Demonstrates Issue 1410 in Swift Protobuf

SwiftProtobufIssue1410Tests.swift

//
//  SwiftProtobufIssue1410Tests.swift
//
//  Created by Will Temperley on 26/06/2023.
//

import Foundation
import XCTest
import SwiftProtobuf

class ParseBinaryDelimitedProtobufFileTest: XCTestCase {
    
    /**
    Creates a URL for a temporary file on disk. Registers a teardown block to
    delete a file at that URL (if one exists) during test teardown.
    */
    func temporaryFileURL() -> URL {
        
        let directory = NSTemporaryDirectory()
        let filename = UUID().uuidString
        let fileURL = URL(fileURLWithPath: directory).appendingPathComponent(filename)
        
        addTeardownBlock {
            do {
                let fileManager = FileManager.default
                if fileManager.fileExists(atPath: fileURL.path) {
                    try fileManager.removeItem(at: fileURL)
                    XCTAssertFalse(fileManager.fileExists(atPath: fileURL.path))
                }
            } catch {
                XCTFail("Error while deleting temporary file: \(error)")
            }
        }
        return fileURL
    }
    
    
    func writeTestProtobuf(_ fileURL: URL) throws {
        let outputStream = OutputStream(url: fileURL, append: false)!
        outputStream.open()
        for index in 1...1000 {
            var message = SearchRequest()
            message.pageNumber = Int64(index)
            message.resultsPerPage = 100
            try BinaryDelimited.serialize(message: message, to: outputStream)
        }
        outputStream.close()
    }
    
    //Reading directly from a file fails with a truncated error
    func testReadDirectFromFile() throws {
        let fileURL = temporaryFileURL()
        try writeTestProtobuf(fileURL)
        
        let inputStream = InputStream(url: fileURL)!
        inputStream.open()
        var messages = [SearchRequest]()
        while (inputStream.hasBytesAvailable) {
            let message = try BinaryDelimited.parse(messageType: SearchRequest.self, from: inputStream)
            messages.append(message)
        }
        inputStream.close()
        assert(messages.count == 1000)
    }
    
    //Reading the file contents into a data object first runs fine
    func testReadFileContentsToData() throws {
        let fileURL = temporaryFileURL()
        try writeTestProtobuf(fileURL)
        
        let data = try Data(contentsOf: fileURL)
        let inputStream = InputStream(data: data)
        inputStream.open()
        var messages = [SearchRequest]()
        while (inputStream.hasBytesAvailable) {
            let message = try BinaryDelimited.parse(messageType: SearchRequest.self, from: inputStream)
            messages.append(message)
        }
        inputStream.close()
        assert(messages.count == 1000)
    }
}

// If the compiler emits an error on this type, it is because this file
// was generated by a version of the `protoc` Swift plug-in that is
// incompatible with the version of SwiftProtobuf to which you are linking.
// Please ensure that you are building against the same version of the API
// that was used to generate this file.
fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAPIVersionCheck {
  struct _2: SwiftProtobuf.ProtobufAPIVersion_2 {}
  typealias Version = _2
}

struct SearchRequest {
  // SwiftProtobuf.Message conformance is added in an extension below. See the
  // `Message` and `Message+*Additions` files in the SwiftProtobuf library for
  // methods supported on all messages.

  var query: String = String()

  var pageNumber: Int64 = 0

  var resultsPerPage: Int64 = 0

  var unknownFields = SwiftProtobuf.UnknownStorage()

  init() {}
}

#if swift(>=5.5) && canImport(_Concurrency)
extension SearchRequest: @unchecked Sendable {}
#endif  // swift(>=5.5) && canImport(_Concurrency)

// MARK: - Code below here is support for the SwiftProtobuf runtime.

extension SearchRequest: SwiftProtobuf.Message, SwiftProtobuf._MessageImplementationBase, SwiftProtobuf._ProtoNameProviding {
  static let protoMessageName: String = "SearchRequest"
  static let _protobuf_nameMap: SwiftProtobuf._NameMap = [
    1: .same(proto: "query"),
    2: .standard(proto: "page_number"),
    3: .standard(proto: "results_per_page"),
  ]

  mutating func decodeMessage<D: SwiftProtobuf.Decoder>(decoder: inout D) throws {
    while let fieldNumber = try decoder.nextFieldNumber() {
      // The use of inline closures is to circumvent an issue where the compiler
      // allocates stack space for every case branch when no optimizations are
      // enabled. https://github.com/apple/swift-protobuf/issues/1034
      switch fieldNumber {
      case 1: try { try decoder.decodeSingularStringField(value: &self.query) }()
      case 2: try { try decoder.decodeSingularInt64Field(value: &self.pageNumber) }()
      case 3: try { try decoder.decodeSingularInt64Field(value: &self.resultsPerPage) }()
      default: break
      }
    }
  }

  func traverse<V: SwiftProtobuf.Visitor>(visitor: inout V) throws {
    if !self.query.isEmpty {
      try visitor.visitSingularStringField(value: self.query, fieldNumber: 1)
    }
    if self.pageNumber != 0 {
      try visitor.visitSingularInt64Field(value: self.pageNumber, fieldNumber: 2)
    }
    if self.resultsPerPage != 0 {
      try visitor.visitSingularInt64Field(value: self.resultsPerPage, fieldNumber: 3)
    }
    try unknownFields.traverse(visitor: &visitor)
  }

  static func ==(lhs: SearchRequest, rhs: SearchRequest) -> Bool {
    if lhs.query != rhs.query {return false}
    if lhs.pageNumber != rhs.pageNumber {return false}
    if lhs.resultsPerPage != rhs.resultsPerPage {return false}
    if lhs.unknownFields != rhs.unknownFields {return false}
    return true
  }
}