docs(codec): remove factory from ProtoCodec (#108)

* docs(codec): switch ProtoCodec docs from factory to prototype

Update README and docs to reflect the new `NewProtoCodec[T, U](prototype T)`
constructor signature, replacing references to `ProtoRequestFactory` and factory
functions with a non-nil request prototype example.

This aligns documentation with current API behavior and clarifies that the
prototype is used to allocate fresh request messages for unmarshaling without
reflection.docs(codec): switch ProtoCodec docs from factory to prototype

Update README and docs to reflect the new `NewProtoCodec[T, U](prototype T)`
constructor signature, replacing references to `ProtoRequestFactory` and factory
functions with a non-nil request prototype example.

This aligns documentation with current API behavior and clarifies that the
prototype is used to allocate fresh request messages for unmarshaling without
reflection.

* feat(codec)!: remove prototype arg from NewProtoCodec

Simplify `ProtoCodec` construction by inferring the request message type from
generic `T` instead of requiring a non-nil prototype parameter. This reduces
boilerplate while still allowing fresh request allocation without reflection.

Also update README/docs/examples to reflect the new API and bump GitHub Actions
Go versions to `1.26.1` for tests, linting, benchmarks, and example builds.

BREAKING CHANGE: `codec.NewProtoCodec[T, U](prototype T)` is now
`codec.NewProtoCodec[T, U]()`.feat(codec)!: remove prototype arg from NewProtoCodec

Simplify `ProtoCodec` construction by inferring the request message type from
generic `T` instead of requiring a non-nil prototype parameter. This reduces
boilerplate while still allowing fresh request allocation without reflection.

Also update README/docs/examples to reflect the new API and bump GitHub Actions
Go versions to `1.26.1` for tests, linting, benchmarks, and example builds.

BREAKING CHANGE: `codec.NewProtoCodec[T, U](prototype T)` is now
`codec.NewProtoCodec[T, U]()`.

Author: Suhaibinator

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: ['1.24']
+        go-version: ['1.26.1']
         os: [ubuntu-latest, macos-latest, windows-latest]
       fail-fast: true
 
@@ -60,7 +60,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.24'
+        go-version: '1.26.1'
         cache: true
 
     - name: Install golangci-lint
@@ -74,7 +74,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: ['1.24']
+        go-version: ['1.26.1']
         os: [ubuntu-latest, macos-latest, windows-latest]
 
     steps:
@@ -100,7 +100,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.24'
+        go-version: '1.26.1'
         cache: true
 
     - name: Run benchmarks
@@ -116,7 +116,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.24'
+        go-version: '1.26.1'
         cache: true
 
     - name: Build simple example

README.md

@@ -1411,14 +1411,10 @@ codec.NewJSONCodec[T, U]() *codec.JSONCodec[T, U]
 
 ### ProtoCodec
 
-Uses Protocol Buffers for marshaling and unmarshaling. Requires a factory function to create new request message instances without reflection.
+Uses Protocol Buffers for marshaling and unmarshaling. It allocates fresh request messages without reflection.
 
 ```go
-// Define a factory function for your specific proto message type (e.g., *MyProto)
-myProtoFactory := func() *pb.MyProto { return &pb.MyProto{} } // Use generated type
-
-// Pass the factory to the constructor
-codec.NewProtoCodec[T, U](myProtoFactory) *codec.ProtoCodec[T, U] // T must match factory return type
+codec.NewProtoCodec[T, U]() *codec.ProtoCodec[T, U]
 ```
 
 ### Codec Interface

docs/codecs.md

@@ -60,23 +60,17 @@ route := router.RouteConfig[MyRequest, MyResponse]{
 
 Handles Protocol Buffers encoding and decoding using Google's `protobuf` libraries (e.g., `google.golang.org/protobuf/proto`).
 
