v1.3.2: add request context and generation-only binding

client_ts_test.go

@@ -167,6 +167,153 @@ result = await requestInterceptorClient.request("Svc", "interceptors", { value:
 assert.deepEqual(requestInterceptorSeen, { value: 1 });
 assert.equal(result.msg, "intercepted");
 
+const stateClient = new Client("http://example.test");
+stateClient.setState({ shared: "global", globalOnly: "yes" });
+const stateContexts = new Map();
+const nativeResponses = new Map();
+const payloads = new Map();
+let releaseFirst;
+const firstMayContinue = new Promise(resolve => { releaseFirst = resolve; });
+let firstInterceptorEntered;
+const firstDidEnter = new Promise(resolve => { firstInterceptorEntered = resolve; });
+let firstStateReference;
+stateClient.addRequestInterceptor(async (_service, method, state, dto) => {
+  state.interceptor = dto.id;
+  if (method === "first") {
+    firstStateReference = state;
+    firstInterceptorEntered();
+    await firstMayContinue;
+  }
+  state.completed = dto.id;
+});
+stateClient.addResponseInterceptor((_service, method, _value, context) => {
+  stateContexts.set(method, context);
+});
+globalThis.fetch = async (_url, init) => {
+  const payload = JSON.parse(init.body);
+  payloads.set(payload.methodName, payload);
+  const response = json({ status: 0, data: payload.methodName });
+  nativeResponses.set(payload.methodName, response);
+  return response;
+};
+const firstOverride = { shared: "first", requestOnly: "one" };
+const firstRequest = stateClient.request("Svc", "first", { id: "one" }, { state: firstOverride });
+await firstDidEnter;
+firstOverride.shared = "mutated outside";
+const secondRequest = stateClient.request("Svc", "second", { id: "two" }, {
+  state: { shared: "second", requestOnly: "two" },
+});
+assert.equal((await secondRequest).status, 0);
+releaseFirst();
+assert.equal((await firstRequest).status, 0);
+assert.deepEqual(payloads.get("first").state, {
+  shared: "first",
+  globalOnly: "yes",
+  requestOnly: "one",
+  interceptor: "one",
+  completed: "one",
+});
+assert.deepEqual(payloads.get("second").state, {
+  shared: "second",
+  globalOnly: "yes",
+  requestOnly: "two",
+  interceptor: "two",
+  completed: "two",
+});
+firstStateReference.shared = "mutated after snapshot";
+for (const method of ["first", "second"]) {
+  const context = stateContexts.get(method);
+  assert.deepEqual(context.requestState, payloads.get(method).state);
+  assert.equal(Object.isFrozen(context.requestState), true);
+  assert.equal(Object.isFrozen(context), true);
+  assert.equal(context.response, nativeResponses.get(method));
+  assert.ok(context.response instanceof Response);
+}
+assert.equal(stateContexts.get("first").requestState.shared, "first");
+
+const throwingState = Object.defineProperty({}, "token", {
+  enumerable: true,
+  get() { throw new Error("state read failed"); },
+});
+const stateFailureClient = new Client("http://example.test");
+let stateFailureSeen = [];
+stateFailureClient.addResponseInterceptor((_service, _method, value, context) => {
+  stateFailureSeen.push([value.status, context.requestState]);
+});
+globalThis.fetch = async () => assert.fail("fetch must not run for state failure");
+result = await stateFailureClient.request("Svc", "requestStateFailure", undefined, { state: throwingState });
+assert.equal(result.status, 1);
+assert.match(result.msg, /prepare request state/i);
+result = await stateFailureClient.stream("Svc", "streamStateFailure", undefined, () => {}, { state: throwingState });
+assert.equal(result.status, 1);
+assert.match(result.msg, /prepare request state/i);
+assert.deepEqual(stateFailureSeen, [[1, {}], [1, {}]]);
+
+const snapshotFailureClient = new Client("http://example.test");
+snapshotFailureClient.addRequestInterceptor((_service, _method, state) => {
+  Object.defineProperty(state, "broken", {
+    enumerable: true,
+    get() { throw new Error("snapshot read failed"); },
+  });
+});
+globalThis.fetch = async () => assert.fail("fetch must not run for snapshot failure");
+result = await snapshotFailureClient.request("Svc", "requestSnapshotFailure");
+assert.equal(result.status, 1);
+assert.match(result.msg, /snapshot request state/i);
