Add client and server versions of generators (webrpc, schema and ridl…

… schema)

_examples/golang-basics/example.ridl

@@ -1,8 +1,7 @@
 webrpc = v1             # version of webrpc schema format (ridl or json)
 
 name = example          # name of your backend app
-version = v0.0.1        # version of your schema
-
+version = [email protected]        # version of your schema
 
 # user role
 # which defines which type of operations user can do
@@ -69,6 +68,8 @@ struct Version
   - webrpcVersion: string
   - schemaVersion: string
   - schemaHash: string
+  - clientGenVersion: GenVersions
+  - serverGenVersion: GenVersions
 
 struct ComplexType
   - meta: map<string,any>
@@ -81,6 +82,12 @@ struct ComplexType
   - mapOfUsers: map<string,User>
   - user: User
 
+struct GenVersions
+  - WebRPCGenVersion: string
+  - TmplTarget: string
+  - TmplVersion: string
+  - SchemaVersion: string
+
 error 500100 MissingArgument "missing argument"
 error 500101 InvalidUsername "invalid username"
 error 400100 MemoryFull      "system memory is full"

_examples/golang-basics/example_test.go

@@ -38,6 +38,14 @@ func TestStatus(t *testing.T) {
 	assert.NoError(t, err)
 }
 
+func TestVersion(t *testing.T) {
+	version, err := client.Version(context.Background())
+
+	assert.NoError(t, err)
+	assert.NotNil(t, version.ClientGenVersion)
+	assert.NotNil(t, version.ServerGenVersion)
+}
+
 func TestGetUser(t *testing.T) {
 	{
 		arg1 := map[string]string{"a": "1"}

_examples/golang-basics/main.go

@@ -48,10 +48,44 @@ func (rpc *ExampleServiceRPC) Status(ctx context.Context) (bool, error) {
 }
 
 func (rpc *ExampleServiceRPC) Version(ctx context.Context) (*Version, error) {
+	req := RequestFromContext(ctx)
+	writer := ResponseWriterFromContext(ctx)
+
+	if writer.Header().Get("Webrpc") == "" {
+		return nil, fmt.Errorf("server webrpc header is missing")
+	}
+
+	serverVersions, err := ParseWebRPCGenVersions(writer.Header().Get("Webrpc"))
+	if err != nil {
+		return nil, fmt.Errorf("parse server webrpc gen versions: %w", err)
+	}
+
+	var clientVersions *GenVersions
+	if req.Header.Get("Webrpc") != "" {
+		parsedVersions, err := ParseWebRPCGenVersions(req.Header.Get("Webrpc"))
+		if err != nil {
+			return nil, fmt.Errorf("parse client webrpc gen versions: %w", err)
+		}
+
+		clientVersions = &GenVersions{
+			WebRPCGenVersion: parsedVersions.WebRPCGenVersion,
+			TmplTarget:       parsedVersions.TmplTarget,
+			TmplVersion:      parsedVersions.TmplVersion,
+			SchemaVersion:    parsedVersions.SchemaVersion,
+		}
+	}
+
 	return &Version{
-		WebrpcVersion: WebRPCVersion(),
-		SchemaVersion: WebRPCSchemaVersion(),
-		SchemaHash:    WebRPCSchemaHash(),
+		WebrpcVersion:    WebRPCVersion(),
+		SchemaVersion:    WebRPCSchemaVersion(),
+		SchemaHash:       WebRPCSchemaHash(),
+		ClientGenVersion: clientVersions,
+		ServerGenVersion: &GenVersions{
+			WebRPCGenVersion: serverVersions.WebRPCGenVersion,
+			TmplTarget:       serverVersions.TmplTarget,
+			TmplVersion:      serverVersions.TmplVersion,
+			SchemaVersion:    serverVersions.SchemaVersion,
+		},
 	}, nil
 }
 

client.go.tmpl

@@ -208,6 +208,7 @@ func newRequest(ctx context.Context, url string, reqBody io.Reader, contentType
 	}
 	req.Header.Set("Accept", contentType)
 	req.Header.Set("Content-Type", contentType)
+	req.Header.Set("Webrpc", WebRPCHeader())
 	if headers, ok := HTTPRequestHeaders(ctx); ok {
 		for k := range headers {
 			for _, v := range headers[k] {

main.go.tmpl

@@ -96,6 +96,44 @@ func WebRPCSchemaHash() string {
 	return "{{.SchemaHash}}"
 }
 
+type WebRPCGenVersions struct {
+    WebRPCGenVersion string
+    TmplTarget string
+    TmplVersion string
+    SchemaVersion string
+}
+
+// WebRPCHeader
+// TmplVersion might be empty when generated from local template folder
+func WebRPCHeader() string {
+    return "webrpc@{{.WebrpcGenVersion}};{{.TmplTarget}}@{{ if eq .TmplVersion "" }}unknown{{ else }}{{.TmplVersion}}{{end}};{{.SchemaVersion}}"
+}
+
+func ParseWebRPCGenVersions(header string) (*WebRPCGenVersions, error) {
+    versions := strings.Split(header, ";")
+
+    if len(versions) != 3 {
+        return nil, fmt.Errorf("expected 3 parts while parsing webrpc header: %s", header)
+    }
+
+    _, webrpcGenVersion, ok := strings.Cut(versions[0], "@")
+    if !ok {
+        return nil, fmt.Errorf("webrpc gen version could not be parsed from: %s", header)
+    }
+
+    tmplTarget, tmplVersion, ok := strings.Cut(versions[1], "@")
+    if !ok {
+        return nil, fmt.Errorf("tmplTarget and tmplVersion could not be parsed from: %s", header)
+    }
+
+    return &WebRPCGenVersions{
+        WebRPCGenVersion: webrpcGenVersion,
+        TmplTarget: tmplTarget,
+        TmplVersion: tmplVersion,
+        SchemaVersion: versions[2],
+    }, nil
+}
+
 {{- printf "\n" -}}
 
 {{- if eq $opts.importTypesFrom "" }}

server.go.tmpl

@@ -37,6 +37,8 @@ func (s *{{$serviceName}}) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}()
 
+	w.Header().Set("Webrpc", WebRPCHeader())
+
 	ctx := r.Context()
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)