| 1 | package extension |
| 2 | |
| 3 | import ( |
| 4 | "bufio" |
| 5 | "context" |
| 6 | "encoding/json" |
| 7 | "errors" |
| 8 | "io" |
| 9 | "log" |
| 10 | "sync" |
| 11 | "testing" |
| 12 | "time" |
| 13 | ) |
| 14 | |
| 15 | // fakeHost is a scriptable in-memory Reasonix host speaking raw JSON-RPC |
| 16 | // over two io.Pipes: it writes Host → Extension frames into the SDK's stdin |
| 17 | // pipe and reads the SDK's stdout pipe, answering Extension → Host requests |
| 18 | // with scripted handlers. |
| 19 | type fakeHost struct { |
| 20 | t *testing.T |
| 21 | |
| 22 | toSDK *io.PipeWriter // host writes, SDK reads |
| 23 | fromSDK *io.PipeReader // SDK writes, host reads |
| 24 | |
| 25 | writeMu sync.Mutex |
| 26 | nextID int64 |
| 27 | |
| 28 | pendingMu sync.Mutex |
| 29 | pending map[int64]chan hostResponse |
| 30 | |
| 31 | strayMu sync.Mutex |
| 32 | strays []strayResponse |
| 33 | handlersMu sync.Mutex |
| 34 | handlers map[string]func(params json.RawMessage) (any, *hostError) |
| 35 | requestLog map[string][]json.RawMessage |
| 36 | |
| 37 | notesMu sync.Mutex |
| 38 | notifications []hostNotification |
| 39 | |
| 40 | readerDone chan struct{} |
| 41 | } |
| 42 | |
| 43 | type hostError struct { |
| 44 | Code int |
| 45 | Message string |
| 46 | Data any |
| 47 | } |
| 48 | |
| 49 | type hostResponse struct { |
| 50 | Result json.RawMessage |
| 51 | Err *hostError |
| 52 | } |
| 53 | |
| 54 | // strayResponse is an SDK response with no matching pending host request — |
| 55 | // typically a -32600 rejection of a malformed raw frame. |
| 56 | type strayResponse struct { |
| 57 | ID json.RawMessage |
| 58 | Error *hostError |
| 59 | } |
| 60 | |
| 61 | type hostNotification struct { |
| 62 | Method string |
| 63 | Params json.RawMessage |
| 64 | } |
| 65 | |
| 66 | type hostFrame struct { |
| 67 | JSONRPC string `json:"jsonrpc"` |
| 68 | ID json.RawMessage `json:"id"` |
| 69 | Method string `json:"method"` |
| 70 | Params json.RawMessage `json:"params"` |
| 71 | Result json.RawMessage `json:"result"` |
| 72 | Error *hostErrorFrame `json:"error"` |
| 73 | } |
| 74 | |
| 75 | type hostErrorFrame struct { |
| 76 | Code int `json:"code"` |
| 77 | Message string `json:"message"` |
| 78 | Data json.RawMessage `json:"data,omitempty"` |
| 79 | } |
| 80 | |
| 81 | // serveWaiter caches Serve's result so both the test and its cleanup can |
| 82 | // observe it exactly once. |
| 83 | type serveWaiter struct { |
| 84 | ch chan error |
| 85 | mu sync.Mutex |
| 86 | err error |
| 87 | received bool |
| 88 | } |
| 89 | |
| 90 | // wait blocks up to timeout for Serve's result; later calls return the |
| 91 | // cached value. ok is false on timeout. |
| 92 | func (w *serveWaiter) wait(timeout time.Duration) (err error, ok bool) { |
| 93 | w.mu.Lock() |
| 94 | if w.received { |
| 95 | w.mu.Unlock() |
| 96 | return w.err, true |
| 97 | } |
| 98 | w.mu.Unlock() |
| 99 | select { |
| 100 | case err := <-w.ch: |
| 101 | w.mu.Lock() |
| 102 | w.err = err |
| 103 | w.received = true |
| 104 | w.mu.Unlock() |
| 105 | return err, true |
| 106 | case <-time.After(timeout): |
