.toHex(new BN('234'));
    > "0xea"
​
    meterify.utils.toHex(new BigNumber('234'));
    > "0xea"
​
    meterify.utils.toHex('I have 100€');
    > "0x49206861766520313030e282ac"
Parameters:
value - String|Number|BN|BigNumber: The input to convert to HEX.
Returns:
String: The resulting HEX string.
toBN    
meterify.utils.toBN(number)
Will safely convert any given value (including BigNumber.js instances) into a BN.js instance, for handling big numbers in JavaScript.
Example:
​
    meterify.utils.toBN(1234).toString();
    > "1234"
​
    meterify.utils.toBN('1234').add(meterify.utils.toBN('1')).toString();
    > "1235"
​
    meterify.utils.toBN('0xea').toString();
    > "234"
Note: For just the BN.js class use utils.BN.
Parameters:
number - String|Number|HEX: Number to convert to a big number.
Returns:
Object: The BN.js instance.
hexToNumberString
    meterify.utils.hexToNumberString(hex)
Returns the number representation of a given HEX value as a string.
Example:
    meterify.utils.hexToNumberString('0xea');
    > "234"
Parameters:
hexString - String|HEX: A string to hash.
Returns:
String: The number as a string.
hexToNumber
​
    meterify.utils.hexToNumber(hex)
    meterify.utils.toDecimal(hex) // ALIAS, deprecated
Returns the number representation of a given HEX value.
Example:
​
    meterify.utils.hexToNumber('0xea');
    > 234
Note: This is not useful for big numbers, use utils.toBN instead.
Parameters:
hexString - String|HEX: A string to hash.
Returns:
Number
numberToHex
​
    meterify.utils.numberToHex(number)
    meterify.utils.fromDecimal(number) // ALIAS, deprecated
Returns the HEX representation of a given number value.
Example:
​
    meterify.utils.numberToHex('234');
    > '0xea'
Parameters:
number - String|Number|BN|BigNumber: A number as string or number.
Returns:
String: The HEX value of the given number.
hexToUtf8
​
    meterify.utils.hexToUtf8(hex)
    meterify.utils.hexToString(hex) // ALIAS
    meterify.utils.toUtf8(hex) // ALIAS, deprecated
Returns the UTF-8 string representation of a given HEX value.
Example:
​
    meterify.utils.hexToUtf8('0x49206861766520313030e282ac');
    > "I have 100€"
Parameters:
hex - String: A HEX string to convert to a UTF-8 string.
Returns:
String: The UTF-8 string.
hexToAscii
​
    meterify.utils.hexToAscii(hex)
    meterify.utils.toAscii(hex) // ALIAS, deprecated
Returns the ASCII string representation of a given HEX value.
Example:
​
    meterify.utils.hexToAscii('0x4920686176652031303021');
    > "I have 100!"
Parameters:
hex - String: A HEX string to convert to a ASCII string.
Returns:
String: The ASCII string.
utf8ToHex    
    meterify.utils.utf8ToHex(string)
    meterify.utils.stringToHex(string) // ALIAS
    meterify.utils.fromUtf8(string) // ALIAS, deprecated
Returns the HEX representation of a given UTF-8 string.
Example:
    meterify.utils.utf8ToHex('I have 100€');
    > "0x49206861766520313030e282ac"
Parameters:
string - String: A UTF-8 string to convert to a HEX string.
Returns:
String: The HEX string.
asciiToHex   
    meterify.utils.asciiToHex(string)
    meterify.utils.fromAscii(string) // ALIAS, deprecated
Returns the HEX representation of a given ASCII string. If you would like to transform an ASCII string into a valid bytes4, bytes8 etc. value then please pass the correct length as the second parameter.
Example:
    meterify.utils.asciiToHex('I have 100!');
    > "0x4920686176652031303021000000000000000000000000000000000000000000"
​
    // transforming to a bytes4 value:
    meterify.utils.asciiToHex('yes', 4);
​
    // transforming to a bytes8 value:
    meterify.utils.asciiToHex('yes', 8);
​
    //etc.
Parameters:
string - String: A ASCII string to convert to a HEX string.
length - Number: The length of the returned hex string. The default size is 32 e.g.: bytes32.
Returns:
String: The HEX string.
hexToBytes    
meterify.utils.hexToBytes(hex)
Returns a byte array from the given HEX string.