-**Important:** Due to the nature of Protocol Buffers, the `ProtoCodec` requires a factory function (`codec.ProtoRequestFactory`) when being constructed. This function must return a new, zero-value instance of the specific *request* proto message type (`T`). This is needed internally to provide a concrete type for unmarshaling without relying on reflection.
+**Important:** `ProtoCodec` infers the concrete request message type from `T`, so it can allocate fresh zero-value messages for unmarshaling without reflection.
 
 ```go
 import (
 	"github.com/Suhaibinator/SRouter/pkg/codec"
 	pb "path/to/your/generated/proto/package" // Import your generated proto package
 )
 
-// Define the factory function for your request proto message type
-// It must return the specific pointer type (e.g., *pb.MyRequestProto)
-var myRequestFactory = func() *pb.MyRequestProto {
-	return &pb.MyRequestProto{}
-}
-
-// Create a new Proto codec, providing the factory function
+// Create a new Proto codec.
 // T is *pb.MyRequestProto, U is *pb.MyResponseProto (or appropriate response type)
-protoCodec := codec.NewProtoCodec[*pb.MyRequestProto, *pb.MyResponseProto](myRequestFactory)
+protoCodec := codec.NewProtoCodec[*pb.MyRequestProto, *pb.MyResponseProto]()
 
 
 // Use it in RouteConfig
@@ -193,6 +187,6 @@ Remember to handle errors appropriately within your codec methods, potentially r
 
 -   **`codec.Codec[T, U]`**: Interface defining methods `NewRequest() T`, `Decode(*http.Request) (T, error)`, `DecodeBytes([]byte) (T, error)`, and `Encode(http.ResponseWriter, U) error`.
 -   **`codec.NewJSONCodec[T, U]() *codec.JSONCodec[T, U]`**: Constructor for the built-in JSON codec.
--   **`codec.NewProtoCodec[T, U](factory codec.ProtoRequestFactory[T]) *codec.ProtoCodec[T, U]`**: Constructor for the built-in Protocol Buffers codec, requiring a factory function for the request type `T`.
+-   **`codec.NewProtoCodec[T, U]() *codec.ProtoCodec[T, U]`**: Constructor for the built-in Protocol Buffers codec.
 
 See the `examples/codec` directory for runnable examples using different codecs.

docs/examples.md

@@ -26,7 +26,7 @@ Here's a brief overview of the available examples (refer to the source code and
 -   **`/examples/trace-logging`**: Demonstrates enabling and using trace IDs for correlating logs within a request lifecycle.
 -   **`/examples/cors-error-test`**: Demonstrates handling CORS preflight and error scenarios, including how SRouter writes CORS headers on error responses.
 -   **`/examples/source-types`**: Shows how to use different `SourceType` options (Body, Base64QueryParameter, Base64PathParameter, etc.) for generic routes.
--   **`/examples/codec`**: Illustrates using different codecs, particularly `JSONCodec` and `ProtoCodec` (including the required factory function for proto).
+-   **`/examples/codec`**: Illustrates using different codecs, particularly `JSONCodec` and `ProtoCodec`.
 -   **`/examples/prometheus`**: Example of integrating SRouter's metrics system with Prometheus by providing a Prometheus-based implementation of the `metrics.MetricsRegistry` interface and showing how the application can expose the metrics via an HTTP handler.
 -   **`/examples/custom-metrics`**: Demonstrates implementing a custom `metrics.MetricsRegistry` or `metrics.MetricsMiddleware`.
 -   **`/examples/handler-error-middleware`**: Shows how middleware can access errors returned by generic handlers to make decisions (e.g., transaction rollback, custom error logging) using `scontext.GetHandlerErrorFromRequest`.

examples/codec/main.go

@@ -65,10 +65,7 @@ func main() {
 	}, placeholderAuth, placeholderGetUserID)
 
 	// Instantiate the ProtoCodec (can be done once outside the handler if reused)
-	// Create a factory function for User messages
-	userFactory := func() *pb.User { return &pb.User{} }
-	// Create a ProtoCodec for User messages, providing the factory
-	protoCodec := codec.NewProtoCodec[*pb.User, *pb.User](userFactory)
+	protoCodec := codec.NewProtoCodec[*pb.User, *pb.User]()
 
 	// Define the generic route configuration
 	routeCfg := router.RouteConfig[*pb.User, *pb.User]{

go.mod

@@ -1,6 +1,6 @@
 module github.com/Suhaibinator/SRouter
 
-go 1.24.0
+go 1.26.0
 
 require (
 	github.com/julienschmidt/httprouter v1.3.0
@@ -19,8 +19,8 @@ require (
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	go.yaml.in/yaml/v2 v2.4.3 // indirect
-	golang.org/x/text v0.32.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.4 // indirect
+	golang.org/x/text v0.34.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
