[ADDED] Service api improvements (#1160)

Co-authored-by: Tomasz Pietrek <melgaer@gmail.com>

js.go

@@ -1528,13 +1528,11 @@ func (js *js) subscribe(subj, queue string, cb MsgHandler, ch chan *Msg, isSync,
 	}
 
 	// Find the stream mapped to the subject if not bound to a stream already.
-	if o.stream == _EMPTY_ {
+	if stream == _EMPTY_ {
 		stream, err = js.StreamNameBySubject(subj)
 		if err != nil {
 			return nil, err
 		}
-	} else {
-		stream = o.stream
 	}
 
 	// With an explicit durable name, we can lookup the consumer first

micro/example_package_test.go

@@ -0,0 +1,84 @@
+// Copyright 2022 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package micro
+
+import (
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	"github.com/nats-io/nats.go"
+)
+
+func Example() {
+	s := RunServerOnPort(-1)
+	defer s.Shutdown()
+
+	nc, err := nats.Connect(s.ClientURL())
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	// Service handler is a function which takes Service.Request as argument.
+	// req.Respond or req.Error should be used to respond to the request.
+	incrementHandler := func(req *Request) error {
+		val, err := strconv.Atoi(string(req.Data))
+		if err != nil {
+			req.Error("400", "request data should be a number", nil)
+			return nil
+		}
+
+		responseData := val + 1
+		req.Respond([]byte(strconv.Itoa(responseData)))
+		return nil
+	}
+
+	config := Config{
+		Name:        "IncrementService",
+		Version:     "0.1.0",
+		Description: "Increment numbers",
+		Endpoint: Endpoint{
+			// service handler
+			Handler: incrementHandler,
+			// a unique subject serving as a service endpoint
+			Subject: "numbers.increment",
+		},
+	}
+	// Multiple instances of the servcice with the same name can be created.
+	// Requests to a service with the same name will be load-balanced.
+	for i := 0; i < 5; i++ {
+		svc, err := AddService(nc, config)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer svc.Stop()
+	}
+
+	// send a request to a service
+	resp, err := nc.Request("numbers.increment", []byte("3"), 1*time.Second)
+	if err != nil {
+		log.Fatal(err)
+	}
+	responseVal, err := strconv.Atoi(string(resp.Data))
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(responseVal)
+
+	//
+	// Output: 4
+	//
+}

micro/example_test.go

@@ -0,0 +1,267 @@
+// Copyright 2022 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package micro
+
+import (
+	"fmt"
+	"log"
+	"reflect"
+
+	"github.com/nats-io/nats.go"
+)
+
+func ExampleAddService() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	echoHandler := func(req *Request) error {
+		req.Respond(req.Data)
+		return nil
+	}
+
+	config := Config{
+		Name:        "EchoService",
+		Version:     "v1.0.0",
+		Description: "Send back what you receive",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: echoHandler,
+		},
+
+		// DoneHandler can be set to customize behavior on stopping a service.
+		DoneHandler: func(srv Service) {
+			info := srv.Info()
+			fmt.Printf("stopped service %q with ID %q\n", info.Name, info.ID)
+		},
+
+		// ErrorHandler can be used to customize behavior on service execution error.
+		ErrorHandler: func(srv Service, err *NATSError) {
+			info := srv.Info()
+			fmt.Printf("Service %q returned an error on subject %q: %s", info.Name, err.Subject, err.Description)
+		},
+	}
+
+	srv, err := AddService(nc, config)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer srv.Stop()
+}
+
+func ExampleService_Info() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	config := Config{
+		Name: "EchoService",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: func(*Request) error { return nil },
+		},
+	}
+
+	srv, _ := AddService(nc, config)
+
+	// service info
+	info := srv.Info()
+
+	fmt.Println(info.ID)
+	fmt.Println(info.Name)
+	fmt.Println(info.Description)
+	fmt.Println(info.Version)
+	fmt.Println(info.Subject)
+}
+
+func ExampleService_Stats() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	config := Config{
+		Name:    "EchoService",
+		Version: "0.1.0",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: func(*Request) error { return nil },
+		},
+	}
+
+	srv, _ := AddService(nc, config)
+
+	// stats of a service instance
+	stats := srv.Stats()
+
+	fmt.Println(stats.AverageProcessingTime)
+	fmt.Println(stats.ProcessingTime)
+
+}
+
+func ExampleService_Stop() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	config := Config{
+		Name:    "EchoService",
+		Version: "0.1.0",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: func(*Request) error { return nil },
+		},
+	}
+
+	srv, _ := AddService(nc, config)
+
+	// stop a service
+	err = srv.Stop()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// stop is idempotent so multiple executions will not return an error
+	err = srv.Stop()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func ExampleService_Stopped() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	config := Config{
+		Name:    "EchoService",
+		Version: "0.1.0",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: func(*Request) error { return nil },
+		},
+	}
+
+	srv, _ := AddService(nc, config)
+
+	// stop a service
+	err = srv.Stop()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if srv.Stopped() {
+		fmt.Println("service stopped")
+	}
+}
+
+func ExampleService_Reset() {
+	nc, err := nats.Connect("127.0.0.1:4222")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer nc.Close()
+
+	config := Config{
+		Name:    "EchoService",
+		Version: "0.1.0",
+		Endpoint: Endpoint{
+			Subject: "echo",
+			Handler: func(*Request) error { return nil },
+		},
+	}
+
+	srv, _ := AddService(nc, config)
+
+	// reset endpoint stats on this service
+	srv.Reset()
+
+	empty := Stats{
+		ServiceIdentity: srv.Info().ServiceIdentity,
+	}
+	if !reflect.DeepEqual(srv.Stats(), empty) {
+		log.Fatal("Expected endpoint stats to be empty")
+	}
+}
+
+func ExampleControlSubject() {
+
+	// subject used to get PING from all services
+	subjectPINGAll, _ := ControlSubject(PingVerb, "", "")
+	fmt.Println(subjectPINGAll)
+
+	// subject used to get PING from services with provided name
+	subjectPINGName, _ := ControlSubject(PingVerb, "CoolService", "")
+	fmt.Println(subjectPINGName)
+
+	// subject used to get PING from a service with provided name and ID
+	subjectPINGInstance, _ := ControlSubject(PingVerb, "CoolService", "123")
+	fmt.Println(subjectPINGInstance)
+
+	// Output:
+	// $SRV.PING
+	// $SRV.PING.COOLSERVICE
+	// $SRV.PING.COOLSERVICE.123
+}
+
+func ExampleRequest_Respond() {
+	handler := func(req *Request) {
+		// respond to the request
+		if err := req.Respond(req.Data); err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	fmt.Printf("%T", handler)
+}
+
+func ExampleRequest_RespondJSON() {
+	type Point struct {
+		X int `json:"x"`
+		Y int `json:"y"`
+	}
+
+	handler := func(req *Request) {
+		resp := Point{5, 10}
+		// respond to the request
+		// response will be serialized to {"x":5,"y":10}
+		if err := req.RespondJSON(resp); err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	fmt.Printf("%T", handler)
+}
+
+func ExampleRequest_Error() {
+	handler := func(req *Request) error {
+		// respond with an error
+		// Error sets Nats-Service-Error and Nats-Service-Error-Code headers in the response
+		if err := req.Error("400", "bad request", []byte(`{"error": "value should be a number"}`)); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	fmt.Printf("%T", handler)
+}