+result = await snapshotFailureClient.stream("Svc", "streamSnapshotFailure", undefined, () => {});
+assert.equal(result.status, 1);
+assert.match(result.msg, /snapshot request state/i);
+
+const contextClient = new Client("http://example.test");
+contextClient.setState({ base: "global" });
+const outcomeContexts = new Map();
+contextClient.addResponseInterceptor((_service, method, _value, context) => {
+  outcomeContexts.set(method, context);
+});
+contextClient.addRequestInterceptor((_service, method, state) => {
+  state.method = method;
+  if (method === "requestHookFailure") throw new Error("request context hook");
+});
+globalThis.fetch = async () => assert.fail("fetch must not run before serialization");
+const contextCyclic = {};
+contextCyclic.self = contextCyclic;
+result = await contextClient.request("Svc", "serializeContext", contextCyclic, { state: { base: "request" } });
+assert.equal(result.status, 1);
+assert.deepEqual(outcomeContexts.get("serializeContext").requestState, {
+  base: "request",
+  method: "serializeContext",
+});
+assert.equal(outcomeContexts.get("serializeContext").response, undefined);
+result = await contextClient.request("Svc", "requestHookFailure", undefined, { state: { request: "hook" } });
+assert.equal(result.status, 1);
+assert.deepEqual(outcomeContexts.get("requestHookFailure").requestState, {
+  base: "global",
+  request: "hook",
+  method: "requestHookFailure",
+});
+assert.equal(outcomeContexts.get("requestHookFailure").response, undefined);
+globalThis.fetch = async () => { throw new TypeError("offline"); };
+result = await contextClient.request("Svc", "networkContext", undefined, { state: { request: "network" } });
+assert.equal(result.status, 4);
+assert.deepEqual(outcomeContexts.get("networkContext").requestState, {
+  base: "global",
+  request: "network",
+  method: "networkContext",
+});
+assert.equal(outcomeContexts.get("networkContext").response, undefined);
+const bodyReadResponse = new Response(new ReadableStream({
+  pull(controller) { controller.error(new Error("context body read failed")); },
+}));
+globalThis.fetch = async () => bodyReadResponse;
+result = await contextClient.request("Svc", "bodyReadContext", undefined, { state: { request: "body" } });
+assert.equal(result.status, 4);
+assert.deepEqual(outcomeContexts.get("bodyReadContext").requestState, {
+  base: "global",
+  request: "body",
+  method: "bodyReadContext",
+});
+assert.equal(outcomeContexts.get("bodyReadContext").response, bodyReadResponse);
+
 const failingRequestInterceptor = new Client("http://example.test");
 let normalized = [];
 failingRequestInterceptor.addRequestInterceptor(() => { throw new Error("request hook"); });
@@ -299,6 +446,81 @@ streamHookClient.addResponseInterceptor((_s, _m, value) => { normalized.push(val
 result = await streamHookClient.stream("Svc", "hook", undefined, () => {});
 assert.equal(result.status, 1);
 assert.deepEqual(normalized, [1]);
+
+const streamStateClient = new Client("http://example.test");
+streamStateClient.setState({ shared: "global", globalOnly: "stream" });
+const streamContexts = new Map();
+const streamResponses = new Map();
+const streamPayloads = new Map();
+streamStateClient.addRequestInterceptor((_service, method, state) => {
+  state.interceptor = method;
+  if (method === "streamHookFailure") throw new Error("stream context hook");
+});
+streamStateClient.addResponseInterceptor((_service, method, _value, context) => {
+  streamContexts.set(method, context);
+});
+globalThis.fetch = async (_url, init) => {
+  const payload = JSON.parse(init.body);
+  streamPayloads.set(payload.methodName, payload);
+  if (payload.methodName === "streamNetwork") throw new TypeError("stream offline");
+  const response = payload.methodName === "streamWrongMedia"
+    ? json({ status: 0 })
+    : payload.methodName === "streamReadFailure"
+      ? new Response(new ReadableStream({
+          pull(controller) { controller.error(new Error("stream context read failed")); },
+        }), { headers: { "Content-Type": "application/x-ndjson" } })
+      : ndjson('{"n":1}\n');
+  streamResponses.set(payload.methodName, response);
+  return response;
+};
+result = await streamStateClient.stream("Svc", "streamSuccess", undefined, () => {}, {
