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

2 files changed, 27 insertions, 0 deletions

diff --git a/packages/pipeline/src/entities/erc20_approval_event.ts b/packages/pipeline/src/entities/erc20_approval_event.ts
new file mode 100644
index 000000000..69cdfcb0b
--- /dev/null
+++ b/packages/pipeline/src/entities/erc20_approval_event.ts
@@ -0,0 +1,26 @@
+import { BigNumber } from '@0x/utils';
+import { Column, Entity, PrimaryColumn } from 'typeorm';
+
+import { bigNumberTransformer, numberToBigIntTransformer } from '../utils';
+
+@Entity({ name: 'erc20_approval_events', schema: 'raw' })
+export class ERC20ApprovalEvent {
+    @PrimaryColumn({ name: 'token_address' })
+    public tokenAddress!: string;
+    @PrimaryColumn({ name: 'log_index' })
+    public logIndex!: number;
+    @PrimaryColumn({ name: 'block_number', transformer: numberToBigIntTransformer })
+    public blockNumber!: number;
+
+    @Column({ name: 'raw_data' })
+    public rawData!: string;
+
+    @Column({ name: 'transaction_hash' })
+    public transactionHash!: string;
+    @Column({ name: 'owner_address' })
+    public ownerAddress!: string;
+    @Column({ name: 'spender_address' })
+    public spenderAddress!: string;
+    @Column({ name: 'amount', type: 'numeric', transformer: bigNumberTransformer })
+    public amount!: BigNumber;
+}
diff --git a/packages/pipeline/src/entities/index.ts b/packages/pipeline/src/entities/index.ts
index db0814e38..cc3de78bb 100644
--- a/packages/pipeline/src/entities/index.ts
+++ b/packages/pipeline/src/entities/index.ts
@@ -14,5 +14,6 @@ export { SraOrdersObservedTimeStamp, createObservedTimestampForOrder } from './s
 export { TokenMetadata } from './token_metadata';
 export { TokenOrderbookSnapshot } from './token_order';
 export { Transaction } from './transaction';
+export { ERC20ApprovalEvent } from './erc20_approval_event';
 
 export type ExchangeEvent = ExchangeFillEvent | ExchangeCancelEvent | ExchangeCancelUpToEvent;