CSV/Tests/CSVTests/DecoderTests.swift

import XCTest
import CSV

final class DecoderTests: XCTestCase {
    func testAsyncDecode() throws {
        var people: [Person] = []
        let contentLength = chunks.reduce(0) { $0 + $1.count }
        let decoder = CSVDecoder().async(for: Person.self, length: contentLength) { person in
            people.append(person)
        }

        for chunk in chunks.map({ Array($0.utf8) }) {
            try decoder.decode(chunk)
        }

        XCTAssertEqual(people.count, 6)

        XCTAssertEqual(people[0], Person(firstName: "Caleb", lastName: "Kleveter", age: 18, gender: .male, tagLine: "😜"))
        XCTAssertEqual(people[1], Person(
            firstName: "Benjamin",
            lastName: "Franklin",
            age: 269,
            gender: .male,
            tagLine: "A penny saved is a penny earned"
        ))
        XCTAssertEqual(people[2], Person(firstName: "Doc", lastName: "Holliday", age: 174, gender: .male, tagLine: "Bang"))
        XCTAssertEqual(people[3], Person(firstName: "Grace", lastName: "Hopper", age: 119, gender: .female, tagLine: nil))
        XCTAssertEqual(people[4], Person(
            firstName: "Anne",
            lastName: "Shirley",
            age: 141,
            gender: .female,
            tagLine: "God's in His heaven,\nall's right with the world"
        ))
        XCTAssertEqual(people[5], Person(firstName: "TinTin", lastName: nil, age: 16, gender: .male, tagLine: "Great snakes!"))
    }

    func testAsyncDecodeSpeed() throws {
        let bytes = chunks.map { Array($0.utf8) }
        let contentLength = chunks.reduce(0) { $0 + $1.count }

        // Baseline: 0.062
        measure {
            for _ in 0..<1_000 {
                let decoder = CSVDecoder().async(for: Person.self, length: contentLength) { _ in return }
                do {
                    try bytes.forEach(decoder.decode)
                } catch let error as DecodingError {
                    XCTFail(error.failureReason ?? "No failure reason")
                    error.errorDescription.map { print($0) }
                    error.recoverySuggestion.map { print($0) }
                } catch let error {
                    XCTFail(error.localizedDescription)
                }
            }
        }
    }

    func testSyncDecode() throws {
        let decoder = CSVDecoder().sync
        let people = try decoder.decode(Person.self, from: Data(data.utf8))

        XCTAssertEqual(people.count, 6)

        XCTAssertEqual(people[0], Person(firstName: "Caleb", lastName: "Kleveter", age: 18, gender: .male, tagLine: "😜"))
        XCTAssertEqual(people[1], Person(
            firstName: "Benjamin",
            lastName: "Franklin",
            age: 269,
            gender: .male,
            tagLine: "A penny saved is a penny earned"
        ))
        XCTAssertEqual(people[2], Person(firstName: "Doc", lastName: "Holliday", age: 174, gender: .male, tagLine: "Bang"))
        XCTAssertEqual(people[3], Person(firstName: "Grace", lastName: "Hopper", age: 119, gender: .female, tagLine: nil))
        XCTAssertEqual(people[4], Person(
            firstName: "Anne",
            lastName: "Shirley",
            age: 141,
            gender: .female,
            tagLine: "God's in His heaven,\nall's right with the world"
        ))
        XCTAssertEqual(people[5], Person(firstName: "TinTin", lastName: nil, age: 16, gender: .male, tagLine: "Great snakes!"))
    }

    func testSyncDecodeSpeed() throws {
        let csv = Data(data.utf8)

        // Baseline: 0.066
        measure {
            for _ in 0..<1_000 {
                let decoder = CSVDecoder().sync
                do {
                    _ = try decoder.decode(Person.self, from: csv)
                } catch let error as DecodingError {
                    XCTFail(error.failureReason ?? "No failure reason")
                    error.errorDescription.map { print($0) }
                    error.recoverySuggestion.map { print($0) }
                } catch let error {
                    XCTFail(error.localizedDescription)
                }
            }
        }
    }
}

fileprivate struct Person: Codable, Equatable {
    let firstName: String
    let lastName: String?
    let age: Int
    let gender: Gender
    let tagLine: String?

    enum Gender: String, Codable {
        case female = "F"
        case male = "M"
    }

    enum CodingKeys: String, CodingKey {
        case firstName = "first name"
        case lastName = "last_name"
        case age
        case gender
        case tagLine
    }
}