micro/request.go

@@ -0,0 +1,79 @@
+// Copyright 2022 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package micro
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/nats-io/nats.go"
+)
+
+type (
+	Request struct {
+		*nats.Msg
+	}
+
+	// RequestHandler is a function used as a Handler for a service.
+	// It takes a request, which contains the data (payload and headers) of the request,
+	// as well as exposes methods to respond to the request.
+	//
+	// RequestHandler returns an error - if returned, the request will be accounted form in stats (in num_requests),
+	// and last_error will be set with the value.
+	RequestHandler func(*Request) error
+)
+
+var (
+	ErrRespond         = errors.New("NATS error when sending response")
+	ErrMarshalResponse = errors.New("marshaling response")
+	ErrArgRequired     = errors.New("argument required")
+)
+
+func (r *Request) Respond(response []byte) error {
+	if err := r.Msg.Respond(response); err != nil {
+		return fmt.Errorf("%w: %s", ErrRespond, err)
+	}
+
+	return nil
+}
+
+func (r *Request) RespondJSON(response interface{}) error {
+	resp, err := json.Marshal(response)
+	if err != nil {
+		return ErrMarshalResponse
+	}
+
+	return r.Respond(resp)
+}
+
+// Error prepares and publishes error response from a handler.
+// A response error should be set containing an error code and description.
+// Optionally, data can be set as response payload.
+func (r *Request) Error(code, description string, data []byte) error {
+	if code == "" {
+		return fmt.Errorf("%w: error code", ErrArgRequired)
+	}
+	if description == "" {
+		return fmt.Errorf("%w: description", ErrArgRequired)
+	}
+	response := &nats.Msg{
+		Header: nats.Header{
+			ErrorHeader:     []string{description},
+			ErrorCodeHeader: []string{code},
+		},
+	}
+	response.Data = data
+	return r.RespondMsg(response)
+}