@@ -30,10 +30,10 @@ require (
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/prometheus/client_model v0.6.2
-	github.com/prometheus/common v0.67.4 // indirect
-	github.com/prometheus/procfs v0.19.2 // indirect
+	github.com/prometheus/common v0.67.5 // indirect
+	github.com/prometheus/procfs v0.20.1 // indirect
 	go.uber.org/ratelimit v0.3.1
-	golang.org/x/sys v0.39.0 // indirect
+	golang.org/x/sys v0.42.0 // indirect
 	google.golang.org/protobuf v1.36.11
 )
 

go.sum

@@ -34,10 +34,10 @@ github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h
 github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
 github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
 github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
-github.com/prometheus/common v0.67.4 h1:yR3NqWO1/UyO1w2PhUvXlGQs/PtFmoveVO0KZ4+Lvsc=
-github.com/prometheus/common v0.67.4/go.mod h1:gP0fq6YjjNCLssJCQp0yk4M8W6ikLURwkdd/YKtTbyI=
-github.com/prometheus/procfs v0.19.2 h1:zUMhqEW66Ex7OXIiDkll3tl9a1ZdilUOd/F6ZXw4Vws=
-github.com/prometheus/procfs v0.19.2/go.mod h1:M0aotyiemPhBCM0z5w87kL22CxfcH05ZpYlu+b4J7mw=
+github.com/prometheus/common v0.67.5 h1:pIgK94WWlQt1WLwAC5j2ynLaBRDiinoAb86HZHTUGI4=
+github.com/prometheus/common v0.67.5/go.mod h1:SjE/0MzDEEAyrdr5Gqc6G+sXI67maCxzaT3A2+HqjUw=
+github.com/prometheus/procfs v0.20.1 h1:XwbrGOIplXW/AU3YhIhLODXMJYyC1isLFfYCsTEycfc=
+github.com/prometheus/procfs v0.20.1/go.mod h1:o9EMBZGRyvDrSPH1RqdxhojkuXstoe4UlK79eF5TGGo=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
@@ -52,12 +52,12 @@ go.uber.org/ratelimit v0.3.1 h1:K4qVE+byfv/B3tC+4nYWP7v/6SimcO7HzHekoMNBma0=
 go.uber.org/ratelimit v0.3.1/go.mod h1:6euWsTB6U/Nb3X++xEUXA8ciPJvr19Q/0h1+oDcJhRk=
 go.uber.org/zap v1.27.1 h1:08RqriUEv8+ArZRYSTXy1LeBScaMpVSTBhCeaZYfMYc=
 go.uber.org/zap v1.27.1/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=
-go.yaml.in/yaml/v2 v2.4.3 h1:6gvOSjQoTB3vt1l+CU+tSyi/HOjfOjRLJ4YwYZGwRO0=
-go.yaml.in/yaml/v2 v2.4.3/go.mod h1:zSxWcmIDjOzPXpjlTTbAsKokqkDNAVtZO0WOMiT90s8=
-golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
-golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
-golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
-golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
+go.yaml.in/yaml/v2 v2.4.4 h1:tuyd0P+2Ont/d6e2rl3be67goVK4R6deVxCUX5vyPaQ=
+go.yaml.in/yaml/v2 v2.4.4/go.mod h1:gMZqIpDtDqOfM0uNfy0SkpRhvUryYH0Z6wdMYcacYXQ=
+golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
+golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
+golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

pkg/codec/proto.go

@@ -8,41 +8,39 @@ import (
 	"google.golang.org/protobuf/proto"
 )
 
-// ProtoRequestFactory is a function type that creates new instances of protobuf request messages.
-// It returns a pointer to a type implementing proto.Message. This factory pattern is used
-// to avoid reflection when creating new message instances for decoding.
-// T must be a pointer type (e.g., *MyRequest) that implements proto.Message.
-type ProtoRequestFactory[T proto.Message] func() T
-
 // ProtoCodec implements the Codec interface for Protocol Buffers.
 // It handles marshaling and unmarshaling of protobuf messages for use with generic routes.
 // Both T and U must be pointer types that implement proto.Message (e.g., *MyRequest, *MyResponse).
 type ProtoCodec[T proto.Message, U proto.Message] struct {
-	// Factory function to create new request objects without reflection.
-	newRequest ProtoRequestFactory[T]
+	newRequest func() T
 }
 
-// NewProtoCodec creates a new ProtoCodec instance with the provided request factory.
-// The factory function is used to create new instances of the request type without reflection.
+// NewProtoCodec creates a new ProtoCodec instance for protobuf request/response types.
+// It infers the underlying message type from T and allocates fresh zero-value messages
+// without reflection by using Go's new(expr) support.
 //
 // Example:
 //
-//	codec := NewProtoCodec[*pb.CreateUserReq, *pb.CreateUserResp](func() *pb.CreateUserReq {
-//	    return &pb.CreateUserReq{}
-//	})
-func NewProtoCodec[T proto.Message, U proto.Message](factory ProtoRequestFactory[T]) *ProtoCodec[T, U] {
+//	codec := NewProtoCodec[*pb.CreateUserReq, *pb.CreateUserResp]()
+func NewProtoCodec[T interface {
+	proto.Message
+	*M
+}, U proto.Message, M any]() *ProtoCodec[T, U] {
+
+	var zero M
 	return &ProtoCodec[T, U]{
-		newRequest: factory,
+		newRequest: func() T {
+			return new(zero)
+		},
 	}
 }
 
