Refactor event scraping and add support for scraping ERC20 approval events (#1401)

* Refactor event scraping and add support for scraping ERC20 approval events

* Add tests for data_sources/contract-wrappers/utils

3 files changed, 169 insertions, 133 deletions

diff --git a/packages/pipeline/src/parsers/events/erc20_events.ts b/packages/pipeline/src/parsers/events/erc20_events.ts
new file mode 100644
index 000000000..caf9984d0
--- /dev/null
+++ b/packages/pipeline/src/parsers/events/erc20_events.ts
@@ -0,0 +1,34 @@
+import { ERC20TokenApprovalEventArgs } from '@0x/contract-wrappers';
+import { LogWithDecodedArgs } from 'ethereum-types';
+import * as R from 'ramda';
+
+import { ERC20ApprovalEvent } from '../../entities';
+
+/**
+ * Parses raw event logs for an ERC20 approval event and returns an array of
+ * ERC20ApprovalEvent entities.
+ * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
+ */
+export const parseERC20ApprovalEvents: (
+    eventLogs: Array<LogWithDecodedArgs<ERC20TokenApprovalEventArgs>>,
+) => ERC20ApprovalEvent[] = R.map(_convertToERC20ApprovalEvent);
+
+/**
+ * Converts a raw event log for an ERC20 approval event into an
+ * ERC20ApprovalEvent entity.
+ * @param eventLog Raw event log (e.g. returned from contract-wrappers).
+ */
+export function _convertToERC20ApprovalEvent(
+    eventLog: LogWithDecodedArgs<ERC20TokenApprovalEventArgs>,
+): ERC20ApprovalEvent {
+    const erc20ApprovalEvent = new ERC20ApprovalEvent();
+    erc20ApprovalEvent.tokenAddress = eventLog.address as string;
+    erc20ApprovalEvent.blockNumber = eventLog.blockNumber as number;
+    erc20ApprovalEvent.logIndex = eventLog.logIndex as number;
+    erc20ApprovalEvent.rawData = eventLog.data as string;
+    erc20ApprovalEvent.transactionHash = eventLog.transactionHash;
+    erc20ApprovalEvent.ownerAddress = eventLog.args._owner;
+    erc20ApprovalEvent.spenderAddress = eventLog.args._spender;
+    erc20ApprovalEvent.amount = eventLog.args._value;
+    return erc20ApprovalEvent;
+}
diff --git a/packages/pipeline/src/parsers/events/exchange_events.ts b/packages/pipeline/src/parsers/events/exchange_events.ts
new file mode 100644
index 000000000..e18106c75
--- /dev/null
+++ b/packages/pipeline/src/parsers/events/exchange_events.ts
@@ -0,0 +1,133 @@
+import { ExchangeCancelEventArgs, ExchangeCancelUpToEventArgs, ExchangeFillEventArgs } from '@0x/contract-wrappers';
+import { assetDataUtils } from '@0x/order-utils';
+import { AssetProxyId, ERC721AssetData } from '@0x/types';
+import { LogWithDecodedArgs } from 'ethereum-types';
+import * as R from 'ramda';
+
+import { ExchangeCancelEvent, ExchangeCancelUpToEvent, ExchangeFillEvent } from '../../entities';
+import { bigNumbertoStringOrNull } from '../../utils';
+
+/**
+ * Parses raw event logs for a fill event and returns an array of
+ * ExchangeFillEvent entities.
+ * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
+ */
+export const parseExchangeFillEvents: (
+    eventLogs: Array<LogWithDecodedArgs<ExchangeFillEventArgs>>,
+) => ExchangeFillEvent[] = R.map(_convertToExchangeFillEvent);
+
+/**
+ * Parses raw event logs for a cancel event and returns an array of
+ * ExchangeCancelEvent entities.
+ * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
+ */
+export const parseExchangeCancelEvents: (
+    eventLogs: Array<LogWithDecodedArgs<ExchangeCancelEventArgs>>,
+) => ExchangeCancelEvent[] = R.map(_convertToExchangeCancelEvent);
+
+/**
+ * Parses raw event logs for a CancelUpTo event and returns an array of
+ * ExchangeCancelUpToEvent entities.
+ * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
+ */
+export const parseExchangeCancelUpToEvents: (
+    eventLogs: Array<LogWithDecodedArgs<ExchangeCancelUpToEventArgs>>,
+) => ExchangeCancelUpToEvent[] = R.map(_convertToExchangeCancelUpToEvent);
+
+/**
+ * Converts a raw event log for a fill event into an ExchangeFillEvent entity.
+ * @param eventLog Raw event log (e.g. returned from contract-wrappers).