| 107 | return nil, false |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | // startFakeHost launches Serve against a fake host and returns both. The |
| 112 | // host's read loop answers SDK requests until cleanup. |
| 113 | func startFakeHost(t *testing.T, h Handler, opts Options) (*fakeHost, *serveWaiter) { |
| 114 | t.Helper() |
| 115 | sdkStdinR, sdkStdinW := io.Pipe() |
| 116 | sdkStdoutR, sdkStdoutW := io.Pipe() |
| 117 | opts.Stdin = sdkStdinR |
| 118 | opts.Stdout = sdkStdoutW |
| 119 | if opts.Logger == nil { |
| 120 | opts.Logger = log.New(io.Discard, "", 0) |
| 121 | } |
| 122 | waiter := &serveWaiter{ch: make(chan error, 1)} |
| 123 | go func() { waiter.ch <- Serve(context.Background(), h, opts) }() |
| 124 | host := &fakeHost{ |
| 125 | t: t, |
| 126 | toSDK: sdkStdinW, |
| 127 | fromSDK: sdkStdoutR, |
| 128 | pending: make(map[int64]chan hostResponse), |
| 129 | handlers: make(map[string]func(json.RawMessage) (any, *hostError)), |
| 130 | requestLog: make(map[string][]json.RawMessage), |
| 131 | readerDone: make(chan struct{}), |
| 132 | } |
| 133 | go host.readLoop() |
| 134 | t.Cleanup(func() { |
| 135 | _ = host.toSDK.Close() |
| 136 | _ = host.fromSDK.Close() |
| 137 | <-host.readerDone |
| 138 | if _, ok := waiter.wait(5 * time.Second); !ok { |
| 139 | t.Errorf("Serve did not return after the transport closed") |
| 140 | } |
| 141 | }) |
| 142 | return host, waiter |
| 143 | } |
| 144 | |
| 145 | // readLoop consumes every frame the SDK writes: responses resolve pending |
| 146 | // host requests, requests are routed to scripted handlers, notifications are |
| 147 | // recorded. |
| 148 | func (h *fakeHost) readLoop() { |
| 149 | defer close(h.readerDone) |
| 150 | scanner := bufio.NewScanner(h.fromSDK) |
| 151 | scanner.Buffer(make([]byte, 0, 64<<10), FrameBytes*2) |
| 152 | for scanner.Scan() { |
| 153 | line := scanner.Bytes() |
| 154 | var frame hostFrame |
| 155 | if err := json.Unmarshal(line, &frame); err != nil { |
| 156 | h.t.Errorf("fake host: undecodable SDK frame %q: %v", line, err) |
| 157 | continue |
| 158 | } |
| 159 | switch { |
| 160 | case frame.Method != "" && len(frame.ID) > 0: |
| 161 | h.serveSDKRequest(frame) |
| 162 | case frame.Method != "": |
| 163 | h.notesMu.Lock() |
| 164 | h.notifications = append(h.notifications, hostNotification{Method: frame.Method, Params: frame.Params}) |
| 165 | h.notesMu.Unlock() |
| 166 | case len(frame.ID) > 0: |
| 167 | resp := hostResponse{Result: frame.Result} |
| 168 | if frame.Error != nil { |
| 169 | resp.Err = &hostError{Code: frame.Error.Code, Message: frame.Error.Message} |
| 170 | if len(frame.Error.Data) > 0 { |
| 171 | var data ProtocolErrorData |
| 172 | if err := json.Unmarshal(frame.Error.Data, &data); err == nil { |
| 173 | resp.Err.Data = data |
| 174 | } |
| 175 | } |
| 176 | } |
| 177 | var id int64 |
| 178 | if err := json.Unmarshal(frame.ID, &id); err != nil { |
| 179 | h.recordStray(frame.ID, resp.Err) |
| 180 | continue |
| 181 | } |
| 182 | h.pendingMu.Lock() |
| 183 | ch := h.pending[id] |
| 184 | delete(h.pending, id) |
| 185 | h.pendingMu.Unlock() |
| 186 | if ch == nil { |
| 187 | h.recordStray(frame.ID, resp.Err) |
| 188 | continue |
| 189 | } |
| 190 | ch <- resp |