micro/service.go

@@ -0,0 +1,592 @@
+// Copyright 2022 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package micro
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/nats-io/nats.go"
+	"github.com/nats-io/nuid"
+)
+
+// Notice: Experimental Preview
+//
+// This functionality is EXPERIMENTAL and may be changed in later releases.
+
+type (
+	Service interface {
+		// Info returns the service info.
+		Info() Info
+
+		// Stats returns statisctics for the service endpoint and all monitoring endpoints.
+		Stats() Stats
+
+		// Reset resets all statistics on a service instance.
+		Reset()
+
+		// Stop drains the endpoint subscriptions and marks the service as stopped.
+		Stop() error
+
+		// Stopped informs whether [Stop] was executed on the service.
+		Stopped() bool
+	}
+
+	// ErrHandler is a function used to configure a custom error handler for a service,
+	ErrHandler func(Service, *NATSError)
+
+	// DoneHandler is a function used to configure a custom done handler for a service.
+	DoneHandler func(Service)
+
+	// StatsHandleris a function used to configure a custom STATS endpoint.
+	// It should return a value which can be serialized to JSON.
+	StatsHandler func(Endpoint) interface{}
+
+	// ServiceIdentity contains fields helping to identidy a service instance.
+	ServiceIdentity struct {
+		Name    string `json:"name"`
+		ID      string `json:"id"`
+		Version string `json:"version"`
+	}
+
+	// Stats is the type returned by STATS monitoring endpoint.
+	// It contains stats for a specific endpoint (either request handler or monitoring enpoints).
+	Stats struct {
+		ServiceIdentity
+		NumRequests           int             `json:"num_requests"`
+		NumErrors             int             `json:"num_errors"`
+		LastError             string          `json:"last_error"`
+		ProcessingTime        time.Duration   `json:"processing_time"`
+		AverageProcessingTime time.Duration   `json:"average_processing_time"`
+		Started               string          `json:"started"`
+		Data                  json.RawMessage `json:"data,omitempty"`
+	}
+
+	// Ping is the response type for PING monitoring endpoint.
+	Ping ServiceIdentity
+
+	// Info is the basic information about a service type.
+	Info struct {
+		ServiceIdentity
+		Description string `json:"description"`
+		Subject     string `json:"subject"`
+	}
+
+	// SchemaResp is the response value for SCHEMA requests.
+	SchemaResp struct {
+		ServiceIdentity
+		Schema Schema `json:"schema"`
+	}
+
+	// Schema can be used to configure a schema for a service.
+	// It is olso returned by the SCHEMA monitoring service (if set).
+	Schema struct {
+		Request  string `json:"request"`
+		Response string `json:"response"`
+	}
+
+	// Endpoint is used to configure a subject and handler for a service.
+	Endpoint struct {
+		Subject string `json:"subject"`
+		Handler RequestHandler
+	}
+
+	// Verb represents a name of the monitoring service.
+	Verb int64
+
+	// Config is a configuration of a service.
+	Config struct {
+		Name         string   `json:"name"`
+		Version      string   `json:"version"`
+		Description  string   `json:"description"`
+		Schema       Schema   `json:"schema"`
+		Endpoint     Endpoint `json:"endpoint"`
+		StatsHandler StatsHandler
+		DoneHandler  DoneHandler
+		ErrorHandler ErrHandler
+	}
+
+	// NATSError represents an error returned by a NATS Subscription.
+	// It contains a subject on which the subscription failed, so that
+	// it can be linked with a specific service endpoint.
+	NATSError struct {
+		Subject     string
+		Description string
+	}
+
+	// service represents a configured NATS service.
+	// It should be created using [Add] in order to configure the appropriate NATS subscriptions
+	// for request handler and monitoring.
+	service struct {
+		// Config contains a configuration of the service
+		Config
+
+		m            sync.Mutex
+		id           string
+		reqSub       *nats.Subscription
+		verbSubs     map[string]*nats.Subscription
+		stats        *Stats
+		conn         *nats.Conn
+		natsHandlers handlers
+		stopped      bool
+
+		asyncDispatcher asyncCallbacksHandler
+	}
+
+	handlers struct {
+		closed   nats.ConnHandler
+		asyncErr nats.ErrHandler
+	}
+
+	asyncCallbacksHandler struct {
+		cbQueue chan func()
+	}
+)
+
+const (
+	// Queue Group name used across all services
+	QG = "q"
+
+	// APIPrefix is the root of all control subjects
+	APIPrefix = "$SRV"
+)
+
+// Service Error headers
+const (
+	ErrorHeader     = "Nats-Service-Error"
+	ErrorCodeHeader = "Nats-Service-Error-Code"
+)
+
+// Verbs being used to set up a specific control subject.
+const (
+	PingVerb Verb = iota
+	StatsVerb
+	InfoVerb
+	SchemaVerb
+)
+
+var (
+	// this regular expression is suggested regexp for semver validation: https://semver.org/
+	semVerRegexp      = regexp.MustCompile(`^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`)
+	serviceNameRegexp = regexp.MustCompile(`^[A-Za-z0-9\-_]+$`)
+)
+
+// Common errors returned by the Service framework.
+var (
+	// ErrConfigValidation is returned when service configuration is invalid
+	ErrConfigValidation = errors.New("validation")
+
+	// ErrVerbNotSupported is returned when invalid [Verb] is used (PING, SCHEMA, INFO, STATS)
+	ErrVerbNotSupported = errors.New("unsupported verb")
+
+	// ErrServiceNameRequired is returned when attempting to generate control subject with ID but empty name
+	ErrServiceNameRequired = errors.New("service name is required to generate ID control subject")
+)
+
+func (s Verb) String() string {
+	switch s {
+	case PingVerb:
+		return "PING"
+	case StatsVerb:
+		return "STATS"
+	case InfoVerb:
+		return "INFO"
+	case SchemaVerb:
