allow specifying deadline in the router

src/router.ts

@@ -28,6 +28,14 @@ export interface TradeOptions {
   feeOnTransfer?: boolean
 }
 
+export interface TradeOptionsDeadline extends Omit<TradeOptions, 'ttl'> {
+  /**
+   * When the transaction expires.
+   * This is an atlernate to specifying the ttl, for when you do not want to use local time.
+   */
+  deadline: number
+}
+
 /**
  * The parameters to use in the call to the Uniswap V2 Router to execute a trade.
  */
@@ -65,18 +73,22 @@ export abstract class Router {
    * @param trade to produce call parameters for
    * @param options options for the call parameters
    */
-  public static swapCallParameters(trade: Trade, options: TradeOptions): SwapParameters {
+  public static swapCallParameters(trade: Trade, options: TradeOptions | TradeOptionsDeadline): SwapParameters {
     const etherIn = trade.inputAmount.currency === ETHER
     const etherOut = trade.outputAmount.currency === ETHER
     // the router does not support both ether in and out
     invariant(!(etherIn && etherOut), 'ETHER_IN_OUT')
-    invariant(options.ttl > 0, 'TTL')
+    invariant(!('ttl' in options) || options.ttl > 0, 'TTL')
 
     const to: string = validateAndParseAddress(options.recipient)
     const amountIn: string = toHex(trade.maximumAmountIn(options.allowedSlippage))
     const amountOut: string = toHex(trade.minimumAmountOut(options.allowedSlippage))
     const path: string[] = trade.route.path.map(token => token.address)
-    const deadline = `0x${(Math.floor(new Date().getTime() / 1000) + options.ttl).toString(16)}`
+    const deadline =
+      'ttl' in options
+        ? `0x${(Math.floor(new Date().getTime() / 1000) + options.ttl).toString(16)}`
+        : `0x${options.deadline.toString(16)}`
+
     const useFeeOnTransfer = Boolean(options.feeOnTransfer)
 
     let methodName: string

test/router.test.ts

@@ -33,6 +33,26 @@ describe('Router', () => {
         expect(result.value).toEqual('0x64')
         checkDeadline(result.args[result.args.length - 1])
       })
+
+      it('deadline specified', () => {
+        const result = Router.swapCallParameters(
+          Trade.exactIn(new Route([pair_weth_0, pair_0_1], ETHER, token1), CurrencyAmount.ether(JSBI.BigInt(100))),
+          {
+            deadline: 50,
+            recipient: '0x0000000000000000000000000000000000000004',
+            allowedSlippage: new Percent('1', '100')
+          }
+        )
+        expect(result.methodName).toEqual('swapExactETHForTokens')
+        expect(result.args).toEqual([
+          '0x51',
+          [WETH[ChainId.MAINNET].address, token0.address, token1.address],
+          '0x0000000000000000000000000000000000000004',
+          '0x32'
+        ])
+        expect(result.value).toEqual('0x64')
+      })
+
       it('token1 to ether', () => {
         const result = Router.swapCallParameters(
           Trade.exactIn(new Route([pair_0_1, pair_weth_0], token1, ETHER), new TokenAmount(token1, JSBI.BigInt(100))),