| 1 | package callstest |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "bytes" |
| 6 | "context" |
| 7 | "encoding/json" |
| 8 | "io" |
| 9 | "net" |
| 10 | "net/http" |
| 11 | "strings" |
| 12 | "sync" |
| 13 | "syscall" |
| 14 | "testing" |
| 15 | "time" |
| 16 | ) |
| 17 | |
| 18 | // sseReader is a browser's EventSource, near enough: one open GET |
| 19 | // against the harness's real server, its lines parsed into events on a |
| 20 | // channel while the test goroutine reads them one at a time. |
| 21 | type sseReader struct { |
| 22 | t *testing.T |
| 23 | cancel context.CancelFunc |
| 24 | body io.ReadCloser |
| 25 | events chan sseEvent |
| 26 | hb chan struct{} |
| 27 | done chan struct{} |
| 28 | closing chan struct{} |
| 29 | once sync.Once |
| 30 | } |
| 31 | |
| 32 | type sseEvent struct { |
| 33 | name string |
| 34 | data []byte |
| 35 | } |
| 36 | |
| 37 | // stream opens an SSE stream and fails the test unless the server |
| 38 | // accepted it. A refusal is read with c.get instead, which needs no |
| 39 | // socket: the status and the JSON body are the whole answer (§4.5). |
| 40 | func (c *client) stream(target string) *sseReader { |
| 41 | c.t.Helper() |
| 42 | srv := c.x.server() |
| 43 | ctx, cancel := context.WithCancel(context.Background()) |
| 44 | req, err := http.NewRequestWithContext(ctx, http.MethodGet, srv.URL+target, nil) |
| 45 | if err != nil { |
| 46 | cancel() |
| 47 | c.t.Fatal(err) |
| 48 | } |
| 49 | for _, ck := range c.cookies { |
| 50 | req.AddCookie(ck) |
| 51 | } |
| 52 | req.Header.Set("Accept", "text/event-stream") |
| 53 | resp, err := srv.Client().Do(req) |
| 54 | if err != nil { |
| 55 | cancel() |
| 56 | c.t.Fatalf("GET %s: %v", target, err) |
| 57 | } |
| 58 | if resp.StatusCode != http.StatusOK { |
| 59 | b, _ := io.ReadAll(resp.Body) |
| 60 | resp.Body.Close() |
| 61 | cancel() |
| 62 | c.t.Fatalf("GET %s: %d\n%s", target, resp.StatusCode, b) |
| 63 | } |
| 64 | if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/event-stream") { |
| 65 | resp.Body.Close() |
| 66 | cancel() |
| 67 | c.t.Fatalf("GET %s: Content-Type %q", target, ct) |
| 68 | } |
| 69 | s := &sseReader{ |
| 70 | t: c.t, cancel: cancel, body: resp.Body, |
| 71 | events: make(chan sseEvent, 64), hb: make(chan struct{}, 64), |
| 72 | done: make(chan struct{}), closing: make(chan struct{}), |
| 73 | } |
| 74 | c.t.Cleanup(s.close) |
| 75 | go s.read() |
| 76 | return s |
| 77 | } |
| 78 | |
| 79 | // read parses the wire format the way an EventSource does: a field is |
| 80 | // "name:" with one optional space after the colon, several data lines |
| 81 | // join with a newline, a line starting with a colon is a comment, and a |
| 82 | // blank line dispatches what has been collected. |
| 83 | func (s *sseReader) read() { |
| 84 | defer close(s.done) |
| 85 | sc := bufio.NewScanner(s.body) |
| 86 | sc.Buffer(make([]byte, 0, 64*1024), 1<<20) |
| 87 | var ev sseEvent |
| 88 | var hasData bool |
| 89 | for sc.Scan() { |
| 90 | line := sc.Text() |
| 91 | switch { |
| 92 | case line == "": |
| 93 | if ev.name != "" || hasData { |
| 94 | s.dispatch(ev) |
| 95 | } |
| 96 | ev, hasData = sseEvent{}, false |
| 97 | case strings.HasPrefix(line, ":"): |
| 98 | select { |
| 99 | case s.hb <- struct{}{}: |
| 100 | default: |
| 101 | } |
| 102 | case strings.HasPrefix(line, "event:"): |
| 103 | ev.name = field(line, "event:") |
| 104 | case strings.HasPrefix(line, "data:"): |
| 105 | if hasData { |
| 106 | ev.data = append(ev.data, '\n') |
| 107 | } |
| 108 | ev.data = append(ev.data, field(line, "data:")...) |
| 109 | hasData = true |
| 110 | } |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | func field(line, name string) string { |