+		return "SCHEMA"
+	default:
+		return ""
+	}
+}
+
+// AddService adds a microservice.
+// It will enable internal common services (PING, STATS, INFO and SCHEMA) as well as
+// the actual service handler on the subject provided in config.Endpoint
+// A service name, version and Endpoint configuration are required to add a service.
+// AddService returns a [Service] interface, allowing service menagement.
+// Each service is assigned a unique ID.
+func AddService(nc *nats.Conn, config Config) (Service, error) {
+	if err := config.valid(); err != nil {
+		return nil, err
+	}
+
+	id := nuid.Next()
+	svc := &service{
+		Config: config,
+		conn:   nc,
+		id:     id,
+		asyncDispatcher: asyncCallbacksHandler{
+			cbQueue: make(chan func(), 100),
+		},
+	}
+	svcIdentity := ServiceIdentity{
+		Name:    config.Name,
+		ID:      id,
+		Version: config.Version,
+	}
+	svc.verbSubs = make(map[string]*nats.Subscription)
+	svc.stats = &Stats{
+		ServiceIdentity: svcIdentity,
+	}
+
+	svc.setupAsyncCallbacks()
+
+	go svc.asyncDispatcher.asyncCBDispatcher()
+
+	// Setup internal subscriptions.
+	var err error
+
+	svc.reqSub, err = nc.QueueSubscribe(config.Endpoint.Subject, QG, func(m *nats.Msg) {
+		svc.reqHandler(&Request{Msg: m})
+	})
+	if err != nil {
+		svc.asyncDispatcher.close()
+		return nil, err
+	}
+
+	ping := Ping(svcIdentity)
+
+	infoHandler := func(req *Request) error {
+		response, _ := json.Marshal(svc.Info())
+		if err := req.Respond(response); err != nil {
+			if err := req.Error("500", fmt.Sprintf("Error handling INFO request: %s", err), nil); err != nil && config.ErrorHandler != nil {
+				svc.asyncDispatcher.push(func() { config.ErrorHandler(svc, &NATSError{req.Subject, err.Error()}) })
+			}
+		}
+		return nil
+	}
+
+	pingHandler := func(req *Request) error {
+		response, _ := json.Marshal(ping)
+		if err := req.Respond(response); err != nil {
+			if err := req.Error("500", fmt.Sprintf("Error handling PING request: %s", err), nil); err != nil && config.ErrorHandler != nil {
+				svc.asyncDispatcher.push(func() { config.ErrorHandler(svc, &NATSError{req.Subject, err.Error()}) })
+			}
+		}
+		return nil
+	}
+
+	statsHandler := func(req *Request) error {
+		response, _ := json.Marshal(svc.Stats())
+		if err := req.Respond(response); err != nil {
+			if err := req.Error("500", fmt.Sprintf("Error handling STATS request: %s", err), nil); err != nil && config.ErrorHandler != nil {
+				svc.asyncDispatcher.push(func() { config.ErrorHandler(svc, &NATSError{req.Subject, err.Error()}) })
+			}
+		}
+		return nil
+	}
+
+	schema := SchemaResp{
+		ServiceIdentity: svcIdentity,
+		Schema:          config.Schema,
+	}
+	schemaHandler := func(req *Request) error {
+		response, _ := json.Marshal(schema)
+		if err := req.Respond(response); err != nil {
+			if err := req.Error("500", fmt.Sprintf("Error handling SCHEMA request: %s", err), nil); err != nil && config.ErrorHandler != nil {
+				svc.asyncDispatcher.push(func() { config.ErrorHandler(svc, &NATSError{req.Subject, err.Error()}) })
+			}
+		}
+		return nil
+	}
+
+	if err := svc.verbHandlers(nc, InfoVerb, infoHandler); err != nil {
+		svc.asyncDispatcher.close()
+		return nil, err
+	}
+	if err := svc.verbHandlers(nc, PingVerb, pingHandler); err != nil {
+		svc.asyncDispatcher.close()
+		return nil, err
+	}
+	if err := svc.verbHandlers(nc, StatsVerb, statsHandler); err != nil {
+		svc.asyncDispatcher.close()
+		return nil, err
+	}
+
+	if err := svc.verbHandlers(nc, SchemaVerb, schemaHandler); err != nil {
+		svc.asyncDispatcher.close()
+		return nil, err
+	}
+	svc.stats.Started = time.Now().Format(time.RFC3339)
+
+	return svc, nil
+}
+
+// dispatch is responsible for calling any async callbacks
+func (ac *asyncCallbacksHandler) asyncCBDispatcher() {
+	for {
+		f := <-ac.cbQueue
+		if f == nil {
+			return
+		}
+		f()
+	}
+}
+
+// dispatch is responsible for calling any async callbacks
+func (ac *asyncCallbacksHandler) push(f func()) {
+	ac.cbQueue <- f
+}
+
+func (ac *asyncCallbacksHandler) close() {
+	close(ac.cbQueue)
+}
+
+func (s *Config) valid() error {
+	if !serviceNameRegexp.MatchString(s.Name) {
+		return fmt.Errorf("%w: service name: name should not be empty and should consist of alphanumerical charactest, dashes and underscores", ErrConfigValidation)
+	}
+	if !semVerRegexp.MatchString(s.Version) {
+		return fmt.Errorf("%w: version: version should not be empty should match the SemVer format", ErrConfigValidation)
+	}
+	return s.Endpoint.valid()
+}
+
+func (e *Endpoint) valid() error {
+	if e.Subject == "" {
+		return fmt.Errorf("%w: endpoint: subject is required", ErrConfigValidation)
+	}
+	if e.Handler == nil {
+		return fmt.Errorf("%w: endpoint: handler is required", ErrConfigValidation)
+	}
+	return nil
+}
+
+func (svc *service) setupAsyncCallbacks() {
+	svc.natsHandlers.closed = svc.conn.ClosedHandler()
+	if svc.natsHandlers.closed != nil {
+		svc.conn.SetClosedHandler(func(c *nats.Conn) {
+			svc.Stop()
+			svc.natsHandlers.closed(c)
+		})
+	} else {
+		svc.conn.SetClosedHandler(func(c *nats.Conn) {
+			svc.Stop()
+		})
+	}
+
+	svc.natsHandlers.asyncErr = svc.conn.ErrorHandler()
+	if svc.natsHandlers.asyncErr != nil {
+		svc.conn.SetErrorHandler(func(c *nats.Conn, s *nats.Subscription, err error) {
+			if !svc.matchSubscriptionSubject(s.Subject) {
+				svc.natsHandlers.asyncErr(c, s, err)
+			}
+			if svc.Config.ErrorHandler != nil {
+				svc.Config.ErrorHandler(svc, &NATSError{
+					Subject:     s.Subject,
+					Description: err.Error(),
+				})
+			}
+			svc.Stop()
+			svc.natsHandlers.asyncErr(c, s, err)
+		})
+	} else {
+		svc.conn.SetErrorHandler(func(c *nats.Conn, s *nats.Subscription, err error) {
