Add api.util.encodeMethodCall to parity.js (#4330)

* Add api.util.encodeMethodCall

* Update spec description path, strip hex

* Remove options, add encodeMethodCall(name, inputs) signature

* Simplify interface with types-only inputs

* Add abiEncode & abiDecode functions

js/src/api/util/decode.js

@@ -85,3 +85,11 @@ export function methodToAbi (method) {
 
   return { type: 'function', name, inputs };
 }
+
+export function abiDecode (inputTypes, data) {
+  return decodeMethodInput({
+    inputs: inputTypes.map((type) => {
+      return { type };
+    })
+  }, data);
+}

js/src/api/util/decode.spec.js

@@ -15,7 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 import BigNumber from 'bignumber.js';
-import { decodeCallData, decodeMethodInput, methodToAbi } from './decode';
+import { abiDecode, decodeCallData, decodeMethodInput, methodToAbi } from './decode';
 
 describe('api/util/decode', () => {
   const METH = '0x70a08231';
@@ -49,12 +49,16 @@ describe('api/util/decode', () => {
     });
 
     it('correctly decodes valid inputs', () => {
-      expect(decodeMethodInput({
-        type: 'function',
-        inputs: [
-          { type: 'uint' }
-        ]
-      }, DATA)).to.deep.equal([ new BigNumber('0x5a5eff38da95b0d58b6c616f2699168b480953c9') ]);
+      expect(
+        decodeMethodInput({
+          type: 'function',
+          inputs: [
+            { type: 'uint' }
+          ]
+        }, DATA)
+      ).to.deep.equal(
+        [ new BigNumber('0x5a5eff38da95b0d58b6c616f2699168b480953c9') ]
+      );
     });
   });
 
@@ -90,4 +94,12 @@ describe('api/util/decode', () => {
       });
     });
   });
+
+  describe('abiDecode', () => {
+    it('correctly decodes valid inputs', () => {
+      expect(abiDecode(['uint'], DATA)).to.deep.equal(
+        [ new BigNumber('0x5a5eff38da95b0d58b6c616f2699168b480953c9') ]
+      );
+    });
+  });
 });

js/src/api/util/encode.js

@@ -0,0 +1,40 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import Abi from '~/abi';
+import Func from '~/abi/spec/function';
+
+export function encodeMethodCallAbi (methodAbi = {}, values = []) {
+  const func = new Func(methodAbi);
+  const tokens = Abi.encodeTokens(func.inputParamTypes(), values);
+  const call = func.encodeCall(tokens);
+
+  return `0x${call}`;
+}
+
+export function abiEncode (methodName, inputTypes, data) {
+  const result = encodeMethodCallAbi({
+    name: methodName || '',
+    type: 'function',
+    inputs: inputTypes.map((type) => {
+      return { type };
+    })
+  }, data);
+
+  return methodName === null
+    ? `0x${result.substr(10)}`
+    : result;
+}

js/src/api/util/encode.spec.js

@@ -0,0 +1,63 @@
+// Copyright 2015-2017 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import { abiEncode, encodeMethodCallAbi } from './encode';
+
+const ABI = {
+  type: 'function',
+  name: 'valid',
+  inputs: [
+    { type: 'uint256' },
+    { type: 'bool' }
+  ]
+};
+
+const RESULT = [
+  'f87fa141',
+  '0000000000000000000000000000000000000000000000000000000000000123',
+  '0000000000000000000000000000000000000000000000000000000000000001'
+].join('');
+const VARIABLE = [
+  '5a6fbce0',
+  'c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470',
+  '0000000000000000000000000000000000000000000000000000000000000040',
+  '000000000000000000000000000000000000000000000000000000000000000f',
+  '687474703a2f2f666f6f2e6261722f0000000000000000000000000000000000'
+].join('');
+
+describe('api/util/encode', () => {
+  describe('encodeMethodCallAbi', () => {
+    it('encodes calls with the correct result', () => {
+      expect(encodeMethodCallAbi(ABI, [0x123, true])).to.equal(`0x${RESULT}`);
+    });
+  });
+
+  describe('abiEncode', () => {
+    it('encodes calls with the correct result', () => {
+      expect(abiEncode('valid', ['uint256', 'bool'], [0x123, true])).to.equal(`0x${RESULT}`);
+    });
+
+    it('encodes variable values', () => {
+      expect(abiEncode('hintUrl', ['bytes32', 'string'], ['0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470', 'http://foo.bar/'])).to.equal(`0x${VARIABLE}`);
+    });
+
+    it('encodes only the data with null name', () => {
+      expect(
+        abiEncode(null, ['uint256', 'bool'], [0x123, true])
+      ).to.equal(`0x${RESULT.substr(8)}`);
+    });
+  });
+});

js/src/api/util/index.js

@@ -15,7 +15,8 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 import { isAddress as isAddressValid, toChecksumAddress } from '../../abi/util/address';
-import { decodeCallData, decodeMethodInput, methodToAbi } from './decode';
+import { abiDecode, decodeCallData, decodeMethodInput, methodToAbi } from './decode';
+import { abiEncode, encodeMethodCallAbi } from './encode';
 import { bytesToHex, hexToAscii, asciiToHex } from './format';
 import { fromWei, toWei } from './wei';
 import { sha3 } from './sha3';
@@ -23,6 +24,8 @@ import { isArray, isFunction, isHex, isInstanceOf, isString } from './types';
 import { createIdentityImg } from './identity';
 
 export default {
+  abiDecode,
+  abiEncode,
   isAddressValid,
   isArray,
   isFunction,
@@ -35,6 +38,7 @@ export default {
   createIdentityImg,
   decodeCallData,
   decodeMethodInput,
+  encodeMethodCallAbi,
   methodToAbi,
   fromWei,
   toChecksumAddress,