+ */
+export function _convertToExchangeFillEvent(eventLog: LogWithDecodedArgs<ExchangeFillEventArgs>): ExchangeFillEvent {
+    const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
+    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
+    const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
+    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
+    const exchangeFillEvent = new ExchangeFillEvent();
+    exchangeFillEvent.contractAddress = eventLog.address as string;
+    exchangeFillEvent.blockNumber = eventLog.blockNumber as number;
+    exchangeFillEvent.logIndex = eventLog.logIndex as number;
+    exchangeFillEvent.rawData = eventLog.data as string;
+    exchangeFillEvent.transactionHash = eventLog.transactionHash;
+    exchangeFillEvent.makerAddress = eventLog.args.makerAddress;
+    exchangeFillEvent.takerAddress = eventLog.args.takerAddress;
+    exchangeFillEvent.feeRecipientAddress = eventLog.args.feeRecipientAddress;
+    exchangeFillEvent.senderAddress = eventLog.args.senderAddress;
+    exchangeFillEvent.makerAssetFilledAmount = eventLog.args.makerAssetFilledAmount;
+    exchangeFillEvent.takerAssetFilledAmount = eventLog.args.takerAssetFilledAmount;
+    exchangeFillEvent.makerFeePaid = eventLog.args.makerFeePaid;
+    exchangeFillEvent.takerFeePaid = eventLog.args.takerFeePaid;
+    exchangeFillEvent.orderHash = eventLog.args.orderHash;
+    exchangeFillEvent.rawMakerAssetData = eventLog.args.makerAssetData;
+    exchangeFillEvent.makerAssetType = makerAssetType;
+    exchangeFillEvent.makerAssetProxyId = makerAssetData.assetProxyId;
+    exchangeFillEvent.makerTokenAddress = makerAssetData.tokenAddress;
+    // tslint has a false positive here. Type assertion is required.
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeFillEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
+    exchangeFillEvent.rawTakerAssetData = eventLog.args.takerAssetData;
+    exchangeFillEvent.takerAssetType = takerAssetType;
+    exchangeFillEvent.takerAssetProxyId = takerAssetData.assetProxyId;
+    exchangeFillEvent.takerTokenAddress = takerAssetData.tokenAddress;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeFillEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
+    return exchangeFillEvent;
+}
+
+/**
+ * Converts a raw event log for a cancel event into an ExchangeCancelEvent
+ * entity.
+ * @param eventLog Raw event log (e.g. returned from contract-wrappers).
+ */
+export function _convertToExchangeCancelEvent(
+    eventLog: LogWithDecodedArgs<ExchangeCancelEventArgs>,
+): ExchangeCancelEvent {
+    const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
+    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
+    const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
+    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
+    const exchangeCancelEvent = new ExchangeCancelEvent();
+    exchangeCancelEvent.contractAddress = eventLog.address as string;
+    exchangeCancelEvent.blockNumber = eventLog.blockNumber as number;
+    exchangeCancelEvent.logIndex = eventLog.logIndex as number;
+    exchangeCancelEvent.rawData = eventLog.data as string;
+    exchangeCancelEvent.transactionHash = eventLog.transactionHash;
+    exchangeCancelEvent.makerAddress = eventLog.args.makerAddress;
+    exchangeCancelEvent.takerAddress = eventLog.args.takerAddress;
+    exchangeCancelEvent.feeRecipientAddress = eventLog.args.feeRecipientAddress;
+    exchangeCancelEvent.senderAddress = eventLog.args.senderAddress;
+    exchangeCancelEvent.orderHash = eventLog.args.orderHash;
+    exchangeCancelEvent.rawMakerAssetData = eventLog.args.makerAssetData;
+    exchangeCancelEvent.makerAssetType = makerAssetType;
+    exchangeCancelEvent.makerAssetProxyId = makerAssetData.assetProxyId;
+    exchangeCancelEvent.makerTokenAddress = makerAssetData.tokenAddress;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeCancelEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
+    exchangeCancelEvent.rawTakerAssetData = eventLog.args.takerAssetData;
+    exchangeCancelEvent.takerAssetType = takerAssetType;
+    exchangeCancelEvent.takerAssetProxyId = takerAssetData.assetProxyId;
+    exchangeCancelEvent.takerTokenAddress = takerAssetData.tokenAddress;
+    // tslint:disable-next-line:no-unnecessary-type-assertion
+    exchangeCancelEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
+    return exchangeCancelEvent;
+}
+
+/**
+ * Converts a raw event log for a cancelUpTo event into an
+ * ExchangeCancelUpToEvent entity.
+ * @param eventLog Raw event log (e.g. returned from contract-wrappers).
