Introduce SignedOrder class and remove type assertions

1 files changed, 92 insertions, 0 deletions

diff --git a/packages/contracts/util/signed_order.ts b/packages/contracts/util/signed_order.ts
new file mode 100644
index 000000000..a84e0686c
--- /dev/null
+++ b/packages/contracts/util/signed_order.ts
@@ -0,0 +1,92 @@
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import ethUtil = require('ethereumjs-util');
+import * as _ from 'lodash';
+
+import { crypto } from './crypto';
+import { SignedOrderParams } from './types';
+
+export class SignedOrder {
+    public params: SignedOrderParams;
+    private _web3Wrapper: Web3Wrapper;
+    constructor(web3Wrapper: Web3Wrapper, params: SignedOrderParams) {
+        this.params = params;
+        this._web3Wrapper = web3Wrapper;
+    }
+    public isValidSignature() {
+        const { v, r, s } = this.params;
+        const orderHash = this.getOrderHashHex();
+        const msgHash = ethUtil.hashPersonalMessage(ethUtil.toBuffer(orderHash));
+        try {
+            const pubKey = ethUtil.ecrecover(msgHash, v, ethUtil.toBuffer(r), ethUtil.toBuffer(s));
+            const recoveredAddress = ethUtil.bufferToHex(ethUtil.pubToAddress(pubKey));
+            return recoveredAddress === this.params.maker;
+        } catch (err) {
+            return false;
+        }
+    }
+    public createFill(shouldThrowOnInsufficientBalanceOrAllowance?: boolean, fillTakerTokenAmount?: BigNumber) {
+        const fill = {
+            orderAddresses: [
+                this.params.maker,
+                this.params.taker,
+                this.params.makerToken,
+                this.params.takerToken,
+                this.params.feeRecipient,
+            ],
+            orderValues: [
+                this.params.makerTokenAmount,
+                this.params.takerTokenAmount,
+                this.params.makerFee,
+                this.params.takerFee,
+                this.params.expirationTimestampInSec,
+                this.params.salt,
+            ],
+            fillTakerTokenAmount: fillTakerTokenAmount || this.params.takerTokenAmount,
+            shouldThrowOnInsufficientBalanceOrAllowance: !!shouldThrowOnInsufficientBalanceOrAllowance,
+            v: this.params.v,
+            r: this.params.r,
+            s: this.params.s,
+        };
+        return fill;
+    }
+    public createCancel(cancelTakerTokenAmount?: BigNumber) {
+        const cancel = {
+            orderAddresses: [
+                this.params.maker,
+                this.params.taker,
+                this.params.makerToken,
+                this.params.takerToken,
+                this.params.feeRecipient,
+            ],
+            orderValues: [
+                this.params.makerTokenAmount,
+                this.params.takerTokenAmount,
+                this.params.makerFee,
+                this.params.takerFee,
+                this.params.expirationTimestampInSec,
+                this.params.salt,
+            ],
+            cancelTakerTokenAmount: cancelTakerTokenAmount || this.params.takerTokenAmount,
+        };
+        return cancel;
+    }
+    public getOrderHashHex(): string {
+        const orderHash = crypto.solSHA3([
+            this.params.exchangeContractAddress,
+            this.params.maker,
+            this.params.taker,
+            this.params.makerToken,
+            this.params.takerToken,
+            this.params.feeRecipient,
+            this.params.makerTokenAmount,
+            this.params.takerTokenAmount,
+            this.params.makerFee,
+            this.params.takerFee,
+            this.params.expirationTimestampInSec,
+            this.params.salt,
+        ]);
+        const orderHashHex = ethUtil.bufferToHex(orderHash);
+        return orderHashHex;
+    }
+}