+			if !svc.matchSubscriptionSubject(s.Subject) {
+				return
+			}
+			if svc.Config.ErrorHandler != nil {
+				svc.Config.ErrorHandler(svc, &NATSError{
+					Subject:     s.Subject,
+					Description: err.Error(),
+				})
+			}
+			svc.Stop()
+		})
+	}
+}
+
+func (svc *service) matchSubscriptionSubject(subj string) bool {
+	if svc.reqSub.Subject == subj {
+		return true
+	}
+	for _, verbSub := range svc.verbSubs {
+		if verbSub.Subject == subj {
+			return true
+		}
+	}
+	return false
+}
+
+// verbHandlers generates control handlers for a specific verb.
+// Each request generates 3 subscriptions, one for the general verb
+// affecting all services written with the framework, one that handles
+// all services of a particular kind, and finally a specific service instance.
+func (svc *service) verbHandlers(nc *nats.Conn, verb Verb, handler RequestHandler) error {
+	name := fmt.Sprintf("%s-all", verb.String())
+	if err := svc.addInternalHandler(nc, verb, "", "", name, handler); err != nil {
+		return err
+	}
+	name = fmt.Sprintf("%s-kind", verb.String())
+	if err := svc.addInternalHandler(nc, verb, svc.Config.Name, "", name, handler); err != nil {
+		return err
+	}
+	return svc.addInternalHandler(nc, verb, svc.Config.Name, svc.id, verb.String(), handler)
+}
+
+// addInternalHandler registers a control subject handler.
+func (s *service) addInternalHandler(nc *nats.Conn, verb Verb, kind, id, name string, handler RequestHandler) error {
+	subj, err := ControlSubject(verb, kind, id)
+	if err != nil {
+		s.Stop()
+		return err
+	}
+
+	s.verbSubs[name], err = nc.Subscribe(subj, func(msg *nats.Msg) {
+		handler(&Request{Msg: msg})
+	})
+	if err != nil {
+		s.Stop()
+		return err
+	}
+	return nil
+}
+
+// reqHandler itself
+func (s *service) reqHandler(req *Request) {
+	start := time.Now()
+	err := s.Endpoint.Handler(req)
+	s.m.Lock()
+	s.stats.NumRequests++
+	s.stats.ProcessingTime += time.Since(start)
+	avgProcessingTime := s.stats.ProcessingTime.Nanoseconds() / int64(s.stats.NumRequests)
+	s.stats.AverageProcessingTime = time.Duration(avgProcessingTime)
+
+	if err != nil {
+		s.stats.NumErrors++
+		s.stats.LastError = err.Error()
+	}
+	s.m.Unlock()
+}
+
+// Stop drains the endpoint subscriptions and marks the service as stopped.
+func (s *service) Stop() error {
+	s.m.Lock()
+	if s.stopped {
+		return nil
+	}
+	defer s.m.Unlock()
+	if s.reqSub != nil {
+		if err := s.reqSub.Drain(); err != nil {
+			return fmt.Errorf("draining subscription for request handler: %w", err)
+		}
+		s.reqSub = nil
+	}
+	var keys []string
+	for key, sub := range s.verbSubs {
+		keys = append(keys, key)
+		if err := sub.Drain(); err != nil {
+			return fmt.Errorf("draining subscription for subject %q: %w", sub.Subject, err)
+		}
+	}
+	for _, key := range keys {
+		delete(s.verbSubs, key)
+	}
+	restoreAsyncHandlers(s.conn, s.natsHandlers)
+	s.stopped = true
+	if s.DoneHandler != nil {
+		s.asyncDispatcher.push(func() { s.DoneHandler(s) })
+		s.asyncDispatcher.close()
+	}
+	return nil
+}
+
+func restoreAsyncHandlers(nc *nats.Conn, handlers handlers) {
+	nc.SetClosedHandler(handlers.closed)
+	nc.SetErrorHandler(handlers.asyncErr)
+}
+
+// ID returns the service instance's unique ID.
+func (s *service) Info() Info {
+	return Info{
+		ServiceIdentity: ServiceIdentity{
+			Name:    s.Config.Name,
+			ID:      s.id,
+			Version: s.Config.Version,
+		},
+		Description: s.Config.Description,
+		Subject:     s.Config.Endpoint.Subject,
+	}
+}
+
+// Stats returns statisctics for the service endpoint and all monitoring endpoints.
+func (s *service) Stats() Stats {
+	s.m.Lock()
+	defer s.m.Unlock()
+	if s.StatsHandler != nil {
+		s.stats.Data, _ = json.Marshal(s.StatsHandler(s.Endpoint))
+	}
+	info := s.Info()
+	return Stats{
+		ServiceIdentity: ServiceIdentity{
+			Name:    info.Name,
+			ID:      info.ID,
+			Version: info.Version,
+		},
+		NumRequests:           s.stats.NumRequests,
+		NumErrors:             s.stats.NumErrors,
+		ProcessingTime:        s.stats.ProcessingTime,
+		AverageProcessingTime: s.stats.AverageProcessingTime,
+		Started:               s.stats.Started,
+		Data:                  s.stats.Data,
+	}
+}
+
+// Reset resets all statistics on a service instance.
+func (s *service) Reset() {
+	s.m.Lock()
+	s.stats = &Stats{
+		ServiceIdentity: s.Info().ServiceIdentity,
+	}
+	s.m.Unlock()
+}
+
+// Stopped informs whether [Stop] was executed on the service.
+func (s *service) Stopped() bool {
+	s.m.Lock()
+	defer s.m.Unlock()
+	return s.stopped
+}
+
+// ControlSubject returns monitoring subjects used by the Service.
+// Providing a verb is mandatory (it should be one of Ping, Schema, Info or Stats).
+// Depending on whether kind and id are provided, ControlSubject will return one of the following:
+//   - verb only: subject used to monitor all available services
+//   - verb and kind: subject used to monitor services with the provided name
+//   - verb, name and id: subject used to monitor an instance of a service with the provided ID
+func ControlSubject(verb Verb, name, id string) (string, error) {
+	verbStr := verb.String()
+	if verbStr == "" {
+		return "", fmt.Errorf("%w: %q", ErrVerbNotSupported, verbStr)
+	}
+	if name == "" && id != "" {
+		return "", ErrServiceNameRequired
+	}
+	name = strings.ToUpper(name)
+	if name == "" && id == "" {
+		return fmt.Sprintf("%s.%s", APIPrefix, verbStr), nil
+	}
+	if id == "" {
+		return fmt.Sprintf("%s.%s.%s", APIPrefix, verbStr, name), nil
+	}
+	return fmt.Sprintf("%s.%s.%s.%s", APIPrefix, verbStr, name, id), nil
+}
+
+func (e *NATSError) Error() string {
+	return fmt.Sprintf("%q: %s", e.Subject, e.Description)
+}

