1 files changed, 55 insertions, 0 deletions
diff --git a/packages/contracts/test/utils/log_decoder.ts b/packages/contracts/test/utils/log_decoder.ts
new file mode 100644
index 000000000..07127ba79
--- /dev/null
+++ b/packages/contracts/test/utils/log_decoder.ts
@@ -0,0 +1,55 @@
+import { ContractArtifact } from '@0xproject/sol-compiler';
+import { AbiDecoder, BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import {
+    AbiDefinition,
+    DecodedLogArgs,
+    LogEntry,
+    LogWithDecodedArgs,
+    RawLog,
+    TransactionReceiptWithDecodedLogs,
+} from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { artifacts } from './artifacts';
+import { constants } from './constants';
+
+export class LogDecoder {
+    private _web3Wrapper: Web3Wrapper;
+    private _contractAddress: string;
+    private _abiDecoder: AbiDecoder;
+    public static wrapLogBigNumbers(log: any): any {
+        const argNames = _.keys(log.args);
+        for (const argName of argNames) {
+            const isWeb3BigNumber = _.startsWith(log.args[argName].constructor.toString(), 'function BigNumber(');
+            if (isWeb3BigNumber) {
+                log.args[argName] = new BigNumber(log.args[argName]);
+            }
+        }
+    }
+    constructor(web3Wrapper: Web3Wrapper, contractAddress: string) {
+        this._web3Wrapper = web3Wrapper;
+        this._contractAddress = contractAddress;
+        const abiArrays: AbiDefinition[][] = [];
+        _.forEach(artifacts, (artifact: ContractArtifact) => {
+            const compilerOutput = artifact.compilerOutput;
+            abiArrays.push(compilerOutput.abi);
+        });
+        this._abiDecoder = new AbiDecoder(abiArrays);
+    }
+    public decodeLogOrThrow<ArgsType extends DecodedLogArgs>(log: LogEntry): LogWithDecodedArgs<ArgsType> | RawLog {
+        const logWithDecodedArgsOrLog = this._abiDecoder.tryToDecodeLogOrNoop(log);
+        // tslint:disable-next-line:no-unnecessary-type-assertion
+        if (_.isUndefined((logWithDecodedArgsOrLog as LogWithDecodedArgs<ArgsType>).args)) {
+            throw new Error(`Unable to decode log: ${JSON.stringify(log)}`);
+        }
+        LogDecoder.wrapLogBigNumbers(logWithDecodedArgsOrLog);
+        return logWithDecodedArgsOrLog;
+    }
+    public async getTxWithDecodedLogsAsync(txHash: string): Promise<TransactionReceiptWithDecodedLogs> {
+        const tx = await this._web3Wrapper.awaitTransactionSuccessAsync(txHash, constants.AWAIT_TRANSACTION_MINED_MS);
+        tx.logs = _.filter(tx.logs, log => log.address === this._contractAddress);
+        tx.logs = _.map(tx.logs, log => this.decodeLogOrThrow(log));
+        return tx;
+    }
+}