test(bench): add allocation benchmarks for client/transport/dispatch hot paths

Hermetic benchmarks (no network) covering Call encode+decode, webhook ServeHTTP body parse, and Router dispatch (command/regex/filter). Use Go 1.24+ b.Loop() idiom. .benchstats/baseline.txt pins the pre-optimisation numbers for benchstat comparisons.

.benchstats/baseline.txt

@@ -0,0 +1,19 @@
+goos: darwin
+goarch: arm64
+pkg: github.com/lukaszraczylo/go-telegram/client
+cpu: Apple M4 Max
+BenchmarkCall_BoolResponse-16      	 1875306	       633.9 ns/op	    1957 B/op	      18 allocs/op
+BenchmarkCall_StructResponse-16    	 1805024	       665.2 ns/op	    2005 B/op	      18 allocs/op
+BenchmarkEncodeJSONBody-16         	23345811	        51.55 ns/op	      96 B/op	       2 allocs/op
+BenchmarkDecodeResult_Bool-16      	23832240	        50.37 ns/op	      80 B/op	       2 allocs/op
+BenchmarkDecodeResult_Struct-16    	13511192	        92.64 ns/op	     144 B/op	       2 allocs/op
+
+pkg: github.com/lukaszraczylo/go-telegram/transport
+BenchmarkWebhook_ServeHTTP-16    	  465798	      2564 ns/op	   12707 B/op	      24 allocs/op
+
+pkg: github.com/lukaszraczylo/go-telegram/dispatch
+BenchmarkRouter_DispatchCommand-16      	 7303522	       152.7 ns/op	     416 B/op	       5 allocs/op
+BenchmarkRouter_DispatchTextRegex-16    	 6740305	       180.5 ns/op	     428 B/op	       5 allocs/op
+BenchmarkRouter_DispatchFilter-16       	39479149	        32.18 ns/op	      96 B/op	       2 allocs/op
+BenchmarkRouter_NewContext-16           	208260764	         5.790 ns/op	       0 B/op	       0 allocs/op
+BenchmarkExtractCommand-16              	12988816	        92.69 ns/op	       0 B/op	       0 allocs/op

client/call_bench_test.go

@@ -0,0 +1,94 @@
+package client
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"net/http"
+	"testing"
+)
+
+// stubDoer returns the same canned response body for every request. It
+// is intentionally minimal — testify mock has its own overhead that
+// would dominate the per-call cost we want to measure.
+type stubDoer struct{ body []byte }
+
+func (s *stubDoer) Do(_ *http.Request) (*http.Response, error) {
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Body:       io.NopCloser(bytes.NewReader(s.body)),
+		Header:     http.Header{},
+	}, nil
+}
+
+type benchSendReq struct {
+	ChatID int64  `json:"chat_id"`
+	Text   string `json:"text"`
+}
+
+type benchMsgResp struct {
+	MessageID int64  `json:"message_id"`
+	Date      int64  `json:"date"`
+	Text      string `json:"text"`
+}
+
+func BenchmarkCall_BoolResponse(b *testing.B) {
+	d := &stubDoer{body: []byte(`{"ok":true,"result":true}`)}
+	bot := New("123:abc", WithHTTPClient(d))
+	ctx := context.Background()
+	req := &benchSendReq{ChatID: 42, Text: "hi"}
+	b.ReportAllocs()
+	for b.Loop() {
+		if _, err := Call[*benchSendReq, bool](ctx, bot, "setMyCommands", req); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkCall_StructResponse(b *testing.B) {
+	d := &stubDoer{body: []byte(`{"ok":true,"result":{"message_id":1,"date":0,"text":"ok"}}`)}
+	bot := New("123:abc", WithHTTPClient(d))
+	ctx := context.Background()
+	req := &benchSendReq{ChatID: 42, Text: "hi"}
+	b.ReportAllocs()
+	for b.Loop() {
+		if _, err := Call[*benchSendReq, benchMsgResp](ctx, bot, "sendMessage", req); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkEncodeJSONBody(b *testing.B) {
+	codec := DefaultCodec{}
+	req := &benchSendReq{ChatID: 42, Text: "hello, world"}
+	b.ReportAllocs()
+	for b.Loop() {
+		r, err := encodeJSONBody(codec, req)
+		if err != nil {
+			b.Fatal(err)
+		}
+		_ = r
+	}
+}
+
+func BenchmarkDecodeResult_Bool(b *testing.B) {
+	codec := DefaultCodec{}
+	raw := []byte(`{"ok":true,"result":true}`)
+	b.ReportAllocs()
+	for b.Loop() {
+		if _, err := decodeResult[bool](codec, raw); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkDecodeResult_Struct(b *testing.B) {
+	codec := DefaultCodec{}
+	raw := []byte(`{"ok":true,"result":{"message_id":1,"date":0,"text":"ok"}}`)
+	b.ReportAllocs()
+	for b.Loop() {
+		if _, err := decodeResult[benchMsgResp](codec, raw); err != nil {
+			b.Fatal(err)
+		}
+	}
+}

