Mm/refactoring/comments2

.golangci.yml

@@ -49,7 +49,7 @@ linters-settings:
       - golang.org/x/tools
       - gopkg.in/yaml.v2
       - github.com/alexflint/go-arg
-      - github.com/gorilla/websocket
+      - github.com/google/uuid
 
   forbidigo:
     forbid:

docs/CHANGELOG.md

@@ -26,7 +26,8 @@ When releasing a new version:
 
 - The new `optional: generic` allows using a generic type to represent optionality. See the [documentation](genqlient.yaml) for details.
 - For schemas with enum values that differ only in casing, it's now possible to disable smart-casing in genqlient.yaml; see the [documentation](genqlient.yaml) for `casing` for details.
-- genqlient now supports subscriptions
+- genqlient now supports subscriptions; the websocket protocol is by default `graphql-transport-ws` but can be set to another value.  
+  See the [documentation](FAQ.md) for how to `subscribe to an API 'subscription' endpoint`.
 
 ### Bug fixes:
 - The presence of negative pointer directives, i.e., `# @genqlient(pointer: false)` are now respected even in the when `optional: pointer` is set in the configuration file.

docs/FAQ.md

@@ -108,21 +108,26 @@ Once your webSocket client matches the interfaces, you can get your `graphql.Web
 a loop for incoming messages and errors:
 
 ```go
-graphqlClient := graphql.NewClientUsingWebSocket(
+  graphqlClient := graphql.NewClientUsingWebSocket(
 		"ws://localhost:8080/query",
 		&MyDialer{Dialer: dialer},
 		headers,
 	)
 
-	respChan, errChan, err := count(context.Background(), graphqlClient)
+	errChan, err := graphqlClient.StartWebSocket(ctx)
+	if err != nil {
+		return
+	}
+
+	dataChan, subscriptionID, err := count(ctx, graphqlClient)
 	if err != nil {
 		return
 	}
 
 	defer graphqlClient.CloseWebSocket()
 	for loop := true; loop; {
 		select {
-		case msg, more := <-respChan:
+		case msg, more := <-dataChan:
 			if !more {
 				loop = false
 				break
@@ -136,9 +141,16 @@ graphqlClient := graphql.NewClientUsingWebSocket(
 			}
 		case err = <-errChan:
 			return
+    case <-time.After(time.Minute):
+      err = wsClient.Unsubscribe(subscriptionID)
+      loop = false
 		}
 	}
 ```
+To change the websocket protocol from its default value `graphql-transport-ws`, add the following header before calling `graphql.NewClientUsingWebSocket()`:
+```go
+  headers.Add("Sec-WebSocket-Protocol", "graphql-ws")
+```
 
 ### … use an API that requires authentication?
 

generate/generate.go

@@ -282,7 +282,7 @@ func (g *generator) addOperation(op *ast.OperationDefinition) error {
 		docComment = "// " + strings.ReplaceAll(commentLines, "\n", "\n// ")
 	}
 	if op.Operation == ast.Subscription {
-		docComment += "\n// To close the connection, use [graphql.WebSocketClient.CloseWebSocket()]"
+		docComment += "\n// To unsubscribe, use [graphql.WebSocketClient.Unsubscribe]"
 	}
 
 	// If the filename is a pseudo-filename filename.go:startline, just

generate/operation.go.tmpl

@@ -15,7 +15,7 @@ func {{.Name}}(
     {{.GraphQLName}} {{.GoType.Reference}},
     {{end -}}
     {{end -}}
-) ({{if eq .Type "subscription"}}dataChan_ chan {{.Name}}WsResponse, errChan_ chan error,{{else}}data_ *{{.ResponseName}}, {{if .Config.Extensions -}}ext_ map[string]interface{},{{end}}{{end}} err_ error) {
+) ({{if eq .Type "subscription"}}dataChan_ chan {{.Name}}WsResponse, subscriptionID_ string,{{else}}data_ *{{.ResponseName}}, {{if .Config.Extensions -}}ext_ map[string]interface{},{{end}}{{end}} err_ error) {
     req_ := &graphql.Request{
         OpName: "{{.Name}}",
         Query:  {{.Name}}_Operation,
@@ -36,14 +36,8 @@ func {{.Name}}(
     }
     {{end}}
     {{if eq .Type "subscription"}}
-    dataChan_ = make(chan {{.Name}}WsResponse, 1)
-    respChan_ := make(chan json.RawMessage, 1)
-
-    errChan_, err_ = client_.DialWebSocket({{if ne .Config.ContextType "-" -}}ctx_{{else}}context.Background(){{end}}, req_, respChan_)
-	if err_ != nil {
-		return nil, nil, err_
-	}
-    go {{.Name}}ForwardData(dataChan_, respChan_, errChan_)
+    dataChan_ = make(chan {{.Name}}WsResponse)
+    subscriptionID_, err_ = client_.Subscribe(req_, dataChan_, {{.Name}}ForwardData)
     {{else}}
     data_ = &{{.ResponseName}}{}
     resp_ := &graphql.Response{Data: data_}
@@ -55,7 +49,7 @@ func {{.Name}}(
     )
     {{end}}
 
-    return {{if eq .Type "subscription"}}dataChan_, errChan_,{{else}}data_, {{if .Config.Extensions -}}resp_.Extensions,{{end -}}{{end}} err_
+    return {{if eq .Type "subscription"}}dataChan_, subscriptionID_,{{else}}data_, {{if .Config.Extensions -}}resp_.Extensions,{{end -}}{{end}} err_
 }
 
 {{if eq .Type "subscription"}}
@@ -65,30 +59,26 @@ type {{.Name}}WsResponse struct {
 	Errors     error                  `json:"errors"`
 }
 
-func {{.Name}}ForwardData(dataChan_ chan {{.Name}}WsResponse, respChan_ chan json.RawMessage, errChan_ chan error) {
-    defer close(dataChan_)
+func {{.Name}}ForwardData(interfaceChan interface{}, jsonRawMsg json.RawMessage) error {
     var gqlResp graphql.Response
 	var wsResp {{.Name}}WsResponse
-	for {
-		jsonRaw, more_ := <-respChan_
-		if !more_ {
-			return
-		}
-		err := json.Unmarshal(jsonRaw, &gqlResp)
-		if err != nil {
-			errChan_ <- err
-			return
-		}
-		if len(gqlResp.Errors) == 0 {
-			err = json.Unmarshal(jsonRaw, &wsResp)
-			if err != nil {
-				errChan_ <- err
-				return
-			}
-		} else {
-			wsResp.Errors = gqlResp.Errors
-		}
-		dataChan_ <- wsResp
+    err := json.Unmarshal(jsonRawMsg, &gqlResp)
+    if err != nil {
+        return err
+    }
+    if len(gqlResp.Errors) == 0 {
+        err = json.Unmarshal(jsonRawMsg, &wsResp)
+        if err != nil {
+            return err
+        }
+    } else {
+        wsResp.Errors = gqlResp.Errors
+    }
+    dataChan_, ok := interfaceChan.(chan {{.Name}}WsResponse)
+	if !ok {
+		return errors.New("failed to cast interface into 'chan {{.Name}}WsResponse'")
 	}
+	dataChan_ <- wsResp
+	return nil
 }
 {{end}}

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/99designs/gqlgen v0.17.35
 	github.com/alexflint/go-arg v1.4.2
 	github.com/bradleyjkemp/cupaloy/v2 v2.6.0
+	github.com/google/uuid v1.3.1
 	github.com/gorilla/websocket v1.5.0
 	github.com/stretchr/testify v1.8.2
 	github.com/vektah/gqlparser/v2 v2.5.8