| 115 | return strings.TrimPrefix(strings.TrimPrefix(line, name), " ") |
| 116 | } |
| 117 | |
| 118 | // dispatch hands one event to the test goroutine. It blocks rather than |
| 119 | // dropping: an overflowing buffer means a test is not reading what it |
| 120 | // asked for, and that should fail out loud rather than quietly lose the |
| 121 | // event that would have failed the assertion. |
| 122 | func (s *sseReader) dispatch(ev sseEvent) { |
| 123 | select { |
| 124 | case s.events <- ev: |
| 125 | case <-s.closing: |
| 126 | case <-time.After(5 * time.Second): |
| 127 | s.t.Errorf("sse: nothing read %q for five seconds; the event buffer overflowed", ev.name) |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | // next waits for one event. |
| 132 | func (s *sseReader) next(timeout time.Duration) (string, []byte, bool) { |
| 133 | select { |
| 134 | case ev := <-s.events: |
| 135 | return ev.name, ev.data, true |
| 136 | case <-time.After(timeout): |
| 137 | return "", nil, false |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | // hello reads the first event, which is always hello (spec §4.1), and |
| 142 | // returns the peer id and the boot id it carries. |
| 143 | func (s *sseReader) hello() (peer, boot string) { |
| 144 | s.t.Helper() |
| 145 | name, data, ok := s.next(2 * time.Second) |
| 146 | if !ok || name != "hello" { |
| 147 | s.t.Fatalf("first event is %q (ok=%v), want hello", name, ok) |
| 148 | } |
| 149 | var body struct{ Peer, Boot string } |
| 150 | if err := json.Unmarshal(data, &body); err != nil { |
| 151 | s.t.Fatalf("hello %s: %v", data, err) |
| 152 | } |
| 153 | return body.Peer, body.Boot |
| 154 | } |
| 155 | |
| 156 | // nextOf skips events until the named one arrives, or the timeout |
| 157 | // passes — for a test that expects some event (a roster, a peer) ahead |
| 158 | // of the one it actually wants to assert on. |
| 159 | func (s *sseReader) nextOf(event string, timeout time.Duration) (string, []byte, bool) { |
| 160 | s.t.Helper() |
| 161 | deadline := time.After(timeout) |
| 162 | for { |
| 163 | select { |
| 164 | case ev := <-s.events: |
| 165 | if ev.name == event { |
| 166 | return ev.name, ev.data, true |
| 167 | } |
| 168 | case <-deadline: |
| 169 | return "", nil, false |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | // waitHeartbeat waits for one SSE comment line, which is the only thing |
| 175 | // the server sends on an idle stream. |
| 176 | func (s *sseReader) waitHeartbeat(timeout time.Duration) bool { |
| 177 | select { |
| 178 | case <-s.hb: |
| 179 | return true |
| 180 | case <-time.After(timeout): |
| 181 | return false |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | // waitClosed waits for the server to end the stream. |
| 186 | func (s *sseReader) waitClosed(timeout time.Duration) bool { |
| 187 | select { |
| 188 | case <-s.done: |
| 189 | return true |
| 190 | case <-time.After(timeout): |
| 191 | return false |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | // close is what a browser navigating away does. It waits for the read |
| 196 | // goroutine to finish so the test never races the server's own exit. |
| 197 | func (s *sseReader) close() { |
| 198 | s.once.Do(func() { |
| 199 | close(s.closing) |
| 200 | s.cancel() |
| 201 | s.body.Close() |
| 202 | select { |
| 203 | case <-s.done: |
| 204 | case <-time.After(2 * time.Second): |
| 205 | s.t.Error("the stream reader did not stop") |
| 206 | } |
| 207 | }) |
| 208 | } |
| 209 | |
| 210 | // rawStream is the stream with nobody draining it in the background — |
| 211 | // the one thing sseReader cannot be, because its read goroutine is |
| 212 | // always reading. A test that wants the server's own 64-event |