netchan.go

@@ -1,4 +1,4 @@
-// Copyright 2013-2018 The NATS Authors
+// Copyright 2013-2022 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

parser.go

@@ -1,4 +1,4 @@
-// Copyright 2012-2020 The NATS Authors
+// Copyright 2012-2122 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

services/errors.go

@@ -1,25 +0,0 @@
-// Copyright 2022 The NATS Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package services
-
-import "fmt"
-
-type ServiceAPIError struct {
-	ErrorCode   int
-	Description string
-}
-
-func (e *ServiceAPIError) Error() string {
-	return fmt.Sprintf("%d %s", e.ErrorCode, e.Description)
-}

services/service.go

@@ -1,404 +0,0 @@
-// Copyright 2022 The NATS Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package services
-
-import (
-	"encoding/json"
-	"errors"
-	"fmt"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/nats-io/nats.go"
-	"github.com/nats-io/nuid"
-)
-
-// Notice: Experimental Preview
-//
-// This functionality is EXPERIMENTAL and may be changed in later releases.
-
-type (
-
-	// Service is an interface for service management.
-	// It exposes methods to stop/reset a service, as well as get information on a service.
-	Service interface {
-		ID() string
-		Name() string
-		Description() string
-		Version() string
-		Stats() ServiceStats
-		Reset()
-		Stop()
-	}
-
-	// A request handler.
-	// TODO (could make error more and return more info to user automatically?)
-	ServiceHandler func(svc Service, req *nats.Msg) error
-
-	// Clients can request as well.
-	ServiceStats struct {
-		Name      string    `json:"name"`
-		ID        string    `json:"id"`
-		Version   string    `json:"version"`
-		Started   time.Time `json:"started"`
-		Endpoints []Stats   `json:"stats"`
-	}
-
-	Stats struct {
-		Name           string        `json:"name"`
-		NumRequests    int           `json:"num_requests"`
-		NumErrors      int           `json:"num_errors"`
-		TotalLatency   time.Duration `json:"total_latency"`
-		AverageLatency time.Duration `json:"average_latency"`
-		Data           interface{}   `json:"data"`
-	}
-
-	// ServiceInfo is the basic information about a service type
-	ServiceInfo struct {
-		Name        string `json:"name"`
-		ID          string `json:"id"`
-		Description string `json:"description"`
-		Version     string `json:"version"`
-		Subject     string `json:"subject"`
-	}
-
-	ServiceSchema struct {
-		Request  string `json:"request"`
-		Response string `json:"response"`
-	}
-
-	Endpoint struct {
-		Subject string `json:"subject"`
-		Handler ServiceHandler
-	}
-
-	InternalEndpoint struct {
-		Name    string
-		Handler nats.MsgHandler
-	}
-
-	ServiceVerb int64
-
-	ServiceConfig struct {
-		Name          string        `json:"name"`
-		Description   string        `json:"description"`
-		Version       string        `json:"version"`
-		Schema        ServiceSchema `json:"schema"`
-		Endpoint      Endpoint      `json:"endpoint"`
-		StatusHandler func(Endpoint) interface{}
-	}
-
-	// service is the internal implementation of a Service
-	service struct {
-		sync.Mutex
-		ServiceConfig
-		id string
-		// subs
-		reqSub   *nats.Subscription
-		internal map[string]*nats.Subscription
-		statuses map[string]*Stats
-		stats    *ServiceStats
-		conn     *nats.Conn
-	}
-)
-
-const (
-	// We can fix this, as versions will be on separate subjects and use account mapping to roll requests to new versions etc.
-	QG = "svc"
-
-	// ServiceApiPrefix is the root of all control subjects
-	ServiceApiPrefix = "$SRV"
-
-	ServiceErrorHeader = "Nats-Service-Error"
-)
-
-const (
-	SrvPing ServiceVerb = iota
-	SrvStatus
-	SrvInfo
-	SrvSchema
-)
-
-func (s *ServiceConfig) Valid() error {
-	if s.Name == "" {
-		return errors.New("name is required")
-	}
-	return s.Endpoint.Valid()
-}
-
-func (e *Endpoint) Valid() error {
-	s := strings.TrimSpace(e.Subject)
-	if len(s) == 0 {
-		return errors.New("subject is required")
-	}
-	if e.Handler == nil {
-		return errors.New("handler is required")
-	}
-	return nil
-}
-
-func (s ServiceVerb) String() string {
-	switch s {
-	case SrvPing:
-		return "PING"
-	case SrvStatus:
-		return "STATUS"
-	case SrvInfo:
-		return "INFO"
-	case SrvSchema:
-		return "SCHEMA"
-	default:
-		return ""
-	}
-}
-
-// Add adds a microservice.
-// NOTE we can do an OpenAPI version as well, but looking at it it was very involved. So I think keep simple version and
-// also have a version that talkes full blown OpenAPI spec and we can pull these things out.
-func Add(nc *nats.Conn, config ServiceConfig) (Service, error) {
-	if err := config.Valid(); err != nil {
-		return nil, err
-	}
-
-	id := nuid.Next()
-	svc := &service{
-		ServiceConfig: config,
-		conn:          nc,
-		id:            id,
-	}
-	svc.internal = make(map[string]*nats.Subscription)
-	svc.statuses = make(map[string]*Stats)
-	svc.statuses[""] = &Stats{
-		Name: config.Name,
-	}
-
-	svc.stats = &ServiceStats{
-		Name:    config.Name,
-		ID:      id,
-		Version: config.Version,
-		Started: time.Now(),
-	}
-
-	// Setup internal subscriptions.
-	var err error
-
-	svc.reqSub, err = nc.QueueSubscribe(config.Endpoint.Subject, QG, func(m *nats.Msg) {
-		svc.reqHandler(m)
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	info := &ServiceInfo{
-		Name:        config.Name,