dispatch/router_bench_test.go

@@ -0,0 +1,89 @@
+package dispatch
+
+import (
+	"context"
+	"testing"
+
+	"github.com/lukaszraczylo/go-telegram/api"
+	"github.com/lukaszraczylo/go-telegram/client"
+)
+
+func BenchmarkRouter_DispatchCommand(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnCommand("/start", func(c *Context, m *api.Message) error { return nil })
+	u := cmdMessage("/start hello")
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_DispatchTextRegex(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnText("^hello.*", func(c *Context, m *api.Message) error { return nil })
+	u := api.Update{
+		UpdateID: 1,
+		Message: &api.Message{
+			MessageID: 1, Date: 0,
+			Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+			Text: "hello world",
+		},
+	}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_DispatchFilter(b *testing.B) {
+	r := New(client.New("t"))
+	r.OnMessageFilter(
+		func(m *api.Message) bool { return m != nil && m.Text == "ping" },
+		func(c *Context, m *api.Message) error { return nil },
+	)
+	u := api.Update{
+		UpdateID: 1,
+		Message: &api.Message{
+			MessageID: 1, Date: 0,
+			Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+			Text: "ping",
+		},
+	}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		c := NewContext(ctx, r.bot, &u)
+		_ = r.dispatch(c, &u)
+	}
+}
+
+func BenchmarkRouter_NewContext(b *testing.B) {
+	bot := client.New("t")
+	u := &api.Update{UpdateID: 1}
+	ctx := context.Background()
+	b.ReportAllocs()
+	for b.Loop() {
+		_ = NewContext(ctx, bot, u)
+	}
+}
+
+func BenchmarkExtractCommand(b *testing.B) {
+	text := "/start@BotName hello world"
+	cmdLen := len("/start@BotName")
+	m := &api.Message{
+		MessageID: 1, Date: 0,
+		Chat: api.Chat{ID: 1, Type: api.ChatTypePrivate},
+		Text: text,
+		Entities: []api.MessageEntity{
+			{Type: api.MessageEntityTypeBotCommand, Offset: 0, Length: int64(cmdLen)},
+		},
+	}
+	b.ReportAllocs()
+	for b.Loop() {
+		_, _, _ = extractCommand(m)
+	}
+}

transport/webhook_bench_test.go

@@ -0,0 +1,39 @@
+package transport
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/lukaszraczylo/go-telegram/client"
+)
+
+const benchUpdateBody = `{"update_id":12345,"message":{"message_id":1,"date":1700000000,"chat":{"id":42,"type":"private"},"from":{"id":42,"is_bot":false,"first_name":"User"},"text":"hello world"}}`
+
+func BenchmarkWebhook_ServeHTTP(b *testing.B) {
+	w := NewWebhookServer(client.New("t"), WithBufferSize(1024))
+	body := []byte(benchUpdateBody)
+
+	done := make(chan struct{})
+	go func() {
+		for {
+			select {
+			case <-w.Updates():
+			case <-done:
+				return
+			}
+		}
+	}()
+	defer close(done)
+
+	b.ReportAllocs()
+	for b.Loop() {
+		req := httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(body))
+		rec := httptest.NewRecorder()
+		w.ServeHTTP(rec, req)
+		if rec.Code != http.StatusOK {
+			b.Fatalf("status %d", rec.Code)
+		}
+	}
+}