Example:
    meterify.utils.hexToBytes('0x000000ea');
    > [ 0, 0, 0, 234 ]
​
    meterify.utils.hexToBytes(0x000000ea);
    > [ 234 ]
Parameters:
hex - String|HEX: A HEX to convert.
Returns:
Array: The byte array.
bytesToHex
meterify.utils.bytesToHex(byteArray)
Returns a HEX string from a byte array.
Example:
    meterify.utils.bytesToHex([ 72, 101, 108, 108, 111, 33, 36 ]);
    > "0x48656c6c6f2125"
Parameters:
byteArray - Array: A byte array to convert.
Returns:
String: The HEX string.
toWei    
meterify.utils.toWei(number [, unit])
Converts a Meter value into wei.
Example:
    meterify.utils.toWei('1', 'ether');
    > "1000000000000000000"
​
    meterify.utils.toWei('1', 'finney');
    > "1000000000000000"
​
    meterify.utils.toWei('1', 'szabo');
    > "1000000000000"
​
    meterify.utils.toWei('1', 'shannon');
    > "1000000000"
Note: wei are the smallest conversion unit, and you should always make calculations in wei and convert only for display reasons.
Parameters:
number - String|BN: The value.
unit - String (optional, defaults to "ether"): The ether to convert from. Possible units are:
noether: '0'
wei: '1'
kwei: '1000'
Kwei: '1000'
babbage: '1000'
femtoether: '1000'
mwei: '1000000'
Mwei: '1000000'
lovelace: '1000000'
picoether: '1000000'
gwei: '1000000000'
Gwei: '1000000000'
shannon: '1000000000'
nanoether: '1000000000'
nano: '1000000000'
szabo: '1000000000000'
microether: '1000000000000'
micro: '1000000000000'
finney: '1000000000000000'
milliether: '1000000000000000'
milli: '1000000000000000'
ether: '1000000000000000000'
kether: '1000000000000000000000'
grand: '1000000000000000000000'
mether: '1000000000000000000000000'
gether: '1000000000000000000000000000'
tether: '1000000000000000000000000000000'
Returns:
String|BN: If a string is given it returns a number string, otherwise a BN.js instance.
fromWei
    meterify.utils.fromWei(number [, unit])
Converts any wei value into another value.
Example:
​
    meterify.utils.fromWei('1', 'ether');
    > "0.000000000000000001"
​
    meterify.utils.fromWei('1', 'finney');
    > "0.000000000000001"
​
    meterify.utils.fromWei('1', 'szabo');
    > "0.000000000001"
​
    meterify.utils.fromWei('1', 'shannon');
    > "0.000000001"
Note: wei are the smallest conversion unit, and you should always make calculations in wei and convert only for display reasons.
Parameters:
number - String|BN: The value in wei.
unit - String (optional, defaults to "ether"): The ether to convert to. Possible units are:
noether: '0'
wei: '1'
kwei: '1000'
Kwei: '1000'
babbage: '1000'
femtoether: '1000'
mwei: '1000000'
Mwei: '1000000'
lovelace: '1000000'
picoether: '1000000'
gwei: '1000000000'
Gwei: '1000000000'
shannon: '1000000000'
nanoether: '1000000000'
nano: '1000000000'
szabo: '1000000000000'
microether: '1000000000000'
micro: '1000000000000'
finney: '1000000000000000'
milliether: '1000000000000000'
milli: '1000000000000000'
ether: '1000000000000000000'
kether: '1000000000000000000000'
grand: '1000000000000000000000'
mether: '1000000000000000000000000'
gether: '1000000000000000000000000000'
tether: '1000000000000000000000000000000'
Returns:
String: It always returns a string number.
unitMap
​
    meterify.utils.unitMap
Shows all possible values and their amount in wei.