 // For testing purposes, we expose these variables so they can be overridden in tests
 var protoUnmarshal = proto.Unmarshal
 var protoMarshal = proto.Marshal
 
-// NewRequest creates a new instance of the request protobuf message using the factory.
-// It implements the Codec interface. The factory pattern avoids the need for reflection
-// when creating new message instances.
+// NewRequest creates a new instance of the request protobuf message.
+// It implements the Codec interface.
 func (c *ProtoCodec[T, U]) NewRequest() T {
 	return c.newRequest()
 }
@@ -52,7 +50,7 @@ func (c *ProtoCodec[T, U]) NewRequest() T {
 // body is closed after reading. Returns an error if the data is not valid protobuf
 // or doesn't match the expected message type.
 func (c *ProtoCodec[T, U]) Decode(r *http.Request) (T, error) {
-	msg := c.NewRequest() // Use the factory to create a new message instance
+	msg := c.NewRequest()
 
 	body, err := io.ReadAll(r.Body)
 	if err != nil {
@@ -73,7 +71,7 @@ func (c *ProtoCodec[T, U]) Decode(r *http.Request) (T, error) {
 // data comes from sources other than the request body (e.g., base64-encoded
 // query parameters). Returns an error if the data is invalid.
 func (c *ProtoCodec[T, U]) DecodeBytes(data []byte) (T, error) {
-	msg := c.NewRequest() // Use the factory to create a new message instance
+	msg := c.NewRequest()
 
 	// Unmarshal directly from the provided data
 	if err := protoUnmarshal(data, msg); err != nil {
@@ -96,5 +94,3 @@ func (c *ProtoCodec[T, U]) Encode(w http.ResponseWriter, resp U) error {
 	_, err = w.Write(bytes)
 	return err
 }
-
-// newMessage function is removed as it's replaced by the factory approach.

pkg/codec/proto_test.go

@@ -21,26 +21,30 @@ func (m *TestProtoMessage) String() string                     { return string(m
 func (m *TestProtoMessage) ProtoMessage()                      {}
 func (m *TestProtoMessage) ProtoReflect() protoreflect.Message { return nil }
 
-// testProtoFactory creates a new TestProtoMessage instance.
-func testProtoFactory() *TestProtoMessage {
-	return &TestProtoMessage{}
-}
-
 // TestNewProtoCodec tests the NewProtoCodec function
 func TestNewProtoCodec(t *testing.T) {
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 	if codec == nil {
 		t.Error("Expected non-nil codec")
 	}
 	if codec == nil || codec.newRequest == nil {
 		t.Error("Expected codec.newRequest to be set")
 	}
+
+	req := codec.NewRequest()
+	if req == nil {
+		t.Fatal("Expected NewRequest to allocate a message")
+	}
+
+	if req == codec.NewRequest() {
+		t.Error("Expected NewRequest to return a distinct message instance")
+	}
 }
 
 // TestProtoCodecDecode tests the Decode method of ProtoCodec
 func TestProtoCodecDecode(t *testing.T) {
 	// Create a codec
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 
 	// Create a request with test data
 	reqBody := []byte("test data")
@@ -81,7 +85,7 @@ func TestProtoCodecDecode(t *testing.T) {
 // TestProtoCodecEncode tests the Encode method of ProtoCodec
 func TestProtoCodecEncode(t *testing.T) {
 	// Create a codec
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 
 	// Create a mock implementation of proto.Marshal
 	originalMarshal := protoMarshal
@@ -125,7 +129,7 @@ func TestProtoCodecEncode(t *testing.T) {
 // TestProtoCodecDecodeBytes tests the DecodeBytes method of ProtoCodec
 func TestProtoCodecDecodeBytes(t *testing.T) {
 	// Create a codec
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 
 	// Test data (simulating decoded bytes from Base64/Base62)
 	testBytes := []byte("test byte data")
@@ -177,7 +181,7 @@ func TestProtoCodecDecodeBytes(t *testing.T) {
 // TestProtoCodecDecodeErrors tests error handling in the Decode method of ProtoCodec
 func TestProtoCodecDecodeErrors(t *testing.T) {
 	// Create a codec
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 
 	// Test Decode with read error
 	req := httptest.NewRequest("POST", "/test", &errorReader{})
@@ -209,7 +213,7 @@ func TestProtoCodecDecodeErrors(t *testing.T) {
 // TestProtoCodecEncodeErrors tests error handling in the Encode method of ProtoCodec
 func TestProtoCodecEncodeErrors(t *testing.T) {
 	// Create a codec
-	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage](testProtoFactory)
+	codec := NewProtoCodec[*TestProtoMessage, *TestProtoMessage]()
 
 	// Test Encode with marshal error
 	rr := httptest.NewRecorder()
@@ -241,5 +245,3 @@ func TestProtoCodecEncodeErrors(t *testing.T) {
 		t.Error("Expected error when writing response fails")
 	}
 }
-
-// TestNewMessage is removed as the newMessage function no longer exists.