Fetch

FetchResponse response = await fetch.Send(new FetchRequest
{
    Url = "https://jsonplaceholder.typicode.com/todos/1",
});

if (response.Ok)
{
    var json = Encoding.UTF8.GetString(response.Body);
}

var request = new FetchRequest
{
    Url = "https://jsonplaceholder.typicode.com/posts",
    Method = "POST",
    Headers = new() { ["Content-Type"] = "application/json; charset=utf-8" },
    Body = Encoding.UTF8.GetBytes("{\"title\":\"Bit.Butil\",\"userId\":1}"),
    Credentials = "omit",   // "omit" | "same-origin" | "include"
    Mode = "cors",          // "cors" | "no-cors" | "same-origin" | "navigate"
    Cache = "no-store",     // "default" | "no-store" | "reload" | "no-cache" | ...
    Redirect = "follow",    // "follow" | "error" | "manual"
};

FetchResponse response = await fetch.Send(request);

var headers = new FetchHeaders()
    .Append("Accept", "application/json")
    .Append("X-Trace", "one")
    .Append("X-Trace", "two");

headers.GetAll("x-trace");   // ["one", "two"] - case-insensitive
headers.Get("X-Trace");      // "one, two"
headers.Set("Accept", "text/plain");   // replaces every Accept

// still assignable from - and to - a dictionary
FetchRequest request = new() { Headers = new() { ["Content-Type"] = "application/json" } };
Dictionary<string, string> flat = request.Headers;

FetchResponse response = await fetch.Send(new FetchRequest { Url = url });

// response.Redirected - true when at least one redirect got us here
// response.Type       - "basic" | "cors" | "opaque" | "opaqueredirect" | "error"
// response.Error      - set instead of throwing when the network or CORS said no

var opaque = await fetch.Send(new FetchRequest { Url = url, Mode = "no-cors" });
// opaque.Type == "opaque", opaque.Status == 0, opaque.Body is empty

if (await fetch.SupportsStreamingUpload() is false) return;   // fall back to Send

await using var file = File.OpenRead(path);

FetchResponse response = await fetch.SendStream(
    new FetchRequest
    {
        Url = "https://example.com/upload",
        Method = "POST",
        Headers = new() { ["Content-Type"] = "application/octet-stream" },
    },
    file,
    onProgress: p => { /* p.Loaded of p.Total handed to the browser */ });

var response = await fetch.Send(
    new FetchRequest { Url = "https://example.com/large-file" },
    onProgress: p =>
    {
        var percent = p.Total.HasValue ? $"{100.0 * p.Loaded / p.Total.Value:F0}%" : "?";
        // update UI: p.Loaded of p.Total bytes
    });

using var cts = new CancellationTokenSource();

var responseTask = fetch.Send(
    new FetchRequest { Url = "https://example.com/large-file" },
    cancellationToken: cts.Token);

cts.Cancel(); // abort mid-flight

var response = await responseTask;
// response.Aborted == true

@inject Bit.Butil.Fetch fetch

@code {
    private AbortableFetch? handle;

    private async Task Start() =>
        handle = await fetch.Start(new FetchRequest
        {
            Url = "https://example.com/large-file",
        });

    // Nothing waits for the response, so this is the only way to stop the transfer.
    private async Task Cancel() => await handle!.Abort();
}