+  state: { shared: "request", requestOnly: "success" },
+});
+assert.equal(result.status, 0);
+result = await streamStateClient.stream("Svc", "streamWrongMedia", undefined, () => {}, {
+  state: { shared: "wrong-media" },
+});
+assert.equal(result.status, 1);
+result = await streamStateClient.stream("Svc", "streamNetwork", undefined, () => {}, {
+  state: { shared: "network" },
+});
+assert.equal(result.status, 4);
+result = await streamStateClient.stream("Svc", "streamReadFailure", undefined, () => {}, {
+  state: { shared: "read" },
+});
+assert.equal(result.status, 4);
+const streamCyclic = {};
+streamCyclic.self = streamCyclic;
+result = await streamStateClient.stream("Svc", "streamSerialize", streamCyclic, () => {}, {
+  state: { shared: "serialize" },
+});
+assert.equal(result.status, 1);
+result = await streamStateClient.stream("Svc", "streamHookFailure", undefined, () => {}, {
+  state: { shared: "hook" },
+});
+assert.equal(result.status, 1);
+for (const method of ["streamSuccess", "streamWrongMedia", "streamNetwork", "streamReadFailure"]) {
+  const context = streamContexts.get(method);
+  assert.deepEqual(context.requestState, streamPayloads.get(method).state);
+  assert.equal(Object.isFrozen(context.requestState), true);
+  assert.equal(Object.isFrozen(context), true);
+}
+assert.equal(streamContexts.get("streamSuccess").response, streamResponses.get("streamSuccess"));
+assert.equal(streamContexts.get("streamWrongMedia").response, streamResponses.get("streamWrongMedia"));
+assert.equal(streamContexts.get("streamReadFailure").response, streamResponses.get("streamReadFailure"));
+assert.equal(streamContexts.get("streamNetwork").response, undefined);
+assert.deepEqual(streamContexts.get("streamSerialize").requestState, {
+  shared: "serialize",
+  globalOnly: "stream",
+  interceptor: "streamSerialize",
+});
+assert.equal(streamContexts.get("streamSerialize").response, undefined);
+assert.deepEqual(streamContexts.get("streamHookFailure").requestState, {
+  shared: "hook",
+  globalOnly: "stream",
+  interceptor: "streamHookFailure",
+});
+assert.equal(streamContexts.get("streamHookFailure").response, undefined);
 `
 	scriptPath := filepath.Join(dir, "behavior.mjs")
 	if err := os.WriteFile(scriptPath, []byte(script), 0o644); err != nil {
@@ -320,8 +542,35 @@ func TestTypeScriptClientStrictTypecheck(t *testing.T) {
 	if err := os.WriteFile(path, []byte(templateTs{}.genClientTemplate()), 0o644); err != nil {
 		t.Fatal(err)
 	}
+	usagePath := filepath.Join(dir, "usage.ts")
+	const usage = `import { Client, type ContextResponseInterceptor, type RequestOptions, type ResponseContext, type ResponseInterceptor, type StreamOptions } from "./client";
+
+const requestOptions: RequestOptions = { state: { token: "request" } };
+const streamOptions: StreamOptions = { state: { token: "stream" } };
+const legacy: ResponseInterceptor = (_service, _method, result) => result;
+const legacyConsumer: (service: string, method: string, result: import("./client").result<any>) => unknown = legacy;
+const current: ContextResponseInterceptor = (_service, _method, result, context) => {
+  const token: string | undefined = context.requestState.token;
+  const response: Response | undefined = context.response;
+  void token;
+  void response;
+  return result;
+};
+void legacyConsumer;
+const context = {} as ResponseContext;
+// @ts-expect-error requestState is readonly
+context.requestState.token = "changed";
+const client = new Client("/");
+client.addResponseInterceptor(legacy);
+client.addResponseInterceptor(current);
+void client.request("Svc", "method", undefined, requestOptions);
+void client.stream("Svc", "method", undefined, () => {}, streamOptions);
+`
+	if err := os.WriteFile(usagePath, []byte(usage), 0o644); err != nil {
+		t.Fatal(err)
+	}
 	command := exec.Command(tsc,
-		"--strict", "--noEmit", "--target", "ES2022", "--module", "ESNext", "--lib", "ES2022,DOM", path)
+		"--strict", "--noEmit", "--target", "ES2022", "--module", "ESNext", "--lib", "ES2022,DOM", path, usagePath)
 	if output, err := command.CombinedOutput(); err != nil {
 		t.Fatalf("strict TypeScript check failed: %v\n%s", err, output)
 	}