-		ID:          id,
-		Description: config.Description,
-		Version:     config.Version,
-		Subject:     config.Endpoint.Subject,
-	}
-
-	infoHandler := func(m *nats.Msg) {
-		response, _ := json.MarshalIndent(info, "", "  ")
-		m.Respond(response)
-	}
-
-	pingHandler := func(m *nats.Msg) {
-		infoHandler(m)
-	}
-
-	statusHandler := func(m *nats.Msg) {
-		response, _ := json.MarshalIndent(svc.Stats(), "", "  ")
-		m.Respond(response)
-	}
-
-	schemaHandler := func(m *nats.Msg) {
-		response, _ := json.MarshalIndent(svc.ServiceConfig.Schema, "", "  ")
-		m.Respond(response)
-	}
-
-	if err := svc.addInternalHandlerGroup(nc, SrvInfo, infoHandler); err != nil {
-		return nil, err
-	}
-	if err := svc.addInternalHandlerGroup(nc, SrvPing, pingHandler); err != nil {
-		return nil, err
-	}
-	if err := svc.addInternalHandlerGroup(nc, SrvStatus, statusHandler); err != nil {
-		return nil, err
-	}
-
-	if svc.ServiceConfig.Schema.Request != "" || svc.ServiceConfig.Schema.Response != "" {
-		if err := svc.addInternalHandlerGroup(nc, SrvSchema, schemaHandler); err != nil {
-			return nil, err
-		}
-	}
-
-	svc.stats.ID = id
-	svc.stats.Started = time.Now()
-	return svc, nil
-}
-
-// addInternalHandlerGroup generates control handlers for a specific verb
-// each request generates 3 subscriptions, one for the general verb
-// affecting all services written with the framework, one that handles
-// all services of a particular kind, and finally a specific service.
-func (svc *service) addInternalHandlerGroup(nc *nats.Conn, verb ServiceVerb, handler nats.MsgHandler) error {
-	name := fmt.Sprintf("%s-all", verb.String())
-	if err := svc.addInternalHandler(nc, verb, "", "", name, handler); err != nil {
-		return err
-	}
-	name = fmt.Sprintf("%s-kind", verb.String())
-	if err := svc.addInternalHandler(nc, verb, svc.Name(), "", name, handler); err != nil {
-		return err
-	}
-	return svc.addInternalHandler(nc, verb, svc.Name(), svc.ID(), verb.String(), handler)
-}
-
-// addInternalHandler registers a control subject handler
-func (svc *service) addInternalHandler(nc *nats.Conn, verb ServiceVerb, kind, id, name string, handler nats.MsgHandler) error {
-	subj, err := SvcControlSubject(verb, kind, id)
-	if err != nil {
-		svc.Stop()
-		return err
-	}
-
-	svc.internal[name], err = nc.Subscribe(subj, func(msg *nats.Msg) {
-		start := time.Now()
-		defer func() {
-			svc.Lock()
-			stats := svc.statuses[name]
-			stats.NumRequests++
-			stats.TotalLatency += time.Since(start)
-			stats.AverageLatency = stats.TotalLatency / time.Duration(stats.NumRequests)
-			svc.Unlock()
-		}()
-		handler(msg)
-	})
-	if err != nil {
-		svc.Stop()
-		return err
-	}
-
-	svc.statuses[name] = &Stats{
-		Name: name,
-	}
-	return nil
-}
-
-// reqHandler itself
-func (svc *service) reqHandler(req *nats.Msg) {
-	start := time.Now()
-	defer func() {
-		svc.Lock()
-		stats := svc.statuses[""]
-		stats.NumRequests++
-		stats.TotalLatency += time.Since(start)
-		stats.AverageLatency = stats.TotalLatency / time.Duration(stats.NumRequests)
-		svc.Unlock()
-	}()
-
-	if err := svc.ServiceConfig.Endpoint.Handler(svc, req); err != nil {
-		hdr := make(nats.Header)
-		apiErr := &ServiceAPIError{}
-		if ok := errors.As(err, &apiErr); !ok {
-			hdr[ServiceErrorHeader] = []string{fmt.Sprintf("%d %s", 500, err.Error())}
-		} else {
-			hdr[ServiceErrorHeader] = []string{apiErr.Error()}
-		}
-		svc.Lock()
-		stats := svc.statuses[""]
-		stats.NumErrors++
-		svc.Unlock()
-
-		svc.conn.PublishMsg(&nats.Msg{
-			Subject: req.Reply,
-			Header:  hdr,
-		})
-	}
-}
-
-func (svc *service) Stop() {
-	if svc.reqSub != nil {
-		svc.reqSub.Drain()
-		svc.reqSub = nil
-	}
-	var keys []string
-	for key, sub := range svc.internal {
-		keys = append(keys, key)
-		sub.Drain()
-	}
-	for _, key := range keys {
-		delete(svc.internal, key)
-	}
-}
-
-func (svc *service) ID() string {
-	return svc.id
-}
-
-func (svc *service) Name() string {
-	return svc.ServiceConfig.Name
-}
-
-func (svc *service) Description() string {
-	return svc.ServiceConfig.Description
-}
-
-func (svc *service) Version() string {
-	return svc.ServiceConfig.Version
-}
-
-func (svc *service) Stats() ServiceStats {
-	svc.Lock()
-	defer func() {
-		svc.Unlock()
-	}()
-	if svc.ServiceConfig.StatusHandler != nil {
-		stats := svc.statuses[""]
-		stats.Data = svc.ServiceConfig.StatusHandler(svc.Endpoint)
-	}
-	idx := 0
-	v := make([]Stats, len(svc.statuses))
-	for _, se := range svc.statuses {
-		v[idx] = *se
-		idx++
-	}
-	svc.stats.Endpoints = v
-	return *svc.stats
-}
-
-func (svc *service) Reset() {
-	for _, se := range svc.statuses {
-		se.NumRequests = 0
-		se.TotalLatency = 0
-		se.NumErrors = 0
-		se.Data = nil
-	}
-}
-
-// SvcControlSubject returns monitoring subjects used by the ServiceImpl
-func SvcControlSubject(verb ServiceVerb, kind, id string) (string, error) {
-	sverb := verb.String()
-	if sverb == "" {
-		return "", fmt.Errorf("unsupported service verb")
-	}
-	kind = strings.ToUpper(kind)
-	if kind == "" && id == "" {
-		return fmt.Sprintf("%s.%s", ServiceApiPrefix, sverb), nil
-	}
-	if id == "" {
-		return fmt.Sprintf("%s.%s.%s", ServiceApiPrefix, sverb, kind), nil
-	}
-	return fmt.Sprintf("%s.%s.%s.%s", ServiceApiPrefix, sverb, kind, id), nil
-}