| 213 | // subscriber buffer to overflow (spec §4.4) has to stop reading the |
| 214 | // socket: that is what backs the handler's write up, and only a handler |
| 215 | // that is not draining lets the buffer behind it fill. |
| 216 | // |
| 217 | // Nothing here parses more of the wire format than the tests need: an |
| 218 | // event name, its data, and heartbeat comments skipped. |
| 219 | type rawStream struct { |
| 220 | t *testing.T |
| 221 | cancel context.CancelFunc |
| 222 | body io.ReadCloser |
| 223 | r *bufio.Reader |
| 224 | once sync.Once |
| 225 | } |
| 226 | |
| 227 | // tinyWindowClient dials with a deliberately small receive buffer. It is |
| 228 | // what makes "the client stopped reading" mean something: with the |
| 229 | // kernel's own defaults, loopback will happily absorb megabytes on the |
| 230 | // reader's behalf, and the server's write never blocks, so the hub's |
| 231 | // buffer never fills and the test proves nothing. SO_RCVBUF also turns |
| 232 | // receive-window autotuning off, which is the point — the window must |
| 233 | // stay small rather than growing to meet the flood. |
| 234 | func tinyWindowClient() *http.Client { |
| 235 | d := &net.Dialer{ |
| 236 | Control: func(network, address string, c syscall.RawConn) error { |
| 237 | var setErr error |
| 238 | if err := c.Control(func(fd uintptr) { |
| 239 | setErr = syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_RCVBUF, 4096) |
| 240 | }); err != nil { |
| 241 | return err |
| 242 | } |
| 243 | return setErr |
| 244 | }, |
| 245 | } |
| 246 | return &http.Client{Transport: &http.Transport{DialContext: d.DialContext}} |
| 247 | } |
| 248 | |
| 249 | func (c *client) rawStream(target string) *rawStream { |
| 250 | c.t.Helper() |
| 251 | srv := c.x.server() |
| 252 | ctx, cancel := context.WithCancel(context.Background()) |
| 253 | req, err := http.NewRequestWithContext(ctx, http.MethodGet, srv.URL+target, nil) |
| 254 | if err != nil { |
| 255 | cancel() |
| 256 | c.t.Fatal(err) |
| 257 | } |
| 258 | for _, ck := range c.cookies { |
| 259 | req.AddCookie(ck) |
| 260 | } |
| 261 | req.Header.Set("Accept", "text/event-stream") |
| 262 | resp, err := tinyWindowClient().Do(req) |
| 263 | if err != nil { |
| 264 | cancel() |
| 265 | c.t.Fatalf("GET %s: %v", target, err) |
| 266 | } |
| 267 | if resp.StatusCode != http.StatusOK { |
| 268 | b, _ := io.ReadAll(resp.Body) |
| 269 | resp.Body.Close() |
| 270 | cancel() |
| 271 | c.t.Fatalf("GET %s: %d\n%s", target, resp.StatusCode, b) |
| 272 | } |
| 273 | // A small reader on purpose: the socket must stop being drained the |
| 274 | // moment the test stops calling next, not a buffer's worth later. |
| 275 | s := &rawStream{t: c.t, cancel: cancel, body: resp.Body, r: bufio.NewReaderSize(resp.Body, 512)} |
| 276 | c.t.Cleanup(s.close) |
| 277 | return s |
| 278 | } |
| 279 | |
| 280 | // next reads one event, blocking until the server sends one or the |
| 281 | // timeout cancels the request out from under the read. |
| 282 | func (s *rawStream) next(timeout time.Duration) (string, []byte, bool) { |
| 283 | s.t.Helper() |
| 284 | stop := time.AfterFunc(timeout, s.cancel) |
| 285 | defer stop.Stop() |
| 286 | var name string |
| 287 | var data []byte |
| 288 | for { |
| 289 | raw, err := s.r.ReadString('\n') |
| 290 | if err != nil { |
| 291 | return "", nil, false |
| 292 | } |
| 293 | line := strings.TrimRight(raw, "\r\n") |
| 294 | switch { |
| 295 | case line == "": |
| 296 | if name != "" || data != nil { |
| 297 | return name, data, true |
| 298 | } |
| 299 | case strings.HasPrefix(line, ":"): // heartbeat |
| 300 | case strings.HasPrefix(line, "event:"): |
| 301 | name = field(line, "event:") |
| 302 | case strings.HasPrefix(line, "data:"): |