| 191 | } |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | func (h *fakeHost) recordStray(id json.RawMessage, herr *hostError) { |
| 196 | h.strayMu.Lock() |
| 197 | defer h.strayMu.Unlock() |
| 198 | h.strays = append(h.strays, strayResponse{ID: append(json.RawMessage(nil), id...), Error: herr}) |
| 199 | } |
| 200 | |
| 201 | // nextStray waits for one stray error response and returns it. |
| 202 | func (h *fakeHost) nextStray() strayResponse { |
| 203 | deadline := time.Now().Add(5 * time.Second) |
| 204 | for time.Now().Before(deadline) { |
| 205 | h.strayMu.Lock() |
| 206 | if len(h.strays) > 0 { |
| 207 | stray := h.strays[0] |
| 208 | h.strays = h.strays[1:] |
| 209 | h.strayMu.Unlock() |
| 210 | return stray |
| 211 | } |
| 212 | h.strayMu.Unlock() |
| 213 | time.Sleep(5 * time.Millisecond) |
| 214 | } |
| 215 | h.t.Fatalf("fake host: no stray response within 5s") |
| 216 | return strayResponse{} |
| 217 | } |
| 218 | |
| 219 | func (h *fakeHost) serveSDKRequest(frame hostFrame) { |
| 220 | h.handlersMu.Lock() |
| 221 | handler := h.handlers[frame.Method] |
| 222 | h.requestLog[frame.Method] = append(h.requestLog[frame.Method], append(json.RawMessage(nil), frame.Params...)) |
| 223 | h.handlersMu.Unlock() |
| 224 | var result any |
| 225 | var herr *hostError |
| 226 | if handler == nil { |
| 227 | herr = &hostError{Code: CodeMethodNotFound, Message: "method not found: " + frame.Method} |
| 228 | } else { |
| 229 | result, herr = handler(frame.Params) |
| 230 | } |
| 231 | var out []byte |
| 232 | if herr != nil { |
| 233 | errorFrame := map[string]any{"code": herr.Code, "message": herr.Message} |
| 234 | if herr.Data != nil { |
| 235 | errorFrame["data"] = herr.Data |
| 236 | } |
| 237 | out, _ = json.Marshal(map[string]any{"jsonrpc": "2.0", "id": json.RawMessage(frame.ID), "error": errorFrame}) |
| 238 | } else { |
| 239 | raw, _ := json.Marshal(result) |
| 240 | out, _ = json.Marshal(map[string]any{"jsonrpc": "2.0", "id": json.RawMessage(frame.ID), "result": json.RawMessage(raw)}) |
| 241 | } |
| 242 | h.writeLine(out) |
| 243 | } |
| 244 | |
| 245 | // onRequest installs the scripted answerer for one Extension → Host method. |
| 246 | func (h *fakeHost) onRequest(method string, handler func(params json.RawMessage) (any, *hostError)) { |
| 247 | h.handlersMu.Lock() |
| 248 | defer h.handlersMu.Unlock() |
| 249 | h.handlers[method] = handler |
| 250 | } |
| 251 | |
| 252 | // lastRawParams returns the raw params of the most recent Extension → Host |
| 253 | // request for method. |
| 254 | func (h *fakeHost) lastRawParams(t *testing.T, method string) json.RawMessage { |
| 255 | t.Helper() |
| 256 | h.handlersMu.Lock() |
| 257 | defer h.handlersMu.Unlock() |
| 258 | log := h.requestLog[method] |
| 259 | if len(log) == 0 { |
| 260 | t.Fatalf("fake host: no %s request recorded", method) |
| 261 | } |
| 262 | return log[len(log)-1] |
| 263 | } |
| 264 | |
| 265 | // request sends one Host → Extension request and waits for its response. |
| 266 | func (h *fakeHost) request(method string, params any) hostResponse { |
| 267 | _, ch := h.startRequest(method, params) |
| 268 | select { |
| 269 | case resp := <-ch: |
| 270 | return resp |
