feat: get the portfolio creation event

src/api/entities/NumberedPortfolio.ts

@@ -3,6 +3,9 @@ import BigNumber from 'bignumber.js';
 import { Portfolio } from '~/api/entities';
 import { deletePortfolio, renamePortfolio, RenamePortfolioParams } from '~/api/procedures';
 import { Context, TransactionQueue } from '~/base';
+import { eventByIndexedArgs } from '~/middleware/queries';
+import { EventIdEnum, ModuleIdEnum, Query } from '~/middleware/types';
+import { Ensured, EventIdentifier } from '~/types';
 import { bytesToString, numberToU64 } from '~/utils';
 
 export interface UniqueIdentifiers {
@@ -83,4 +86,40 @@ export class NumberedPortfolio extends Portfolio {
     const rawPortfolioName = await portfolio.portfolios(did, numberToU64(id, context));
     return bytesToString(rawPortfolioName);
   }
+
+  /**
+   * Retrieve the identifier data (block number, date and event index) of the event that was emitted when this portfolio was created
+   *
+   * @note uses the middleware
+   * @note there is a possibility that the data is not ready by the time it is requested. In that case, `null` is returned
+   */
+  public async createdAt(): Promise<EventIdentifier | null> {
+    const {
+      owner: { did },
+      id,
+      context,
+    } = this;
+
+    const result = await context.queryMiddleware<Ensured<Query, 'eventByIndexedArgs'>>(
+      eventByIndexedArgs({
+        moduleId: ModuleIdEnum.Portfolio,
+        eventId: EventIdEnum.PortfolioCreated,
+        eventArg0: did,
+        eventArg1: id.toString(),
+      })
+    );
+
+    if (result.data.eventByIndexedArgs) {
+      // TODO remove null check once types fixed
+      /* eslint-disable @typescript-eslint/no-non-null-assertion */
+      return {
+        blockNumber: new BigNumber(result.data.eventByIndexedArgs.block_id!),
+        blockDate: result.data.eventByIndexedArgs.block!.datetime!,
+        eventIndex: result.data.eventByIndexedArgs.event_idx!,
+      };
+      /* eslint-enabled @typescript-eslint/no-non-null-assertion */
+    }
+
+    return null;
+  }
 }

src/api/entities/__tests__/NumberedPortfolio.ts

@@ -4,6 +4,8 @@ import sinon from 'sinon';
 import { Entity, Identity, NumberedPortfolio } from '~/api/entities';
 import { deletePortfolio, renamePortfolio } from '~/api/procedures';
 import { Context, TransactionQueue } from '~/base';
+import { eventByIndexedArgs } from '~/middleware/queries';
+import { EventIdEnum, ModuleIdEnum } from '~/middleware/types';
 import { dsMockUtils } from '~/testUtils/mocks';
 
 describe('Numberedortfolio class', () => {
@@ -107,4 +109,45 @@ describe('Numberedortfolio class', () => {
       expect(result).toEqual(portfolioName);
     });
   });
+
+  describe('method: createdAt', () => {
+    const id = new BigNumber(1);
+    const did = 'someDid';
+    const variables = {
+      moduleId: ModuleIdEnum.Portfolio,
+      eventId: EventIdEnum.PortfolioCreated,
+      eventArg0: did,
+      eventArg1: id.toString(),
+    };
+
+    test('should return the event identifier object of the portfolio creation', async () => {
+      const blockNumber = new BigNumber(1234);
+      const blockDate = new Date('4/14/2020');
+      const eventIdx = 1;
+      const fakeResult = { blockNumber, blockDate, eventIndex: eventIdx };
+      const numberedPortfolio = new NumberedPortfolio({ id, did }, context);
+
+      dsMockUtils.createApolloQueryStub(eventByIndexedArgs(variables), {
+        /* eslint-disable @typescript-eslint/camelcase */
+        eventByIndexedArgs: {
+          block_id: blockNumber.toNumber(),
+          block: { datetime: blockDate },
+          event_idx: eventIdx,
+        },
+        /* eslint-enable @typescript-eslint/camelcase */
+      });
+
+      const result = await numberedPortfolio.createdAt();
+
+      expect(result).toEqual(fakeResult);
+    });
+
+    test('should return null if the query result is empty', async () => {
+      const numberedPortfolio = new NumberedPortfolio({ id, did }, context);
+
+      dsMockUtils.createApolloQueryStub(eventByIndexedArgs(variables), {});
+      const result = await numberedPortfolio.createdAt();
+      expect(result).toBeNull();
+    });
+  });
 });