Merge branch 'development' into feature/sra-reporter

* development: (71 commits)
  Set max to 2 ETH/2 ZRX
  Add missing types from website
  Add dependencies
  Update the README
  Move BaseContract to its own package
  Upgrate prettier
  remove unused import
  Move more configs into docsInfo and remove logic that does not belong there elsewhere
  Fix a bug with displaying solidity functions returning multiple return values
  Add ethers-contracts as a dependency
  Include types for ethers-contracts
  Fix the version
  Include types for ethers-contracts
  Rename idx to i
  Remove tslint disable
  Move BaseContract to web3Wrapper
  Merge ifs
  Fix an option description
  Add link to the docs
  Improve CHANGELOG entry
  ...

1 files changed, 68 insertions, 0 deletions

diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
new file mode 100644
index 000000000..cc1e16a13
--- /dev/null
+++ b/packages/base-contract/src/index.ts
@@ -0,0 +1,68 @@
+import { TxData, TxDataPayable } from '@0xproject/types';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import * as ethersContracts from 'ethers-contracts';
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+export class BaseContract {
+    protected _ethersInterface: ethersContracts.Interface;
+    protected _web3Wrapper: Web3Wrapper;
+    public abi: Web3.ContractAbi;
+    public address: string;
+    protected static _transformABIData(
+        abis: Web3.DataItem[],
+        values: any[],
+        transformation: (type: string, value: any) => any,
+    ): any {
+        return _.map(values, (value: any, i: number) =>
+            BaseContract._transformTypedData(abis[i].type, value, transformation),
+        );
+    }
+    protected static _lowercaseAddress(type: string, value: string): string {
+        return type === 'address' ? value.toLowerCase() : value;
+    }
+    protected static _bigNumberToString(type: string, value: string): string {
+        return _.isObject(value) && (value as any).isBigNumber ? value.toString() : value;
+    }
+    private static _transformTypedData(
+        type: string,
+        values: any,
+        transformation: (type: string, value: any) => any,
+    ): any {
+        const trailingArrayRegex = /\[\d*\]$/;
+        if (type.match(trailingArrayRegex)) {
+            const arrayItemType = type.replace(trailingArrayRegex, '');
+            return _.map(values, value => this._transformTypedData(arrayItemType, value, transformation));
+        } else {
+            return transformation(type, values);
+        }
+    }
+    protected async _applyDefaultsToTxDataAsync<T extends Partial<TxData | TxDataPayable>>(
+        txData: T,
+        estimateGasAsync?: (txData: T) => Promise<number>,
+    ): Promise<TxData> {
+        // Gas amount sourced with the following priorities:
+        // 1. Optional param passed in to public method call
+        // 2. Global config passed in at library instantiation
+        // 3. Gas estimate calculation + safety margin
+        const removeUndefinedProperties = _.pickBy;
+        const txDataWithDefaults = {
+            to: this.address,
+            ...removeUndefinedProperties(this._web3Wrapper.getContractDefaults()),
+            ...removeUndefinedProperties(txData as any),
+            // HACK: TS can't prove that T is spreadable.
+            // Awaiting https://github.com/Microsoft/TypeScript/pull/13288 to be merged
+        };
+        if (_.isUndefined(txDataWithDefaults.gas) && !_.isUndefined(estimateGasAsync)) {
+            const estimatedGas = await estimateGasAsync(txData);
+            txDataWithDefaults.gas = estimatedGas;
+        }
+        return txDataWithDefaults;
+    }
+    constructor(web3Wrapper: Web3Wrapper, abi: Web3.ContractAbi, address: string) {
+        this._web3Wrapper = web3Wrapper;
+        this.abi = abi;
+        this.address = address;
+        this._ethersInterface = new ethersContracts.Interface(abi);
+    }
+}