| 271 | case <-time.After(10 * time.Second): |
| 272 | h.t.Fatalf("fake host: no response to %s", method) |
| 273 | return hostResponse{} |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | // startRequest sends one Host → Extension request without waiting; the |
| 278 | // response arrives on the returned channel. |
| 279 | func (h *fakeHost) startRequest(method string, params any) (int64, chan hostResponse) { |
| 280 | h.pendingMu.Lock() |
| 281 | h.nextID++ |
| 282 | id := h.nextID |
| 283 | ch := make(chan hostResponse, 1) |
| 284 | h.pending[id] = ch |
| 285 | h.pendingMu.Unlock() |
| 286 | raw, _ := json.Marshal(params) |
| 287 | frame, _ := json.Marshal(map[string]any{ |
| 288 | "jsonrpc": "2.0", "id": id, "method": method, "params": json.RawMessage(raw), |
| 289 | }) |
| 290 | h.writeLine(frame) |
| 291 | return id, ch |
| 292 | } |
| 293 | |
| 294 | // notify sends one Host → Extension notification. |
| 295 | func (h *fakeHost) notify(method string, params any) { |
| 296 | raw, _ := json.Marshal(params) |
| 297 | frame, _ := json.Marshal(map[string]any{"jsonrpc": "2.0", "method": method, "params": json.RawMessage(raw)}) |
| 298 | h.writeLine(frame) |
| 299 | } |
| 300 | |
| 301 | // writeRaw sends one unvalidated frame, for strict-frame violation tests. |
| 302 | func (h *fakeHost) writeRaw(frame []byte) { h.writeLine(frame) } |
| 303 | |
| 304 | func (h *fakeHost) writeLine(frame []byte) { |
| 305 | h.writeMu.Lock() |
| 306 | defer h.writeMu.Unlock() |
| 307 | if _, err := h.toSDK.Write(append(frame, '\n')); err != nil { |
| 308 | h.t.Errorf("fake host: write to SDK: %v", err) |
| 309 | } |
| 310 | } |
| 311 | |
| 312 | // handshake runs the standard initialize + initialized sequence and returns |
| 313 | // the decoded initialize result. |
| 314 | func (h *fakeHost) handshake(t *testing.T) InitializeResult { |
| 315 | t.Helper() |
| 316 | resp := h.request(MethodExtensionInitialize, InitializeParams{ |
| 317 | ProtocolVersion: ProtocolVersion, |
| 318 | ProtocolID: ProtocolID, |
| 319 | Manifest: ManifestExpectation{Intercepts: InterceptEvents(), Capabilities: []string{"providers", "ui"}}, |
| 320 | Session: SessionContext{SessionID: "sess-1", WorkspaceRoot: "/repo", Generation: 7}, |
| 321 | Capabilities: HostCapabilities{ContentRefs: true, UIHost: UIHostHeadless, ProtocolVersion: ProtocolVersion}, |
| 322 | }) |
| 323 | if resp.Err != nil { |
| 324 | t.Fatalf("initialize failed: %+v", resp.Err) |
| 325 | } |
| 326 | var result InitializeResult |
| 327 | if err := json.Unmarshal(resp.Result, &result); err != nil { |
| 328 | t.Fatalf("decode initialize result: %v", err) |
| 329 | } |
| 330 | h.notify(MethodExtensionInitialized, InitializedParams{}) |
| 331 | return result |
| 332 | } |
| 333 | |
| 334 | // nextNotification waits for one SDK notification with the given method. |
| 335 | func (h *fakeHost) nextNotification(method string) hostNotification { |
| 336 | deadline := time.Now().Add(5 * time.Second) |
| 337 | for time.Now().Before(deadline) { |
| 338 | h.notesMu.Lock() |
| 339 | for i, note := range h.notifications { |
| 340 | if note.Method == method { |
| 341 | h.notifications = append(h.notifications[:i], h.notifications[i+1:]...) |
