chore: improve linting and error handling across the codebase

- Update golangci-lint-action to version 7 in GitHub workflow
- Specify version 2.0 for golangci-lint-action in GitHub workflow
- Set golangci-lint configuration version to "2"
- Enable specific linters and disable default linters in golangci configuration
- Add exclusions and formatters configurations in golangci configuration
- Replace deprecated `ioutil.ReadAll` with `io.ReadAll` in sse-decoder.go
- Use grouped variable declaration for `contentType` and `noCache` in sse-encoder.go
- Add error handling for `WriteString` operations in sse-encoder.go
- Add `nolint:exhaustive` comment for `kindOfData` switch statement in sse-encoder.go
- Adjust test assertions for better readability in sse_test.go
- Add error handling for `Encode` function calls in tests and benchmarks

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.github/workflows/go.yml

@@ -21,8 +21,9 @@ jobs:
           go-version: "^1"
 
       - name: Setup golangci-lint
-        uses: golangci/golangci-lint-action@v6
+        uses: golangci/golangci-lint-action@v7
         with:
+          version: v2.0
           args: --verbose
 
       - name: Bearer

.golangci.yml

@@ -1,3 +1,50 @@
+version: "2"
 linters:
-  disable:
+  default: none
+  enable:
+    - bodyclose
+    - dogsled
+    - dupl
     - errcheck
+    - exhaustive
+    - gochecknoinits
+    - goconst
+    - gocritic
+    - gocyclo
+    - goprintffuncname
+    - gosec
+    - govet
+    - ineffassign
+    - lll
+    - misspell
+    - nakedret
+    - noctx
+    - nolintlint
+    - rowserrcheck
+    - staticcheck
+    - unconvert
+    - unparam
+    - unused
+    - whitespace
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
+  enable:
+    - gofmt
+    - gofumpt
+    - goimports
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$

sse-decoder.go

@@ -7,7 +7,6 @@ package sse
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 )
 
 type decoder struct {
@@ -22,7 +21,8 @@ func Decode(r io.Reader) ([]Event, error) {
 func (d *decoder) dispatchEvent(event Event, data string) {
 	dataLength := len(data)
 	if dataLength > 0 {
-		//If the data buffer's last character is a U+000A LINE FEED (LF) character, then remove the last character from the data buffer.
+		// If the data buffer's last character is a U+000A LINE FEED (LF) character,
+		// then remove the last character from the data buffer.
 		data = data[:dataLength-1]
 		dataLength--
 	}
@@ -37,7 +37,7 @@ func (d *decoder) dispatchEvent(event Event, data string) {
 }
 
 func (d *decoder) decode(r io.Reader) ([]Event, error) {
-	buf, err := ioutil.ReadAll(r)
+	buf, err := io.ReadAll(r)
 	if err != nil {
 		return nil, err
 	}
@@ -96,7 +96,8 @@ func (d *decoder) decode(r io.Reader) ([]Event, error) {
 			currentEvent.Id = string(value)
 		case "retry":
 			// If the field value consists of only characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9),
-			// then interpret the field value as an integer in base ten, and set the event stream's reconnection time to that integer.
+			// then interpret the field value as an integer in base ten, and set the event stream's
+			// reconnection time to that integer.
 			// Otherwise, ignore the field.
 			currentEvent.Id = string(value)
 		case "data":
@@ -105,7 +106,7 @@ func (d *decoder) decode(r io.Reader) ([]Event, error) {
 			// then append a single U+000A LINE FEED (LF) character to the data buffer.
 			dataBuffer.WriteString("\n")
 		default:
-			//Otherwise. The field is ignored.
+			// Otherwise. The field is ignored.
 			continue
 		}
 	}

sse-encoder.go

@@ -20,8 +20,10 @@ import (
 
 const ContentType = "text/event-stream;charset=utf-8"
 
