add toSolidityBytes32

lib/index.js

@@ -424,6 +424,52 @@ ABI.stringify = function (types, values) {
   return ret
 }
 
+ABI.toSolidityBytes32 = function(type, value) {
+    type = elementaryName(type);
+    var ret = []
+    if (type === 'bytes') {
+      ret.push(utils.setLengthRight(value, 32))
+    } else if (type === 'bool') {
+      ret.push(utils.setLengthLeft(value ? 1 : 0, 32));
+    } else if (type === 'address') {
+      ret.push(utils.setLengthLeft(value, 32))
+    } else if (type.startsWith('bytes')) {
+      size = parseTypeN(type)
+      if (size < 1 || size > 32) {
+        throw new Error('Invalid bytes<N> width: ' + size)
+      }
+      ret.push(utils.setLengthRight(value, 32))
+    } else if (type.startsWith('uint')) {
+      size = parseTypeN(type)
+      if ((size % 8) || (size < 8) || (size > 256)) {
+        throw new Error('Invalid uint<N> width: ' + size)
+      }
+
+      num = parseNumber(value)
+      if (num.bitLength() > size) {
+        throw new Error('Supplied uint exceeds width: ' + size + ' vs ' + num.bitLength())
+      }
+
+      ret.push(num.toArrayLike(Buffer, 'be', 32))
+    } else if (type.startsWith('int')) {
+      size = parseTypeN(type)
+      if ((size % 8) || (size < 8) || (size > 256)) {
+        throw new Error('Invalid int<N> width: ' + size)
+      }
+
+      num = parseNumber(value)
+      if (num.bitLength() > size) {
+        throw new Error('Supplied int exceeds width: ' + size + ' vs ' + num.bitLength())
+      }
+
+      ret.push(num.toTwos(size).toArrayLike(Buffer, 'be', 32))
+    } else {
+      // FIXME: support all other types : like string
+      throw new Error('Unsupported or invalid type: ' + type)
+    }
+    return ret;
+}
+
 ABI.solidityPack = function (types, values) {
   if (types.length !== values.length) {
     throw new Error('Number of types are not matching the values')