| 342 | h.notesMu.Unlock() |
| 343 | return note |
| 344 | } |
| 345 | } |
| 346 | h.notesMu.Unlock() |
| 347 | time.Sleep(5 * time.Millisecond) |
| 348 | } |
| 349 | h.t.Fatalf("fake host: no %s notification within 5s", method) |
| 350 | return hostNotification{} |
| 351 | } |
| 352 | |
| 353 | // notificationsSnapshot returns all recorded SDK notifications. |
| 354 | func (h *fakeHost) notificationsSnapshot() []hostNotification { |
| 355 | h.notesMu.Lock() |
| 356 | defer h.notesMu.Unlock() |
| 357 | return append([]hostNotification(nil), h.notifications...) |
| 358 | } |
| 359 | |
| 360 | // streamNotifications returns all stream/chunk and stream/end notifications |
| 361 | // recorded so far, in arrival order, decoded. |
| 362 | func (h *fakeHost) streamNotifications() (chunks []StreamChunkParams, ends []StreamEndParams) { |
| 363 | for _, note := range h.notificationsSnapshot() { |
| 364 | switch note.Method { |
| 365 | case MethodExtensionProviderStreamChunk: |
| 366 | var p StreamChunkParams |
| 367 | if err := json.Unmarshal(note.Params, &p); err == nil { |
| 368 | chunks = append(chunks, p) |
| 369 | } |
| 370 | case MethodExtensionProviderStreamEnd: |
| 371 | var p StreamEndParams |
| 372 | if err := json.Unmarshal(note.Params, &p); err == nil { |
| 373 | ends = append(ends, p) |
| 374 | } |
| 375 | } |
| 376 | } |
| 377 | return chunks, ends |
| 378 | } |
| 379 | |
| 380 | // waitStreamEnd polls until one stream/end notification arrives and returns |
| 381 | // it decoded. It does not consume anything. |
| 382 | func (h *fakeHost) waitStreamEnd() StreamEndParams { |
| 383 | deadline := time.Now().Add(5 * time.Second) |
| 384 | for time.Now().Before(deadline) { |
| 385 | _, ends := h.streamNotifications() |
| 386 | if len(ends) > 0 { |
| 387 | return ends[len(ends)-1] |
| 388 | } |
| 389 | time.Sleep(5 * time.Millisecond) |
| 390 | } |
| 391 | h.t.Fatalf("fake host: no stream/end within 5s") |
| 392 | return StreamEndParams{} |
| 393 | } |
| 394 | |
| 395 | // testHandler is a Handler returning a fixed declaration. |
| 396 | type testHandler struct { |
| 397 | result *InitializeResult |
| 398 | err error |
| 399 | seen *InitializeParams |
| 400 | } |
| 401 | |
| 402 | func (h *testHandler) Initialize(_ context.Context, p InitializeParams) (*InitializeResult, error) { |
| 403 | if h.seen != nil { |
| 404 | *h.seen = p |
| 405 | } |
| 406 | if h.err != nil { |
| 407 | return nil, h.err |
| 408 | } |
| 409 | return h.result, nil |
| 410 | } |
| 411 | |
| 412 | // HandlerFunc adapts a function to the Handler interface. |
| 413 | type HandlerFunc func(ctx context.Context, p InitializeParams) (*InitializeResult, error) |
| 414 | |
| 415 | // Initialize implements Handler. |
| 416 | func (f HandlerFunc) Initialize(ctx context.Context, p InitializeParams) (*InitializeResult, error) { |
| 417 | return f(ctx, p) |
| 418 | } |
| 419 | |
| 420 | func basicHandler() *testHandler { |
| 421 | return &testHandler{result: &InitializeResult{ |
| 422 | Name: "test-ext", Version: "0.1.0", |
| 423 | Subscriptions: []string{"tool.before"}, |
| 424 | }} |
| 425 | } |
| 426 | |
| 427 | var errTest = errors.New("test error") |
| 428 |