Example:
​
    meterify.utils.unitMap
    > {
        noether: '0',
        wei:        '1',
        kwei:       '1000',
        Kwei:       '1000',
        babbage:    '1000',
        femtoether: '1000',
        mwei:       '1000000',
        Mwei:       '1000000',
        lovelace:   '1000000',
        picoether:  '1000000',
        gwei:       '1000000000',
        Gwei:       '1000000000',
        shannon:    '1000000000',
        nanoether:  '1000000000',
        nano:       '1000000000',
        szabo:      '1000000000000',
        microether: '1000000000000',
        micro:      '1000000000000',
        finney:     '1000000000000000',
        milliether: '1000000000000000',
        milli:      '1000000000000000',
        ether:      '1000000000000000000',
        kether:     '1000000000000000000000',
        grand:      '1000000000000000000000',
        mether:     '1000000000000000000000000',
        gether:     '1000000000000000000000000000',
        tether:     '1000000000000000000000000000000'
    }
Return value:
Object with the following properties:
noether: '0'
wei: '1'
kwei: '1000'
Kwei: '1000'
babbage: '1000'
femtoether: '1000'
mwei: '1000000'
Mwei: '1000000'
lovelace: '1000000'
picoether: '1000000'
gwei: '1000000000'
Gwei: '1000000000'
shannon: '1000000000'
nanoether: '1000000000'
nano: '1000000000'
szabo: '1000000000000'
microether: '1000000000000'
micro: '1000000000000'
finney: '1000000000000000'
milliether: '1000000000000000'
milli: '1000000000000000'
ether: '1000000000000000000'
kether: '1000000000000000000000'
grand: '1000000000000000000000'
mether: '1000000000000000000000000'
gether: '1000000000000000000000000000'
tether: '1000000000000000000000000000000'
padLeft
​
    meterify.utils.padLeft(string, characterAmount [, sign])
    meterify.utils.leftPad(string, characterAmount [, sign]) // ALIAS
Adds a padding on the left of a string. Useful for adding paddings to HEX strings.
Example:
​
    meterify.utils.padLeft('0x3456ff', 20);
    > "0x000000000000003456ff"
​
    meterify.utils.padLeft(0x3456ff, 20);
    > "0x000000000000003456ff"
​
    meterify.utils.padLeft('Hello', 20, 'x');
    > "xxxxxxxxxxxxxxxHello"
Parameters:
string - String: The string to add padding on the left.
characterAmount - Number: The number of characters the total string should have.
sign - String (optional): The character sign to use, defaults to "0".
Returns:
String: The padded string.
padRight
​
    meterify.utils.padRight(string, characterAmount [, sign])
    meterify.utils.rightPad(string, characterAmount [, sign]) // ALIAS
Adds a padding on the right of a string, Useful for adding paddings to HEX strings.
Example:
​
    meterify.utils.padRight('0x3456ff', 20);
    > "0x3456ff00000000000000"
​
    meterify.utils.padRight(0x3456ff, 20);
    > "0x3456ff00000000000000"
​
    meterify.utils.padRight('Hello', 20, 'x');
    > "Helloxxxxxxxxxxxxxxx"
Parameters:
string - String: The string to add padding on the right.
characterAmount - Number: The number of characters the total string should have.
sign - String (optional): The character sign to use, defaults to "0".
Returns:
String: The padded string.
toTwosComplement
​
    meterify.utils.toTwosComplement(number)
Converts a negative number into a two's complement.
Example:
​
    meterify.utils.toTwosComplement('-1');
    > "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
​
    meterify.utils.toTwosComplement(-1);
    > "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
​
    meterify.utils.toTwosComplement('0x1');
    > "0x0000000000000000000000000000000000000000000000000000000000000001"
​
    meterify.utils.toTwosComplement(-15);
    > "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff1"
​
    meterify.utils.toTwosComplement('-0x1');
    > "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
Parameters:
number - Number|String|BigNumber: The number to convert.
Returns:
String: The converted hex string.
getSignatureParameters
​
    meterify.utils.getSignatureParameters(string)
Gets the r, s and v values of an ECDSA signature
Example
​
    meterify.utils.getSignatureParameters('0x5763ab346198e3e6cc4d53996ccdeca0c941cb6cb70d671d97711c421d3bf7922c77ef244ad40e5262d1721bf9638fb06bab8ed3c43bfaa80d6da0be9bbd33dc1b');
    > "{ r: '0x5763ab346198e3e6cc4d53996ccdeca0c941cb6cb70d671d97711c421d3bf792', s: '0x2c77ef244ad40e5262d1721bf9638fb06bab8ed3c43bfaa80d6da0be9bbd33dc', v: 27 }"
Parameters:
string - String: An ECDSA signature.
Returns:
Object: Object containing r,s,v values.
meterify.eth.accounts
meterify.module.options
Last updated 6 months ago