fun.go

@@ -12,9 +12,9 @@ type Fun struct {
 	methods        map[string]methodInfo
 	routes         map[string]RouteHandler // 自定义路由："GET /path" → 处理器（精确匹配）
 	wildcardRoutes map[string][]wildcardRoute
-	boxes          *sync.Map              // 依赖容器：reflect.Type → reflect.Value
-	guards         []*any                 // 全局 Guard
-	serviceGuards  map[string][]*any      // 服务级 Guard，按服务名
+	boxes          *sync.Map         // 依赖容器：reflect.Type → reflect.Value
+	guards         []*any            // 全局 Guard
+	serviceGuards  map[string][]*any // 服务级 Guard，按服务名
 }
 
 // wildcardRoute 通配符路由（BindRoute path 以 "/*" 结尾注册）：
@@ -68,16 +68,7 @@ func GetFun() *Fun {
 //
 // guardList 为该服务绑定的 Guard，方法调用前按注册顺序执行
 func (f *Fun) BindService(service any, guardList ...Guard) {
-	t := reflect.TypeOf(service)
-	// 必须是指针指向的结构体，匿名类型无法注册
-	if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
-		panic("fun: BindService requires a pointer to a struct")
-	}
-	name := t.Elem().Name()
-	if name == "" {
-		panic("fun: BindService requires a named type")
-	}
-
+	t, name := serviceType(service)
 	boxWired(service, f)
 
 	serviceGuards := make([]*any, 0, len(guardList))
@@ -86,7 +77,29 @@ func (f *Fun) BindService(service any, guardList ...Guard) {
 		serviceGuards = append(serviceGuards, serviceGuardWired(guard, f))
 	}
 	f.serviceGuards[name] = serviceGuards
+	f.bindServiceMethods(t, name)
+}
 
+// BindServiceForGen registers service metadata for code generation without
+// constructing runtime dependencies or guards.
+func (f *Fun) BindServiceForGen(service any) {
+	t, name := serviceType(service)
+	f.bindServiceMethods(t, name)
+}
+
+func serviceType(service any) (reflect.Type, string) {
+	t := reflect.TypeOf(service)
+	if t == nil || t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
+		panic("fun: BindService requires a pointer to a struct")
+	}
+	name := t.Elem().Name()
+	if name == "" {
+		panic("fun: BindService requires a named type")
+	}
+	return t, name
+}
+
+func (f *Fun) bindServiceMethods(t reflect.Type, name string) {
 	for m := range t.Methods() {
 		m := m
 		// Ctx 命名持有 *fasthttp.RequestCtx（非嵌入），服务方法集只含业务方法，无需过滤提升方法

gen_reliability_test.go

@@ -3,6 +3,7 @@ package fun
 import (
 	"os"
 	"path/filepath"
+	"reflect"
 	"sort"
 	"strings"
 	"testing"
@@ -31,6 +32,16 @@ type ZebraGenSvc struct{}
 
 func (*ZebraGenSvc) Watch() (*Stream, error) { return &Stream{}, nil }
 
+type GenOnlyDependency struct{}
+
+func (*GenOnlyDependency) New() { panic("generation initialized a runtime dependency") }
+
+type DependencyGenSvc struct {
+	Dependency *GenOnlyDependency
+}
+
+func (*DependencyGenSvc) Ping() error { return nil }
+
 func isolateGeneratorGlobals(t *testing.T) {
 	t.Helper()
 	oldFun, oldDirectory := fun, directory
@@ -69,6 +80,18 @@ func generatedFiles(t *testing.T, root string) map[string]string {
 	return files
 }
 