+ */
+export function _convertToExchangeCancelUpToEvent(
+    eventLog: LogWithDecodedArgs<ExchangeCancelUpToEventArgs>,
+): ExchangeCancelUpToEvent {
+    const exchangeCancelUpToEvent = new ExchangeCancelUpToEvent();
+    exchangeCancelUpToEvent.contractAddress = eventLog.address as string;
+    exchangeCancelUpToEvent.blockNumber = eventLog.blockNumber as number;
+    exchangeCancelUpToEvent.logIndex = eventLog.logIndex as number;
+    exchangeCancelUpToEvent.rawData = eventLog.data as string;
+    exchangeCancelUpToEvent.transactionHash = eventLog.transactionHash;
+    exchangeCancelUpToEvent.makerAddress = eventLog.args.makerAddress;
+    exchangeCancelUpToEvent.senderAddress = eventLog.args.senderAddress;
+    exchangeCancelUpToEvent.orderEpoch = eventLog.args.orderEpoch;
+    return exchangeCancelUpToEvent;
+}
diff --git a/packages/pipeline/src/parsers/events/index.ts b/packages/pipeline/src/parsers/events/index.ts
index e18106c75..3f9915e8b 100644
--- a/packages/pipeline/src/parsers/events/index.ts
+++ b/packages/pipeline/src/parsers/events/index.ts
@@ -1,133 +1,2 @@
-import { ExchangeCancelEventArgs, ExchangeCancelUpToEventArgs, ExchangeFillEventArgs } from '@0x/contract-wrappers';
-import { assetDataUtils } from '@0x/order-utils';
-import { AssetProxyId, ERC721AssetData } from '@0x/types';
-import { LogWithDecodedArgs } from 'ethereum-types';
-import * as R from 'ramda';
-
-import { ExchangeCancelEvent, ExchangeCancelUpToEvent, ExchangeFillEvent } from '../../entities';
-import { bigNumbertoStringOrNull } from '../../utils';
-
-/**
- * Parses raw event logs for a fill event and returns an array of
- * ExchangeFillEvent entities.
- * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
- */
-export const parseExchangeFillEvents: (
-    eventLogs: Array<LogWithDecodedArgs<ExchangeFillEventArgs>>,
-) => ExchangeFillEvent[] = R.map(_convertToExchangeFillEvent);
-
-/**
- * Parses raw event logs for a cancel event and returns an array of
- * ExchangeCancelEvent entities.
- * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
- */
-export const parseExchangeCancelEvents: (
-    eventLogs: Array<LogWithDecodedArgs<ExchangeCancelEventArgs>>,
-) => ExchangeCancelEvent[] = R.map(_convertToExchangeCancelEvent);
-
-/**
- * Parses raw event logs for a CancelUpTo event and returns an array of
- * ExchangeCancelUpToEvent entities.
- * @param eventLogs Raw event logs (e.g. returned from contract-wrappers).
- */
-export const parseExchangeCancelUpToEvents: (
-    eventLogs: Array<LogWithDecodedArgs<ExchangeCancelUpToEventArgs>>,
-) => ExchangeCancelUpToEvent[] = R.map(_convertToExchangeCancelUpToEvent);
-
-/**
- * Converts a raw event log for a fill event into an ExchangeFillEvent entity.
- * @param eventLog Raw event log (e.g. returned from contract-wrappers).
- */
-export function _convertToExchangeFillEvent(eventLog: LogWithDecodedArgs<ExchangeFillEventArgs>): ExchangeFillEvent {
-    const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
-    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
-    const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
-    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
-    const exchangeFillEvent = new ExchangeFillEvent();
-    exchangeFillEvent.contractAddress = eventLog.address as string;
-    exchangeFillEvent.blockNumber = eventLog.blockNumber as number;
-    exchangeFillEvent.logIndex = eventLog.logIndex as number;
-    exchangeFillEvent.rawData = eventLog.data as string;
-    exchangeFillEvent.transactionHash = eventLog.transactionHash;
-    exchangeFillEvent.makerAddress = eventLog.args.makerAddress;
-    exchangeFillEvent.takerAddress = eventLog.args.takerAddress;
-    exchangeFillEvent.feeRecipientAddress = eventLog.args.feeRecipientAddress;
-    exchangeFillEvent.senderAddress = eventLog.args.senderAddress;
-    exchangeFillEvent.makerAssetFilledAmount = eventLog.args.makerAssetFilledAmount;
-    exchangeFillEvent.takerAssetFilledAmount = eventLog.args.takerAssetFilledAmount;
-    exchangeFillEvent.makerFeePaid = eventLog.args.makerFeePaid;
-    exchangeFillEvent.takerFeePaid = eventLog.args.takerFeePaid;
-    exchangeFillEvent.orderHash = eventLog.args.orderHash;
-    exchangeFillEvent.rawMakerAssetData = eventLog.args.makerAssetData;
-    exchangeFillEvent.makerAssetType = makerAssetType;
-    exchangeFillEvent.makerAssetProxyId = makerAssetData.assetProxyId;
-    exchangeFillEvent.makerTokenAddress = makerAssetData.tokenAddress;
-    // tslint has a false positive here. Type assertion is required.