| 303 | data = append(data, field(line, "data:")...) |
| 304 | } |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | // hello is next's first event, which is always hello (§4.1). |
| 309 | func (s *rawStream) hello() string { |
| 310 | s.t.Helper() |
| 311 | name, data, ok := s.next(2 * time.Second) |
| 312 | if !ok || name != "hello" { |
| 313 | s.t.Fatalf("first event is %q (ok=%v), want hello", name, ok) |
| 314 | } |
| 315 | var body struct{ Peer string } |
| 316 | if err := json.Unmarshal(data, &body); err != nil { |
| 317 | s.t.Fatalf("hello %s: %v", data, err) |
| 318 | } |
| 319 | return body.Peer |
| 320 | } |
| 321 | |
| 322 | func (s *rawStream) close() { |
| 323 | s.once.Do(func() { |
| 324 | s.cancel() |
| 325 | s.body.Close() |
| 326 | }) |
| 327 | } |
| 328 | |
| 329 | // signal is POST /m/{sqid}/signal, the upstream half of §4.1: a JSON |
| 330 | // body carrying the peer and the message, under CSRF. body is decoded |
| 331 | // into a map and given "peer", rather than spliced in as a string — a |
| 332 | // caller's body of "{}" or "" is not a special case this way, and every |
| 333 | // call sends one well-formed JSON document. The endpoint itself arrives |
| 334 | // with the signal handler; this is the client for it. |
| 335 | func (c *client) signal(sqid, peer, body string) (*http.Response, []byte) { |
| 336 | c.t.Helper() |
| 337 | msg := map[string]any{} |
| 338 | if strings.TrimSpace(body) != "" { |
| 339 | if err := json.Unmarshal([]byte(body), &msg); err != nil { |
| 340 | c.t.Fatalf("signal body %q: %v", body, err) |
| 341 | } |
| 342 | } |
| 343 | msg["peer"] = peer |
| 344 | payload, err := json.Marshal(msg) |
| 345 | if err != nil { |
| 346 | c.t.Fatal(err) |
| 347 | } |
| 348 | ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) |
| 349 | defer cancel() |
| 350 | req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.x.server().URL+"/m/"+sqid+"/signal", bytes.NewReader(payload)) |
| 351 | if err != nil { |
| 352 | c.t.Fatal(err) |
| 353 | } |
| 354 | for _, ck := range c.cookies { |
| 355 | req.AddCookie(ck) |
| 356 | } |
| 357 | req.Header.Set("Content-Type", "application/json") |
| 358 | req.Header.Set("Origin", testOrigin) |
| 359 | resp, err := c.x.server().Client().Do(req) |
| 360 | if err != nil { |
| 361 | c.t.Fatalf("POST signal: %v", err) |
| 362 | } |
| 363 | b, err := io.ReadAll(resp.Body) |
| 364 | resp.Body.Close() |
| 365 | if err != nil { |
| 366 | c.t.Fatalf("POST signal: reading body: %v", err) |
| 367 | } |
| 368 | return resp, b |
| 369 | } |
| 370 | |
| 371 | // signalRaw posts body verbatim, unlike signal, which always injects a |
| 372 | // well-formed "peer" — for the shapes signal cannot express at all: a |
| 373 | // malformed document, or one with no peer field. |
| 374 | func (c *client) signalRaw(sqid, body string) (*http.Response, []byte) { |
| 375 | c.t.Helper() |
| 376 | ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) |
| 377 | defer cancel() |
| 378 | req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.x.server().URL+"/m/"+sqid+"/signal", strings.NewReader(body)) |
| 379 | if err != nil { |
| 380 | c.t.Fatal(err) |
| 381 | } |
| 382 | for _, ck := range c.cookies { |
| 383 | req.AddCookie(ck) |
| 384 | } |
| 385 | req.Header.Set("Content-Type", "application/json") |
| 386 | req.Header.Set("Origin", testOrigin) |
| 387 | resp, err := c.x.server().Client().Do(req) |
| 388 | if err != nil { |
| 389 | c.t.Fatalf("POST signal: %v", err) |
| 390 | } |
| 391 | b, err := io.ReadAll(resp.Body) |
| 392 | resp.Body.Close() |
| 393 | if err != nil { |
| 394 | c.t.Fatalf("POST signal: reading body: %v", err) |
| 395 | } |
| 396 | return resp, b |
| 397 | } |
| 398 | |
amadan