Merge branch 'development' into feature/addSubproviders

* development: (50 commits)
  Add PR number to changelog
  Address feedback
  Add requestId to subscription messages and update json-schemas
  Remove isomorphic-fetch types from contracts package
  Update README
  Regenerate files
  Make it private
  Change package name
  Update README
  Make fileExtension configurable
  Rename abi-gen to typed-contracts
  Add docs for typed-contracts
  Remove TODOs
  Introduce separate ContextData type and rework it
  Check ABI is defined
  Introduce a const for 'contract.mustache'
  Improve error message
  Reuse util
  Fix a typo
  Introduce a const for 'function'
  ...

# Conflicts:
#	yarn.lock

1 files changed, 38 insertions, 0 deletions

diff --git a/packages/contracts/util/crypto.ts b/packages/contracts/util/crypto.ts
new file mode 100644
index 000000000..5253b8c15
--- /dev/null
+++ b/packages/contracts/util/crypto.ts
@@ -0,0 +1,38 @@
+import {BigNumber} from 'bignumber.js';
+import BN = require('bn.js');
+import ABI = require('ethereumjs-abi');
+import ethUtil = require('ethereumjs-util');
+import * as _ from 'lodash';
+
+export const crypto = {
+    /*
+   * We convert types from JS to Solidity as follows:
+   * BigNumber -> uint256
+   * number -> uint8
+   * string -> string
+   * boolean -> bool
+   * valid Ethereum address -> address
+   */
+    solSHA3(args: any[]): Buffer {
+        const argTypes: string[] = [];
+        _.each(args, (arg, i) => {
+            const isNumber = _.isFinite(arg);
+            if (isNumber) {
+                argTypes.push('uint8');
+            } else if ((arg).isBigNumber) {
+                argTypes.push('uint256');
+                args[i] = new BN(arg.toString(10), 10);
+            } else if (ethUtil.isValidAddress(arg)) {
+                argTypes.push('address');
+            } else if (_.isString(arg)) {
+                argTypes.push('string');
+            } else if  (_.isBoolean(arg)) {
+                argTypes.push('bool');
+            } else {
+                throw new Error(`Unable to guess arg type: ${arg}`);
+            }
+        });
+        const hash = ABI.soliditySHA3(argTypes, args);
+        return hash;
+    },
+};