+func TestBindServiceForGenDoesNotInitializeDependencies(t *testing.T) {
+	isolateGeneratorGlobals(t)
+	f := GetFun()
+	f.BindServiceForGen(&DependencyGenSvc{})
+	if _, ok := f.methods["DependencyGenSvc.Ping"]; !ok {
+		t.Fatal("generation-only service method was not registered")
+	}
+	if _, ok := f.boxes.Load(reflect.TypeFor[*GenOnlyDependency]()); ok {
+		t.Fatal("generation-only registration stored a runtime dependency")
+	}
+}
+
 func TestGeneratedTypeScriptSignaturesAndImports(t *testing.T) {
 	isolateGeneratorGlobals(t)
 	f := GetFun()
@@ -87,6 +110,20 @@ func TestGeneratedTypeScriptSignaturesAndImports(t *testing.T) {
 		return string(body)
 	}
 
+	client := read("client.ts")
+	for _, want := range []string{
+		`state?: Record<string, string>;`,
+		`export type ResponseContext = {`,
+		`readonly requestState: Readonly<Record<string, string>>;`,
+		`readonly response?: Response;`,
+		`state = { ...this.state, ...options?.state };`,
+		`interceptor(serviceName, methodName, current, context)`,
+	} {
+		if !strings.Contains(client, want) {
+			t.Errorf("client.ts missing %q:\n%s", want, client)
+		}
+	}
+
 	alpha := read("alphaGenSvc.ts")
 	if first := strings.SplitN(alpha, "\n", 2)[0]; first != `import { Client, type result, type RequestOptions } from "./client";` {
 		t.Fatalf("unexpected request-only imports: %s", first)

template_ts.go

@@ -16,10 +16,12 @@ export type resultStatus = 0 | 1 | 2 | 4 | 5;
 
 export type RequestOptions = {
   signal?: AbortSignal;
+  state?: Record<string, string>;
 };
 
 export type StreamOptions = {
   signal?: AbortSignal;
+  state?: Record<string, string>;
 };
 
 export type RequestInterceptor = (
@@ -29,12 +31,24 @@ export type RequestInterceptor = (
   dto?: any
 ) => Promise<void> | void;
 
+export type ResponseContext = {
+  readonly requestState: Readonly<Record<string, string>>;
+  readonly response?: Response;
+};
+
 export type ResponseInterceptor = (
   serviceName: string,
   methodName: string,
   result: result<any>
 ) => Promise<result<any> | void> | result<any> | void;
 
+export type ContextResponseInterceptor = (
+  serviceName: string,
+  methodName: string,
+  result: result<any>,
+  context: ResponseContext
+) => Promise<result<any> | void> | result<any> | void;
+
 function messageOf(error: unknown): string {
   if (error instanceof Error && error.message) return error.message;
   if (typeof error === "string" && error) return error;
@@ -137,7 +151,7 @@ export class Client {
   private url: string;
   private state: Record<string, string> = {};
   private requestInterceptors: RequestInterceptor[] = [];
-  private responseInterceptors: ResponseInterceptor[] = [];
+  private responseInterceptors: ContextResponseInterceptor[] = [];
 
   constructor(url: string) {
     this.url = url.replace(/\/+$/, "");
@@ -151,19 +165,26 @@ export class Client {
     this.requestInterceptors.push(interceptor);
   }
 
