juggling some files around

contracts/test-utils/src/index.ts

@@ -15,7 +15,7 @@ export {
 export { getLatestBlockTimestampAsync, increaseTimeAndMineBlockAsync } from './block_timestamp';
 export { provider, txDefaults, web3Wrapper } from './web3_wrapper';
 export { LogDecoder } from './log_decoder';
-export { filterLogs, filterLogsToArguments } from './log_utils';
+export { filterLogs, filterLogsToArguments, verifyEvents } from './log_utils';
 export { signingUtils } from './signing_utils';
 export { orderUtils } from './order_utils';
 export { typeEncodingUtils } from './type_encoding_utils';

contracts/test-utils/src/log_utils.ts

@@ -1,4 +1,6 @@
-import { LogEntry, LogWithDecodedArgs } from 'ethereum-types';
+import { LogEntry, LogWithDecodedArgs, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+
+import { expect } from './chai_setup';
 
 // tslint:disable no-unnecessary-type-assertion
 
@@ -15,3 +17,18 @@ export function filterLogs<TEventArgs>(logs: LogEntry[], event: string): Array<L
 export function filterLogsToArguments<TEventArgs>(logs: LogEntry[], event: string): TEventArgs[] {
     return filterLogs<TEventArgs>(logs, event).map(log => log.args);
 }
+
+/**
+ * Verifies that a transaction emitted the expected events of a particular type.
+ */
+export function verifyEvents<TEventArgs>(
+    txReceipt: TransactionReceiptWithDecodedLogs,
+    expectedEvents: TEventArgs[],
+    eventName: string,
+): void {
+    const logs = filterLogsToArguments<TEventArgs>(txReceipt.logs, eventName);
+    expect(logs.length).to.eq(expectedEvents.length);
+    logs.forEach((log, index) => {
+        expect(log).to.deep.equal(expectedEvents[index]);
+    });
+}