EventStreamParserTests.swift

//
//  EventParserTests.swift
//  EventSourceTests
//
//  Created by Andres on 30/05/2019.
//  Copyright © 2019 inaka. All rights reserved.
//

import UIKit
import XCTest
@testable import EventSource

class EventStreamParserTests: XCTestCase {

	func testExtractingEvents() {
		let eventParser = EventStreamParser()
		let eventsString = """
		id: event-id-1
		data: event-data-first

		id: event-id-2
		data: event-data-second

		id: event-id-3
		data: event-data-third
		"""

		let events = eventParser.append(data: eventsString.data(using: .utf8))
		XCTAssertEqual(events.count, 2)
	}

	func testExtractingSplittedEvents() {
		let eventParser = EventStreamParser()
		let firstEventsStringPiece = """
		id: event-id-1
		data: event-data-first

		id: event
		"""

		var events = eventParser.append(data: firstEventsStringPiece.data(using: .utf8))
		XCTAssertEqual(events.count, 1)

		let secondEventsStringPiece = """
		-id-2
		data: event-data-second

		id: event-id-3
		data: event-data-third


		"""

		events = eventParser.append(data: secondEventsStringPiece.data(using: .utf8))
		XCTAssertEqual(events.count, 2)
	}

	// The following test streams are the samples introduced in the https://www.w3.org/TR/eventsource/ from section 7
	func testFirstW3StreamSample() {
		let eventParser = EventStreamParser()
		let eventString = """
		data: YHOO
		data: +2
		data: 10


		"""

		let events = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(events.count, 1)

		let event = events.first!
		XCTAssertEqual(event.id, nil)
		XCTAssertEqual(event.event, nil)
		XCTAssertEqual(event.retryTime, nil)
		XCTAssertEqual(event.data, "YHOO\n+2\n10")
	}

	// The first block has just a comment, and will fire nothing.
	// The second block has two fields with names "data" and "id" respectively; an event will be fired for this block.
	// The third block fires an event.
	// The last block is not fired as a new breakline is still missing to be parsed.
	func testSecondW3StreamSample() {
		let eventParser = EventStreamParser()
		let eventString = """
		: test stream

		data: first event
		id: 1

		data:second event
		id

		data:  third event

		"""

		let events = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(events.count, 2)

		let firstEvent = events[0]
		XCTAssertEqual(firstEvent.id, "1")
		XCTAssertEqual(firstEvent.event, nil)
		XCTAssertEqual(firstEvent.data, "first event")
		XCTAssertEqual(firstEvent.retryTime, nil)

		let secondEvent = events[1]
		XCTAssertEqual(secondEvent.id, "")
		XCTAssertEqual(secondEvent.event, nil)
		XCTAssertEqual(secondEvent.data, "second event")
		XCTAssertEqual(secondEvent.retryTime, nil)
	}

	// The first block fires an event with the data set to the empty string.
	// The middle block fires an event with the data set to a single newline character.
	// The last block fires an event with the data set to empty string.
	func testThirdW3StreamSample() {
		let eventParser = EventStreamParser()
		let eventString = """
		data

		data
		data

		data:


		"""

		let events = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(events.count, 3)

		let firstEvent = events[0]
		XCTAssertEqual(firstEvent.id, nil)
		XCTAssertEqual(firstEvent.event, nil)
		XCTAssertEqual(firstEvent.data, "")
		XCTAssertEqual(firstEvent.retryTime, nil)

		let secondEvent = events[1]
		XCTAssertEqual(secondEvent.id, nil)
		XCTAssertEqual(secondEvent.event, nil)
		XCTAssertEqual(secondEvent.data, "\n")
		XCTAssertEqual(secondEvent.retryTime, nil)

		let thirdEvent = events[2]
		XCTAssertEqual(thirdEvent.id, nil)
		XCTAssertEqual(thirdEvent.event, nil)
		XCTAssertEqual(thirdEvent.data, "")
		XCTAssertEqual(thirdEvent.retryTime, nil)
	}

	// The following stream fires two identical events:
	func testForthW3StreamSample() {
		let eventParser = EventStreamParser()
		let eventString = """
		data:test

		data: test


		"""

		let events = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(events.count, 2)

		let firstEvent = events[0]
		XCTAssertEqual(firstEvent.id, nil)
		XCTAssertEqual(firstEvent.event, nil)
		XCTAssertEqual(firstEvent.data, "test")
		XCTAssertEqual(firstEvent.retryTime, nil)

		let secondEvent = events[1]
		XCTAssertEqual(secondEvent.id, nil)
		XCTAssertEqual(secondEvent.event, nil)
		XCTAssertEqual(secondEvent.data, "test")
		XCTAssertEqual(secondEvent.retryTime, nil)
	}

	func testEventAfterCommentedLine() {
		let eventParser = EventStreamParser()
		let eventString = """
			:thump
			event: update
			data: data-from-the-event


		"""

		let events = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(events.count, 1)

		let firstEvent = events[0]
		XCTAssertEqual(firstEvent.id, nil)
		XCTAssertEqual(firstEvent.event, "update")
		XCTAssertEqual(firstEvent.data, "data-from-the-event")
		XCTAssertEqual(firstEvent.retryTime, nil)
	}

	func testCurrentBuffer() {
		let eventParser = EventStreamParser()
		let eventString = """
		-id-2
		data: event-data-second

		"""
		_ = eventParser.append(data: eventString.data(using: .utf8))
		XCTAssertEqual(eventParser.currentBuffer, eventString)
	}
}