-  addResponseInterceptor(interceptor: ResponseInterceptor) {
-    this.responseInterceptors.push(interceptor);
+  addResponseInterceptor(interceptor: ResponseInterceptor): void;
+  addResponseInterceptor(interceptor: ContextResponseInterceptor): void;
+  addResponseInterceptor(interceptor: ResponseInterceptor | ContextResponseInterceptor) {
+    this.responseInterceptors.push(interceptor as ContextResponseInterceptor);
   }
 
   private async interceptResponse(
     serviceName: string,
     methodName: string,
-    initial: result<any>
+    initial: result<any>,
+    requestState: Readonly<Record<string, string>>,
+    response?: Response
   ): Promise<result<any>> {
     let current = initial;
+    const context: ResponseContext = Object.freeze(
+      response === undefined ? { requestState } : { requestState, response }
+    );
     for (const interceptor of this.responseInterceptors) {
       try {
-        const replaced = await interceptor(serviceName, methodName, current);
+        const replaced = await interceptor(serviceName, methodName, current, context);
         if (replaced) current = replaced;
       } catch (error) {
         current = failure(1, ` + "`Response interceptor failed: ${messageOf(error)}`" + `);
@@ -172,12 +193,19 @@ export class Client {
     return current;
   }
 
-  private async requestState(serviceName: string, methodName: string, dto: any): Promise<Record<string, string>> {
-    const state: Record<string, string> = { ...this.state };
+  private async interceptRequest(
+    serviceName: string,
+    methodName: string,
+    state: Record<string, string>,
+    dto: any
+  ): Promise<void> {
     for (const interceptor of this.requestInterceptors) {
       await interceptor(serviceName, methodName, state, dto);
     }
-    return state;
+  }
+
+  private snapshotState(state: Record<string, string>): Readonly<Record<string, string>> {
+    return Object.freeze({ ...state });
   }
 
   async request<T>(
@@ -188,12 +216,45 @@ export class Client {
   ): Promise<result<T>> {
     let state: Record<string, string>;
     try {
-      state = await this.requestState(serviceName, methodName, dto);
+      state = { ...this.state, ...options?.state };
     } catch (error) {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        failure(1, ` + "`Request interceptor failed: ${messageOf(error)}`" + `)
+        failure(1, ` + "`Could not prepare request state: ${messageOf(error)}`" + `),
+        Object.freeze({})
+      ) as result<T>;
+    }
+    try {
+      await this.interceptRequest(serviceName, methodName, state, dto);
+    } catch (error) {
+      let requestState: Readonly<Record<string, string>>;
+      try {
+        requestState = this.snapshotState(state);
+      } catch (snapshotError) {
+        return await this.interceptResponse(
+          serviceName,
+          methodName,
+          failure(1, ` + "`Could not snapshot request state: ${messageOf(snapshotError)}`" + `),
+          Object.freeze({})
+        ) as result<T>;
+      }
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        failure(1, ` + "`Request interceptor failed: ${messageOf(error)}`" + `),
+        requestState
+      ) as result<T>;
+    }
+    let requestState: Readonly<Record<string, string>>;
+    try {
+      requestState = this.snapshotState(state);
+    } catch (error) {
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        failure(1, ` + "`Could not snapshot request state: ${messageOf(error)}`" + `),
+        Object.freeze({})
       ) as result<T>;
     }
 
@@ -203,7 +264,7 @@ export class Client {
         serviceName,
         methodName,
         data: dto,
-        ...(Object.keys(state).length ? { state } : {}),
+        ...(Object.keys(requestState).length ? { state: requestState } : {}),
       });
       if (serialized === undefined) throw new Error("serialization produced no output");
       body = serialized;
@@ -211,13 +272,15 @@ export class Client {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        failure(1, ` + "`Could not serialize request: ${messageOf(error)}`" + `)
+        failure(1, ` + "`Could not serialize request: ${messageOf(error)}`" + `),
+        requestState
       ) as result<T>;
     }
 
     let output: result<any>;
+    let response: Response | undefined;
     try {
-      const response = await fetch(` + "`${this.url}/cell`" + `, {
+      response = await fetch(` + "`${this.url}/cell`" + `, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body,
@@ -231,7 +294,7 @@ export class Client {
     } catch (error) {
       output = requestFailure(error, options?.signal, false);
     }
-    return await this.interceptResponse(serviceName, methodName, output) as result<T>;
+    return await this.interceptResponse(serviceName, methodName, output, requestState, response) as result<T>;
   }
 
