From fddad131a27d44bd923dab5a36f29baf0125fb8d Mon Sep 17 00:00:00 2001
From: Lawrence Forman <lawrence@0xproject.com>
Date: Fri, 26 Apr 2019 20:48:45 -0400
Subject: [PATCH] In `@0x/base-contract`: Expose `txHashPromise` in
 `PromiseWithTransactionHash`. In `@0x/abi-gen-templates`: Update
 `awaitTransactionSuccessAsync()` partial to expose `txHashPromise`.

---
 .../abi-gen-templates/partials/tx.handlebars  | 28 +++++++++++--------
 packages/base-contract/src/index.ts           | 12 ++++----
 2 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/packages/abi-gen-templates/partials/tx.handlebars b/packages/abi-gen-templates/partials/tx.handlebars
index a8c205ac93..0a834ca223 100644
--- a/packages/abi-gen-templates/partials/tx.handlebars
+++ b/packages/abi-gen-templates/partials/tx.handlebars
@@ -25,7 +25,7 @@ public {{this.tsName}} = {
         const txHash = await self._web3Wrapper.sendTransactionAsync(txDataWithDefaults);
         return txHash;
     },
-    async awaitTransactionSuccessAsync(
+    awaitTransactionSuccessAsync(
     {{> typed_params inputs=inputs}}
     {{#this.payable}}
         txData?: Partial<TxDataPayable> | number,
@@ -36,26 +36,30 @@ public {{this.tsName}} = {
         pollingIntervalMs?: number,
         timeoutMs?: number,
     ): PromiseWithTransactionHash<TransactionReceiptWithDecodedLogs> {
-        // `txData` is optional, so it might be set to `pollingIntervalMs`.
+        // `txData` may be omitted on its own, so it might be set to `pollingIntervalMs`.
         if (typeof(txData) === 'number') {
             pollingIntervalMs = txData;
             timeoutMs = pollingIntervalMs;
             txData = {};
         }
+        //
         const self = this as any as {{contractName}}Contract;
         {{#if inputs}}
-        const txHash = await self.{{this.tsName}}.sendTransactionAsync({{> params input=inputs}}, txData);
+        const txHashPromise = self.{{this.tsName}}.sendTransactionAsync({{> params input=inputs}}, txData);
         {{else}}
-        const txHash = await self.{{this.tsName}}.sendTransactionAsync(txData);
+        const txHashPromise = self.{{this.tsName}}.sendTransactionAsync(txData);
         {{/if}}
-        // tslint:disable-next-line: no-unnecessary-type-assertion
-        const receiptPromise = self._web3Wrapper.awaitTransactionSuccessAsync(
-            txHash,
-            pollingIntervalMs,
-            timeoutMs,
-        ) as any as PromiseWithTransactionHash<TransactionReceiptWithDecodedLogs>;
-        receiptPromise.txHash = txHash;
-        return receiptPromise;
+        return new PromiseWithTransactionHash<TransactionReceiptWithDecodedLogs>(
+            txHashPromise,
+            (async (): Promise<TransactionReceiptWithDecodedLogs> => {
+                // When the transaction hash resolves, wait for it to be mined.
+                return self._web3Wrapper.awaitTransactionSuccessAsync(
+                    await txHashPromise,
+                    pollingIntervalMs,
+                    timeoutMs,
+                );
+            })(),
+        );
     },
     async estimateGasAsync(
     {{> typed_params inputs=inputs}}
diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index ff6c7074a4..84a8e79313 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -26,14 +26,16 @@ export interface AbiEncoderByFunctionSignature {
  *      Not used by BaseContract, but generated contracts will return it in
  *      `awaitTransactionSuccessAsync()`.
  *      Maybe there's a better place for this.
- *      If you're wondering why this class is not simpler, it's to get around
- *      Typescript/ES5 transpiling issues.
  */
 export class PromiseWithTransactionHash<T> implements PromiseLike<T> {
-    public txHash: string = '';
+    public readonly txHashPromise: Promise<string>;
     private readonly _promise: Promise<T>;
-    constructor(handler: (resolve: (value?: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void) {
-        this._promise = new Promise(handler);
+    constructor(
+        txHashPromise: Promise<string>,
+        promise: Promise<T>,
+    ) {
+        this.txHashPromise = txHashPromise;
+        this._promise = promise;
     }
     public then<TResult>(
         onFulfilled?: (v: T) => TResult | PromiseLike<TResult>,