-    // tslint:disable-next-line:no-unnecessary-type-assertion
-    exchangeFillEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
-    exchangeFillEvent.rawTakerAssetData = eventLog.args.takerAssetData;
-    exchangeFillEvent.takerAssetType = takerAssetType;
-    exchangeFillEvent.takerAssetProxyId = takerAssetData.assetProxyId;
-    exchangeFillEvent.takerTokenAddress = takerAssetData.tokenAddress;
-    // tslint:disable-next-line:no-unnecessary-type-assertion
-    exchangeFillEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
-    return exchangeFillEvent;
-}
-
-/**
- * Converts a raw event log for a cancel event into an ExchangeCancelEvent
- * entity.
- * @param eventLog Raw event log (e.g. returned from contract-wrappers).
- */
-export function _convertToExchangeCancelEvent(
-    eventLog: LogWithDecodedArgs<ExchangeCancelEventArgs>,
-): ExchangeCancelEvent {
-    const makerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.makerAssetData);
-    const makerAssetType = makerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
-    const takerAssetData = assetDataUtils.decodeAssetDataOrThrow(eventLog.args.takerAssetData);
-    const takerAssetType = takerAssetData.assetProxyId === AssetProxyId.ERC20 ? 'erc20' : 'erc721';
-    const exchangeCancelEvent = new ExchangeCancelEvent();
-    exchangeCancelEvent.contractAddress = eventLog.address as string;
-    exchangeCancelEvent.blockNumber = eventLog.blockNumber as number;
-    exchangeCancelEvent.logIndex = eventLog.logIndex as number;
-    exchangeCancelEvent.rawData = eventLog.data as string;
-    exchangeCancelEvent.transactionHash = eventLog.transactionHash;
-    exchangeCancelEvent.makerAddress = eventLog.args.makerAddress;
-    exchangeCancelEvent.takerAddress = eventLog.args.takerAddress;
-    exchangeCancelEvent.feeRecipientAddress = eventLog.args.feeRecipientAddress;
-    exchangeCancelEvent.senderAddress = eventLog.args.senderAddress;
-    exchangeCancelEvent.orderHash = eventLog.args.orderHash;
-    exchangeCancelEvent.rawMakerAssetData = eventLog.args.makerAssetData;
-    exchangeCancelEvent.makerAssetType = makerAssetType;
-    exchangeCancelEvent.makerAssetProxyId = makerAssetData.assetProxyId;
-    exchangeCancelEvent.makerTokenAddress = makerAssetData.tokenAddress;
-    // tslint:disable-next-line:no-unnecessary-type-assertion
-    exchangeCancelEvent.makerTokenId = bigNumbertoStringOrNull((makerAssetData as ERC721AssetData).tokenId);
-    exchangeCancelEvent.rawTakerAssetData = eventLog.args.takerAssetData;
-    exchangeCancelEvent.takerAssetType = takerAssetType;
-    exchangeCancelEvent.takerAssetProxyId = takerAssetData.assetProxyId;
-    exchangeCancelEvent.takerTokenAddress = takerAssetData.tokenAddress;
-    // tslint:disable-next-line:no-unnecessary-type-assertion
-    exchangeCancelEvent.takerTokenId = bigNumbertoStringOrNull((takerAssetData as ERC721AssetData).tokenId);
-    return exchangeCancelEvent;
-}
-
-/**
- * Converts a raw event log for a cancelUpTo event into an
- * ExchangeCancelUpToEvent entity.
- * @param eventLog Raw event log (e.g. returned from contract-wrappers).
- */
-export function _convertToExchangeCancelUpToEvent(
-    eventLog: LogWithDecodedArgs<ExchangeCancelUpToEventArgs>,
-): ExchangeCancelUpToEvent {
-    const exchangeCancelUpToEvent = new ExchangeCancelUpToEvent();
-    exchangeCancelUpToEvent.contractAddress = eventLog.address as string;
-    exchangeCancelUpToEvent.blockNumber = eventLog.blockNumber as number;
-    exchangeCancelUpToEvent.logIndex = eventLog.logIndex as number;
-    exchangeCancelUpToEvent.rawData = eventLog.data as string;
-    exchangeCancelUpToEvent.transactionHash = eventLog.transactionHash;
-    exchangeCancelUpToEvent.makerAddress = eventLog.args.makerAddress;
-    exchangeCancelUpToEvent.senderAddress = eventLog.args.senderAddress;
-    exchangeCancelUpToEvent.orderEpoch = eventLog.args.orderEpoch;
-    return exchangeCancelUpToEvent;
-}
+export { parseExchangeCancelEvents, parseExchangeCancelUpToEvents, parseExchangeFillEvents } from './exchange_events';
+export { parseERC20ApprovalEvents } from './erc20_events';