services/service_test.go

@@ -1,260 +0,0 @@
-// Copyright 2022 The NATS Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package services
-
-import (
-	"encoding/json"
-	"fmt"
-	"math/rand"
-	"testing"
-	"time"
-
-	"github.com/nats-io/nats-server/v2/server"
-	natsserver "github.com/nats-io/nats-server/v2/test"
-	"github.com/nats-io/nats.go"
-)
-
-func TestServiceBasics(t *testing.T) {
-	s := RunServerOnPort(-1)
-	defer s.Shutdown()
-
-	nc, err := nats.Connect(s.ClientURL())
-	if err != nil {
-		t.Fatalf("Expected to connect to server, got %v", err)
-	}
-	defer nc.Close()
-
-	// Stub service.
-	doAdd := func(svc Service, req *nats.Msg) error {
-		if rand.Intn(10) == 0 {
-			return fmt.Errorf("Unexpected Error!")
-		}
-		// Happy Path.
-		// Random delay between 5-10ms
-		time.Sleep(5*time.Millisecond + time.Duration(rand.Intn(5))*time.Millisecond)
-		if err := req.Respond([]byte("42")); err != nil {
-			return err
-		}
-		return nil
-	}
-
-	var svcs []Service
-
-	// Create 5 service responders.
-	config := ServiceConfig{
-		Name:        "CoolAddService",
-		Version:     "v0.1",
-		Description: "Add things together",
-		Endpoint: Endpoint{
-			Subject: "svc.add",
-			Handler: doAdd,
-		},
-		Schema: ServiceSchema{Request: "", Response: ""},
-	}
-
-	for i := 0; i < 5; i++ {
-		svc, err := Add(nc, config)
-		if err != nil {
-			t.Fatalf("Expected to create Service, got %v", err)
-		}
-		defer svc.Stop()
-		svcs = append(svcs, svc)
-	}
-
-	// Now send 50 requests.
-	for i := 0; i < 50; i++ {
-		_, err := nc.Request("svc.add", []byte(`{ "x": 22, "y": 11 }`), time.Second)
-		if err != nil {
-			t.Fatalf("Expected a response, got %v", err)
-		}
-	}
-
-	for _, svc := range svcs {
-		if svc.Name() != "CoolAddService" {
-			t.Fatalf("Expected %q, got %q", "CoolAddService", svc.Name())
-		}
-		if len(svc.Description()) == 0 || len(svc.Version()) == 0 {
-			t.Fatalf("Expected non empty description and version")
-		}
-	}
-
-	// Make sure we can request info, 1 response.
-	// This could be exported as well as main ServiceImpl.
-	subj, err := SvcControlSubject(SrvInfo, "CoolAddService", "")
-	if err != nil {
-		t.Fatalf("Failed to building info subject %v", err)
-	}
-	info, err := nc.Request(subj, nil, time.Second)
-	if err != nil {
-		t.Fatalf("Expected a response, got %v", err)
-	}
-	var inf ServiceInfo
-	if err := json.Unmarshal(info.Data, &inf); err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-	if inf.Subject != "svc.add" {
-		t.Fatalf("expected service subject to be srv.add: %s", inf.Subject)
-	}
-
-	// Ping all services. Multiple responses.
-	// could do STATZ too?
-	inbox := nats.NewInbox()
-	sub, err := nc.SubscribeSync(inbox)
-	if err != nil {
-		t.Fatalf("subscribe failed: %s", err)
-	}
-	pingSubject, err := SvcControlSubject(SrvPing, "CoolAddService", "")
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-	if err := nc.PublishRequest(pingSubject, inbox, nil); err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-
-	var pingCount int
-	for {
-		_, err := sub.NextMsg(250 * time.Millisecond)
-		if err != nil {
-			break
-		}
-		pingCount++
-	}
-	if pingCount != 5 {
-		t.Fatalf("Expected 5 ping responses, got: %d", pingCount)
-	}
-
-	// Get stats from all services
-	statsInbox := nats.NewInbox()
-	sub, err = nc.SubscribeSync(statsInbox)
-	if err != nil {
-		t.Fatalf("subscribe failed: %s", err)
-	}
-	statsSubject, err := SvcControlSubject(SrvStatus, "CoolAddService", "")
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-	if err := nc.PublishRequest(statsSubject, statsInbox, nil); err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
-
-	stats := make([]ServiceStats, 0)
-	var requestsNum int
-	for {
-		resp, err := sub.NextMsg(250 * time.Millisecond)
-		if err != nil {
-			break
-		}
-		var srvStats ServiceStats
-		if err := json.Unmarshal(resp.Data, &srvStats); err != nil {
-			t.Fatalf("Unexpected error: %v", err)
-		}
-		if len(srvStats.Endpoints) != 10 {
-			t.Fatalf("Expected 10 endpoints on a serivce, got: %d", len(srvStats.Endpoints))
-		}
-		for _, e := range srvStats.Endpoints {
-			if e.Name == "CoolAddService" {
-				requestsNum += e.NumRequests
-			}
-		}
-		stats = append(stats, srvStats)
-	}
-	if len(stats) != 5 {
-		t.Fatalf("Expected stats for 5 services, got: %d", len(stats))
-	}
-
-	// Services should process 50 requests total
-	if requestsNum != 50 {
-		t.Fatalf("Expected a total fo 50 requests processed, got: %d", requestsNum)
-	}
-}
-
-func TestServiceErrors(t *testing.T) {
-	tests := []struct {
-		name            string
-		handlerResponse error
-		expectedStatus  string
-	}{
-		{
-			name:            "generic error",
-			handlerResponse: fmt.Errorf("oops"),
-			expectedStatus:  "500 oops",
-		},
-		{
-			name:            "api error",
-			handlerResponse: &ServiceAPIError{ErrorCode: 400, Description: "oops"},
-			expectedStatus:  "400 oops",
-		},
-		{
-			name:            "no error",
-			handlerResponse: nil,
-			expectedStatus:  "",
-		},
-	}
-
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
-			s := RunServerOnPort(-1)
-			defer s.Shutdown()
-
-			nc, err := nats.Connect(s.ClientURL())
-			if err != nil {
-				t.Fatalf("Expected to connect to server, got %v", err)
-			}
-			defer nc.Close()
-
-			// Stub service.
-			handler := func(svc Service, req *nats.Msg) error {
-				if test.handlerResponse == nil {
-					if err := req.Respond([]byte("ok")); err != nil {
-						return err
-					}
-				}
-				return test.handlerResponse
-			}
-
-			svc, err := Add(nc, ServiceConfig{
-				Name:        "CoolService",
-				Description: "Erroring service",
-				Endpoint: Endpoint{
-					Subject: "svc.fail",
-					Handler: handler,
-				},
-			})
-			if err != nil {
-				t.Fatalf("Unexpected error: %v", err)
-			}
-			defer svc.Stop()
-
-			resp, err := nc.Request("svc.fail", nil, 1*time.Second)
-			if err != nil {
-				t.Fatalf("request error")
-			}
-
-			status := resp.Header.Get("Nats-Service-Error")
-			if status != test.expectedStatus {
-				t.Fatalf("Invalid response status; want: %q; got: %q", test.expectedStatus, status)
-			}
-		})
-	}
-}
-
-func RunServerOnPort(port int) *server.Server {
-	opts := natsserver.DefaultTestOptions
-	opts.Port = port
-	return RunServerWithOptions(&opts)
-}
-
-func RunServerWithOptions(opts *server.Options) *server.Server {
-	return natsserver.RunServer(opts)
-}

timer.go

@@ -1,4 +1,4 @@
-// Copyright 2017-2018 The NATS Authors
+// Copyright 2017-2022 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

timer_test.go

@@ -1,4 +1,4 @@
-// Copyright 2017-2018 The NATS Authors
+// Copyright 2017-2022 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

ws.go

@@ -1,4 +1,4 @@
-// Copyright 2021 The NATS Authors
+// Copyright 2021-2022 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at

ws_test.go

@@ -1,4 +1,4 @@
-// Copyright 2021 The NATS Authors
+// Copyright 2021-2022 The NATS Authors
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at