apacheGH-37744: [Swift] Add test for arrow flight doGet FlightData

swift/ArrowFlight/Tests/ArrowFlightTests/FlightTest.swift

@@ -225,6 +225,25 @@ public class FlightClientTester {
  XCTAssertEqual(num_call, 1)
  }
 
+ func doGetTestFlightData() async throws {
+ let ticket = FlightTicket("flight_ticket test".data(using: .utf8)!)
+ var num_call = 0
+ try await client?.doGet(ticket, flightDataClosure: { flightData in
+ let reader = ArrowReader();
+ let result = reader.fromStream(flightData.dataBody)
+ switch result {
+ case .success(let rb):
+ XCTAssertEqual(rb.schema?.fields.count, 3)
+ XCTAssertEqual(rb.batches[0].length, 4)
+ num_call += 1
+ case .failure(let error):
+ throw error
+ }
+ })
+
+ XCTAssertEqual(num_call, 1)
+ }
+
  func doPutTest() async throws {
  let rb = try makeRecordBatch()
  var num_call = 0
@@ -290,6 +309,7 @@ final class FlightTest: XCTestCase {
  try await clientImpl.doActionTest()
  try await clientImpl.getSchemaTest()
  try await clientImpl.doGetTest()
+ try await clientImpl.doGetTestFlightData()
  try await clientImpl.doPutTest()
  try await clientImpl.doExchangeTest()