swift-nio/Tests/NIOHTTP1Tests/HTTPResponseEncoderTest.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import XCTest
@testable import NIOCore
import NIOEmbedded
@testable import NIOHTTP1

private extension ByteBuffer {
    func assertContainsOnly(_ string: String) {
        let innerData = self.getString(at: self.readerIndex, length: self.readableBytes)!
        XCTAssertEqual(innerData, string)
    }
}

class HTTPResponseEncoderTests: XCTestCase {
    private func sendResponse(withStatus status: HTTPResponseStatus, andHeaders headers: HTTPHeaders) -> ByteBuffer {
        let channel = EmbeddedChannel()
        defer {
            XCTAssertEqual(true, try? channel.finish().isClean)
        }

        XCTAssertNoThrow(try channel.pipeline.addHandler(HTTPResponseEncoder()).wait())
        var switchingResponse = HTTPResponseHead(version: .http1_1, status: status)
        switchingResponse.headers = headers
        XCTAssertNoThrow(try channel.writeOutbound(HTTPServerResponsePart.head(switchingResponse)))
        do {
            if let buffer = try channel.readOutbound(as: ByteBuffer.self) {
                return buffer
            } else {
                fatalError("Could not read ByteBuffer from channel")
            }
        } catch {
            XCTFail("unexpected error: \(error)")
            var buf = channel.allocator.buffer(capacity: 16)
            buf.writeString("unexpected error: \(error)")
            return buf
        }
    }

    func testNoAutoHeadersFor101() throws {
        let writtenData = sendResponse(withStatus: .switchingProtocols, andHeaders: HTTPHeaders())
        writtenData.assertContainsOnly("HTTP/1.1 101 Switching Protocols\r\n\r\n")
    }

    func testNoAutoHeadersForCustom1XX() throws {
        let headers = HTTPHeaders([("Link", "</styles.css>; rel=preload; as=style")])
        let writtenData = sendResponse(withStatus: .custom(code: 103, reasonPhrase: "Early Hints"), andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 103 Early Hints\r\nLink: </styles.css>; rel=preload; as=style\r\n\r\n")
    }

    func testNoAutoHeadersFor204() throws {
        let writtenData = sendResponse(withStatus: .noContent, andHeaders: HTTPHeaders())
        writtenData.assertContainsOnly("HTTP/1.1 204 No Content\r\n\r\n")
    }

    func testNoContentLengthHeadersFor101() throws {
        let headers = HTTPHeaders([("content-length", "0")])
        let writtenData = sendResponse(withStatus: .switchingProtocols, andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 101 Switching Protocols\r\n\r\n")
    }

    func testNoContentLengthHeadersForCustom1XX() throws {
        let headers = HTTPHeaders([("Link", "</styles.css>; rel=preload; as=style"), ("content-length", "0")])
        let writtenData = sendResponse(withStatus: .custom(code: 103, reasonPhrase: "Early Hints"), andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 103 Early Hints\r\nLink: </styles.css>; rel=preload; as=style\r\n\r\n")
    }

    func testNoContentLengthHeadersFor204() throws {
        let headers = HTTPHeaders([("content-length", "0")])
        let writtenData = sendResponse(withStatus: .noContent, andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 204 No Content\r\n\r\n")
    }

    func testNoTransferEncodingHeadersFor101() throws {
        let headers = HTTPHeaders([("transfer-encoding", "chunked")])
        let writtenData = sendResponse(withStatus: .switchingProtocols, andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 101 Switching Protocols\r\n\r\n")
    }

    func testNoTransferEncodingHeadersForCustom1XX() throws {
        let headers = HTTPHeaders([("Link", "</styles.css>; rel=preload; as=style"), ("transfer-encoding", "chunked")])
        let writtenData = sendResponse(withStatus: .custom(code: 103, reasonPhrase: "Early Hints"), andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 103 Early Hints\r\nLink: </styles.css>; rel=preload; as=style\r\n\r\n")
    }

    func testNoTransferEncodingHeadersFor204() throws {
        let headers = HTTPHeaders([("transfer-encoding", "chunked")])
        let writtenData = sendResponse(withStatus: .noContent, andHeaders: headers)
        writtenData.assertContainsOnly("HTTP/1.1 204 No Content\r\n\r\n")
    }

    func testNoChunkedEncodingForHTTP10() throws {
        let channel = EmbeddedChannel()
        defer {
            XCTAssertEqual(true, try? channel.finish().isClean)
        }

        XCTAssertNoThrow(try channel.pipeline.addHandler(HTTPResponseEncoder()).wait())

        // This response contains neither Transfer-Encoding: chunked or Content-Length.
        let response = HTTPResponseHead(version: .http1_0, status: .ok)
        XCTAssertNoThrow(try channel.writeOutbound(HTTPServerResponsePart.head(response)))
        guard let b = try channel.readOutbound(as: ByteBuffer.self) else {
            XCTFail("Could not read byte buffer")
            return
        }
        let writtenResponse = b.getString(at: b.readerIndex, length: b.readableBytes)!
        XCTAssertEqual(writtenResponse, "HTTP/1.0 200 OK\r\n\r\n")
    }
}