   async stream<T>(
@@ -243,12 +306,45 @@ export class Client {
   ): Promise<result<void>> {
     let state: Record<string, string>;
     try {
-      state = await this.requestState(serviceName, methodName, dto);
+      state = { ...this.state, ...options?.state };
     } catch (error) {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        failure(1, ` + "`Request interceptor failed: ${messageOf(error)}`" + `)
+        failure(1, ` + "`Could not prepare request state: ${messageOf(error)}`" + `),
+        Object.freeze({})
+      );
+    }
+    try {
+      await this.interceptRequest(serviceName, methodName, state, dto);
+    } catch (error) {
+      let requestState: Readonly<Record<string, string>>;
+      try {
+        requestState = this.snapshotState(state);
+      } catch (snapshotError) {
+        return await this.interceptResponse(
+          serviceName,
+          methodName,
+          failure(1, ` + "`Could not snapshot request state: ${messageOf(snapshotError)}`" + `),
+          Object.freeze({})
+        );
+      }
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        failure(1, ` + "`Request interceptor failed: ${messageOf(error)}`" + `),
+        requestState
+      );
+    }
+    let requestState: Readonly<Record<string, string>>;
+    try {
+      requestState = this.snapshotState(state);
+    } catch (error) {
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        failure(1, ` + "`Could not snapshot request state: ${messageOf(error)}`" + `),
+        Object.freeze({})
       );
     }
 
@@ -258,7 +354,7 @@ export class Client {
         serviceName,
         methodName,
         data: dto,
-        ...(Object.keys(state).length ? { state } : {}),
+        ...(Object.keys(requestState).length ? { state: requestState } : {}),
       });
       if (serialized === undefined) throw new Error("serialization produced no output");
       body = serialized;
@@ -266,7 +362,8 @@ export class Client {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        failure(1, ` + "`Could not serialize request: ${messageOf(error)}`" + `)
+        failure(1, ` + "`Could not serialize request: ${messageOf(error)}`" + `),
+        requestState
       );
     }
 
@@ -282,7 +379,8 @@ export class Client {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        requestFailure(error, options?.signal, true)
+        requestFailure(error, options?.signal, true),
+        requestState
       );
     }
 
@@ -294,10 +392,18 @@ export class Client {
         return await this.interceptResponse(
           serviceName,
           methodName,
-          responseReadFailure(error, response, options?.signal, true)
+          responseReadFailure(error, response, options?.signal, true),
+          requestState,
+          response
         );
       }
-      return await this.interceptResponse(serviceName, methodName, parseResult(response, text));
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        parseResult(response, text),
+        requestState,
+        response
+      );
     }
 
     if (mediaType(response) !== "application/x-ndjson") {
@@ -308,7 +414,9 @@ export class Client {
         return await this.interceptResponse(
           serviceName,
           methodName,
-          responseReadFailure(error, response, options?.signal, true)
+          responseReadFailure(error, response, options?.signal, true),
+          requestState,
+          response
         );
       }
       const rpcResult = parseResult(response, text);
@@ -317,12 +425,20 @@ export class Client {
         methodName,
         rpcResult.status === 0
           ? failure(1, "Expected application/x-ndjson response")
-          : rpcResult
+          : rpcResult,
+        requestState,
+        response
       );
     }
 
     if (!response.body) {
-      return await this.interceptResponse(serviceName, methodName, { status: 0 });
+      return await this.interceptResponse(
+        serviceName,
+        methodName,
+        { status: 0 },
+        requestState,
+        response
+      );
     }
 
     let reader: ReadableStreamDefaultReader<Uint8Array>;
@@ -332,7 +448,9 @@ export class Client {
       return await this.interceptResponse(
         serviceName,
         methodName,
-        responseReadFailure(error, response, options?.signal, true)
+        responseReadFailure(error, response, options?.signal, true),
+        requestState,
+        response
       );
     }
     const decoder = new TextDecoder("utf-8", { fatal: true });
@@ -426,7 +544,9 @@ export class Client {
     return await this.interceptResponse(
       serviceName,
       methodName,
-      failed || { status: 0 }
+      failed || { status: 0 },
+      requestState,
+      response
     );
   }
 }`