rust-web-server 18.8.2

<!doctype html>
<meta charset="utf-8">
<title>rws gRPC-web check</title>
<script>
// gRPC-web calls to echo.Echo (ci/e2e/grpc/proto/echo.proto) with fetch, the
// protobuf encoded by hand (Msg { string text = 1; }). window.result is set
// to "ok" or to what went wrong.
const encoder = new TextEncoder(), decoder = new TextDecoder();

function msg(text) {
  const bytes = encoder.encode(text);
  return Uint8Array.of(0x0a, bytes.length, ...bytes); // field 1, length-delimited (< 128 bytes)
}
function frame(payload) {
  const out = new Uint8Array(5 + payload.length);
  new DataView(out.buffer).setUint32(1, payload.length);
  out.set(payload, 5);
  return out;
}
function frames(bytes) { // -> { messages: [text], trailers: {name: value} }
  const messages = [], trailers = {};
  for (let at = 0; at < bytes.length;) {
    const flag = bytes[at], len = new DataView(bytes.buffer, bytes.byteOffset + at + 1, 4).getUint32(0);
    const body = bytes.subarray(at + 5, at + 5 + len);
    if (flag & 0x80) {
      for (const line of decoder.decode(body).split("\r\n").filter(Boolean)) {
        const i = line.indexOf(":");
        trailers[line.slice(0, i)] = line.slice(i + 1);
      }
    } else {
      messages.push(decoder.decode(body.subarray(2, 2 + body[1])));
    }
    at += 5 + len;
  }
  return { messages, trailers };
}
const b64 = bytes => btoa(String.fromCharCode(...bytes));
const unb64 = text => Uint8Array.from(atob(text), c => c.charCodeAt(0));

window.progress = [];
async function call(method, text, mode) {
  window.progress.push(`${method}(${text}, ${mode})`);
  const body = frame(msg(text));
  const response = await fetch(`/echo.Echo/${method}`, {
    signal: AbortSignal.timeout(10000),
    method: "POST",
    headers: { "content-type": mode === "text" ? "application/grpc-web-text" : "application/grpc-web+proto", "x-grpc-web": "1" },
    body: mode === "text" ? b64(body) : body,
  });
  window.progress.push(`  head ${response.status} ${response.headers.get("content-type")}`);
  let bytes = new Uint8Array(await response.arrayBuffer());
  window.progress.push(`  body ${bytes.length} bytes`);
  if (mode === "text") bytes = unb64(decoder.decode(bytes));
  return { status: response.status, headers: response.headers, ...frames(bytes) };
}

async function check() {
  const expect = (label, ok, got) => { if (!ok) throw new Error(`${label}: ${JSON.stringify(got)}`); };
  let r = await call("Unary", "hi", "binary");
  expect("unary", r.messages.join() === "hi" && r.trailers["grpc-status"] === "0", r);
  r = await call("ServerStream", "s", "binary");
  expect("server streaming", r.messages.join() === "s-0,s-1,s-2" && r.trailers["grpc-status"] === "0", r);
  r = await call("ServerStream", "fail", "binary");
  expect("status after a message", r.messages.join() === "fail-0" && r.trailers["grpc-status"] === "10", r);
  r = await call("Unary", "text", "text");
  expect("grpc-web-text", r.messages.join() === "text" && r.trailers["grpc-status"] === "0", r);
  r = await call("Fail", "x", "binary");
  expect("trailers-only error", r.headers.get("grpc-status") === "3" && r.headers.get("grpc-message") === "boom", Object.fromEntries(r.headers));
  return "ok";
}
check().then(result => window.result = result, error => window.result = String(error));
</script>