Method multipartUpload

Tests/Libraries/Http/HttpAsyncClientTest.cpp:2104–2180

    const uint16_t port = report.mapPort(26107);

    ThreadPool threadPool;
    if (loop.needsThreadPoolForFileOperations())
    {
        SC_TEST_EXPECT(threadPool.create(2));
    }
    SC_TEST_EXPECT(httpServer.init(Span<ServerConnection>(connections)));
    SC_TEST_EXPECT(httpServer.start(loop, "127.0.0.1", port));
    SC_TEST_EXPECT(fileServer.init(threadPool, loop, webServerFolder));
    struct ServerContext
    {
        HttpAsyncFileServer&                 fileServer;
        HttpAsyncFileServer::StreamQueue<2>* streams;
    } serverCtx = {fileServer, streams};

    httpServer.onRequest = [this, &serverCtx](HttpConnection& connection)
    {
        SC_TEST_EXPECT(
            serverCtx.fileServer.handleRequest(serverCtx.streams[connection.getConnectionID().getIndex()], connection));
    };

    ClientConnection  clientStorage;
    HttpAsyncClient   client;
    ResponseCollector collector;
    TimeoutGuard      timeout;
    FileSystem        fs;
    struct Context
    {
        ResponseCollector& collector;
        HttpAsyncServer&   httpServer;
        FileSystem&        fs;
    } ctx = {collector, httpServer, fs};

    SC_TEST_EXPECT(fs.init(webServerFolder));
    SC_TEST_EXPECT(client.init(clientStorage));
    String url = StringEncoding::Ascii;
    SC_TEST_EXPECT(StringBuilder::format(url, "http://127.0.0.1:{}/upload", port));
    HttpMultipartWriter writer;
    SC_TEST_EXPECT(writer.setBoundary("----SCMultipartBoundary"));
    SC_TEST_EXPECT(writer.addFile("file", "multipart-public.txt", StringSpan("MultipartContent").toCharSpan()));

    client.onResponse = [this, &ctx](HttpAsyncClientResponse& response)
    {
        ctx.collector.attach(response,
                             [this, &ctx](HttpAsyncClientResponse& completedResponse)
                             {
                                 ctx.collector.detach();
                                 SC_TEST_EXPECT(completedResponse.getParser().statusCode == 201);
                                 String content;
                                 SC_TEST_EXPECT(ctx.fs.read("multipart-public.txt", content));
                                 SC_TEST_EXPECT(content == "MultipartContent");
                                 SC_TEST_EXPECT(ctx.fs.removeFile("multipart-public.txt"));
                                 SC_TEST_EXPECT(ctx.httpServer.stop());
                             });
    };
    client.onError = [this](Result result) { SC_TEST_EXPECT(result); };

    SC_TEST_EXPECT(timeout.start(loop, TimeMs{2000}));