websockets_client.c

#include <assert.h>
#include <emscripten/websocket.h>
#include <stdio.h>
#include <stdlib.h>

EM_BOOL WebSocketOpen(int eventType, const EmscriptenWebSocketOpenEvent *e, void *userData)
{
    printf("open(eventType=%d, userData=%d)\n", eventType, (int)userData);

    emscripten_websocket_send_utf8_text(e->socket, "hello on the other side");

    char data[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    emscripten_websocket_send_binary(e->socket, data, sizeof(data));

    return 0;
}

EM_BOOL WebSocketClose(int eventType, const EmscriptenWebSocketCloseEvent *e, void *userData)
{
    printf("close(eventType=%d, wasClean=%d, code=%d, reason=%s, userData=%d)\n", eventType, e->wasClean, e->code,
           e->reason, (int)userData);
    return 0;
}

EM_BOOL WebSocketError(int eventType, const EmscriptenWebSocketErrorEvent *e, void *userData)
{
    printf("error(eventType=%d, userData=%d)\n", eventType, (int)userData);
    return 0;
}

static int passed = 0;

EM_BOOL WebSocketMessage(int eventType, const EmscriptenWebSocketMessageEvent *e, void *userData)
{
    printf("message(eventType=%d, userData=%d, data=%p, numBytes=%d, isText=%d)\n", eventType, (int)userData, e->data,
           e->numBytes, e->isText);
    if (e->isText) {
        printf("text data: \"%s\"\n", e->data);
#ifdef REPORT_RESULT
        if (!!strcmp((const char *)e->data, "hello on the other side")) REPORT_RESULT(-1);
        passed += 1;
#endif
    }
    else {
        printf("binary data:");
        for (int i = 0; i < e->numBytes; ++i) {
            printf(" %02X", e->data[i]);
#ifdef REPORT_RESULT
            if (e->data[i] != i) REPORT_RESULT(-2);
#endif
        }
        printf("\n");
        passed += 100;

        emscripten_websocket_close(e->socket, 0, 0);
        emscripten_websocket_delete(e->socket);
#ifdef REPORT_RESULT
        printf("%d\n", passed);
        REPORT_RESULT(passed);
#endif
    }
    return 0;
}

int main()
{
    if (!emscripten_websocket_is_supported()) {
        printf("WebSockets are not supported, cannot continue!\n");
        exit(1);
    }

    EmscriptenWebSocketCreateAttributes attr;
    emscripten_websocket_init_create_attributes(&attr);

    const char *url = "ws://localhost:8080/";
    attr.url = url;
    attr.protocols = "binary,base64"; // We don't really use a special protocol on the server backend in this test, but
                                      // check that it can be passed.

    EMSCRIPTEN_WEBSOCKET_T socket = emscripten_websocket_new(&attr);
    if (socket <= 0) {
        printf("WebSocket creation failed, error code %d!\n", (EMSCRIPTEN_RESULT)socket);
        exit(1);
    }

    // URL:
    int urlLength = 0;
    EMSCRIPTEN_RESULT res = emscripten_websocket_get_url_length(socket, &urlLength);

    char *url2 = malloc(urlLength);
    res = emscripten_websocket_get_url(socket, url2, urlLength);
    printf("url: %s, verified: %s, length: %d\n", url, url2, urlLength);

    // Protocol:
    int protocolLength = 0;
    res = emscripten_websocket_get_protocol_length(socket, &protocolLength);

    char *protocol = malloc(protocolLength);
    res = emscripten_websocket_get_protocol(socket, protocol, protocolLength);
    // test that it comes out as an empty string at least.

    // Extensions:
    int extensionsLength = 0;
    res = emscripten_websocket_get_extensions_length(socket, &extensionsLength);

    char *extensions = malloc(extensionsLength);
    res = emscripten_websocket_get_extensions(socket, extensions, extensionsLength);

    emscripten_websocket_set_onopen_callback(socket, (void *)42, WebSocketOpen);
    emscripten_websocket_set_onclose_callback(socket, (void *)43, WebSocketClose);
    emscripten_websocket_set_onerror_callback(socket, (void *)44, WebSocketError);
    emscripten_websocket_set_onmessage_callback(socket, (void *)45, WebSocketMessage);
}