Omit unexported instruments from datasetId lookup

Author: thaaddeus

src/instrumentinfo.ts

@@ -66,7 +66,10 @@ export async function findInstrumentSymbols(
 
       return {
         exchange,
-        symbols: instruments.map((instrument) => (selector === 'datasetId' ? (instrument.datasetId ?? instrument.id) : instrument.id))
+        symbols:
+          selector === 'datasetId'
+            ? instruments.flatMap((instrument) => instrument.datasetId ?? [])
+            : instruments.map((instrument) => instrument.id)
       }
     })
   )
@@ -112,7 +115,7 @@ export type UnderlyingType = 'native' | 'equity' | 'commodity' | 'fixed_income'
 export interface InstrumentInfo {
   /** symbol id */
   id: string
-  /** dataset symbol id, may differ from id */
+  /** dataset symbol id, present after the symbol appears in exported dataset metadata */
   datasetId?: string
   /** exchange id */
   exchange: string

test/instrumentinfo.test.ts

@@ -21,14 +21,14 @@ describe('findInstrumentSymbols', () => {
     jest.restoreAllMocks()
   })
 
-  test('returns dataset ids and falls back to id when datasetId is omitted', async () => {
+  test('returns only instruments with dataset ids when datasetId selector is used', async () => {
     global.fetch = createFetchMock(
       new Response(JSON.stringify([{ id: 'btcusdt', datasetId: 'BTCUSDT' }, { id: 'ethusdt' }]), { status: 200 })
     )
     init({ endpoint: 'https://example.com/v1' })
 
     await expect(findInstrumentSymbols(['binance'], { active: true }, 'datasetId')).resolves.toEqual([
-      { exchange: 'binance', symbols: ['BTCUSDT', 'ethusdt'] }
+      { exchange: 'binance', symbols: ['BTCUSDT'] }
     ])
   })