-var contentType = []string{ContentType}
-var noCache = []string{"no-cache"}
+var (
+	contentType = []string{ContentType}
+	noCache     = []string{"no-cache"}
+)
 
 var fieldReplacer = strings.NewReplacer(
 	"\n", "\\n",
@@ -48,48 +50,48 @@ func Encode(writer io.Writer, event Event) error {
 
 func writeId(w stringWriter, id string) {
 	if len(id) > 0 {
-		w.WriteString("id:")
-		fieldReplacer.WriteString(w, id)
-		w.WriteString("\n")
+		_, _ = w.WriteString("id:")
+		_, _ = fieldReplacer.WriteString(w, id)
+		_, _ = w.WriteString("\n")
 	}
 }
 
 func writeEvent(w stringWriter, event string) {
 	if len(event) > 0 {
-		w.WriteString("event:")
-		fieldReplacer.WriteString(w, event)
-		w.WriteString("\n")
+		_, _ = w.WriteString("event:")
+		_, _ = fieldReplacer.WriteString(w, event)
+		_, _ = w.WriteString("\n")
 	}
 }
 
 func writeRetry(w stringWriter, retry uint) {
 	if retry > 0 {
-		w.WriteString("retry:")
-		w.WriteString(strconv.FormatUint(uint64(retry), 10))
-		w.WriteString("\n")
+		_, _ = w.WriteString("retry:")
+		_, _ = w.WriteString(strconv.FormatUint(uint64(retry), 10))
+		_, _ = w.WriteString("\n")
 	}
 }
 
 func writeData(w stringWriter, data interface{}) error {
-	w.WriteString("data:")
+	_, _ = w.WriteString("data:")
 
 	bData, ok := data.([]byte)
 	if ok {
-		dataReplacer.WriteString(w, string(bData))
-		w.WriteString("\n\n")
+		_, _ = dataReplacer.WriteString(w, string(bData))
+		_, _ = w.WriteString("\n\n")
 		return nil
 	}
 
-	switch kindOfData(data) {
+	switch kindOfData(data) { //nolint:exhaustive
 	case reflect.Struct, reflect.Slice, reflect.Map:
 		err := json.NewEncoder(w).Encode(data)
 		if err != nil {
 			return err
 		}
-		w.WriteString("\n")
+		_, _ = w.WriteString("\n")
 	default:
-		dataReplacer.WriteString(w, fmt.Sprint(data))
-		w.WriteString("\n\n")
+		_, _ = dataReplacer.WriteString(w, fmt.Sprint(data))
+		_, _ = w.WriteString("\n\n")
 	}
 	return nil
 }

sse_test.go

@@ -170,22 +170,25 @@ func TestEncodeFloat(t *testing.T) {
 func TestEncodeStream(t *testing.T) {
 	w := new(bytes.Buffer)
 
-	Encode(w, Event{
+	_ = Encode(w, Event{
 		Event: "float",
 		Data:  1.5,
 	})
 
-	Encode(w, Event{
+	_ = Encode(w, Event{
 		Id:   "123",
 		Data: map[string]interface{}{"foo": "bar", "bar": "foo"},
 	})
 
-	Encode(w, Event{
+	_ = Encode(w, Event{
 		Id:    "124",
 		Event: "chat",
 		Data:  "hi! dude",
 	})
-	assert.Equal(t, w.String(), "event:float\ndata:1.5\n\nid:123\ndata:{\"bar\":\"foo\",\"foo\":\"bar\"}\n\nid:124\nevent:chat\ndata:hi! dude\n\n")
+	assert.Equal(t, w.String(),
+		"event:float\ndata:1.5\n\n"+
+			"id:123\ndata:{\"bar\":\"foo\",\"foo\":\"bar\"}\n\n"+
+			"id:124\nevent:chat\ndata:hi! dude\n\n")
 }
 
 func TestRenderSSE(t *testing.T) {
@@ -207,7 +210,7 @@ func BenchmarkResponseWriter(b *testing.B) {
 	b.ResetTimer()
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
-		(Event{
+		_ = (Event{
 			Event: "new_message",
 			Data:  "hi! how are you? I am fine. this is a long stupid message!!!",
 		}).Render(w)
@@ -219,7 +222,7 @@ func BenchmarkFullSSE(b *testing.B) {
 	b.ResetTimer()
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
-		Encode(buf, Event{
+		_ = Encode(buf, Event{
 			Event: "new_message",
 			Id:    "13435",
 			Retry: 10,
@@ -234,7 +237,7 @@ func BenchmarkNoRetrySSE(b *testing.B) {
 	b.ResetTimer()
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
-		Encode(buf, Event{
+		_ = Encode(buf, Event{
 			Event: "new_message",
 			Id:    "13435",
 			Data:  "hi! how are you? I am fine. this is a long stupid message!!!",
@@ -248,7 +251,7 @@ func BenchmarkSimpleSSE(b *testing.B) {
 	b.ResetTimer()
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
-		Encode(buf, Event{
+		_ = Encode(buf, Event{
 			Event: "new_message",
 			Data:  "hi! how are you? I am fine. this is a long stupid message!!!",
 		})