Modernize for Go 1.27.2 and pin GitHub Actions

.github/workflows/go.yml

@@ -16,35 +16,30 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: golangci/golangci-lint-action@v2
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
+        with:
+          go-version-file: go.mod
+      - uses: golangci/golangci-lint-action@ba0d7d2ec06a0ea1cb5fa41b2e4a3ab91d21278a # v9.3.0
+        with:
+          version: v2.14.0
+      - name: Check formatting
+        run: golangci-lint fmt --diff
   test:
-    name: Test (latest major)
+    name: Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-go@v4
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
-          go-version: "~1.23.4"
+          go-version-file: go.mod
       - name: Test
         run: go test -v -timeout=1s -coverprofile=coverage.txt -covermode=atomic ./...
       - name: Test (race)
         run: go test -v -timeout=1s -race ./...
       - name: Coverage
-        uses: codecov/codecov-action@v3
-        if: github.ref == 'refs/head/master'
+        uses: codecov/codecov-action@303a32d7a59b442fa8d48b6a1cc6825c09c847a5 # v7.1.1
+        if: github.ref == 'refs/heads/master'
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./coverage.txt
-  test-old:
-    name: Test (previous major)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-go@v4
-        with:
-          go-version: "~1.22.10"
-      - name: Test
-        run: go test -v -timeout=1s ./...
-      - name: Test (race)
-        run: go test -v -timeout=1s -race ./...

.golangci.yml

@@ -1,58 +1,71 @@
+version: "2"
 linters:
   enable:
-    - errcheck
-    - gosimple
-    - govet
-    - ineffassign
-    - staticcheck
-    - typecheck
     - dogsled
     - dupl
     - errorlint
     - exhaustive
-    - nestif
     - goconst
     - gocritic
     - gocyclo
     - godot
     - godox
-    - gofmt
-    - gofumpt
     - goheader
-    - goimports
     - gomoddirectives
-    - gomodguard
+    - gomodguard_v2
     - gosec
     - importas
     - makezero
     - misspell
+    - nestif
+    - nolintlint
     - prealloc
-    - promlinter
     - predeclared
-    - nolintlint
+    - promlinter
     - revive
-    - stylecheck
+    - staticcheck
     - tagliatelle
     - thelper
     - unparam
-    - unused
     - whitespace
-linters-settings:
-  gosec:
-    excludes:
-      - G404
-  gocritic:
-    disabled-checks:
-      - ifElseChain
-      - unnamedResult
-      - hugeParam
-    enabled-tags:
-      - performance
-      - diagnostic
-      - experimental
-      - opinionated
-  nestif:
-    min-complexity: 8
-  govet:
-    enable:
-      - fieldalignment
+  settings:
+    gocritic:
+      disabled-checks:
+        - ifElseChain
+        - unnamedResult
+        - hugeParam
+      enabled-tags:
+        - performance
+        - diagnostic
+        - experimental
+        - opinionated
+    gosec:
+      excludes:
+        - G404
+    govet:
+      enable:
+        - fieldalignment
+    nestif:
+      min-complexity: 8
+  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$

README.md

@@ -42,7 +42,7 @@ The library provides both server-side and client-side implementations of the pro
 
 If you are not familiar with the protocol or not sure how it works, read [MDN's guide for using server-sent events](https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events). [The spec](https://html.spec.whatwg.org/multipage/server-sent-events.html) is also useful read!
 
-`go-sse` promises to support the [Go versions supported by the Go team](https://go.dev/doc/devel/release#policy) – that is, the 2 most recent major releases.
+`go-sse` requires Go 1.27.2 or later.
 
 ## Cut to the chase – how do I read my LLM's response?
 
@@ -70,13 +70,7 @@ for ev, err := range sse.Read(res.Body, nil) {
 
 See the [LLM example](cmd/llm/main.go) for a fully working Go program.
 
-Go 1.23 iterators (officially ["range-over-func"](https://go.dev/blog/range-functions)) are used for this feature. If you are still on Go 1.22 use the `GOEXPERIMENT=rangefunc` environment variable (e.g. `GOEXPERIMENT=rangefunc go run main.go`) or use the iterator without the syntactic sugar:
-```go
-events(func(ev Event) bool {
-    // do something with event
-    return true // or false to stop iteration
-})
-```
+This feature uses Go's [range-over-function iterators](https://go.dev/blog/range-functions).
 
 `sse.Read` is also useful if you're implementing an LLM SDK: call it in your code and spare yourself time and maintenance burden by not reimplementing event stream parsing.
 

client_test.go

@@ -565,8 +565,7 @@ func TestConnection_serverError(t *testing.T) {
 		ResponseValidator: sse.NoopValidator,
 		Backoff:           sse.Backoff{MaxRetries: -1},
 	}
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 	conn := c.NewConnection(reqCtx(t, ctx, "", ts.URL, nil))
 
 	all, unsubAll := events(t, conn)

cmd/complex/main.go

@@ -37,11 +37,9 @@ func newSSE() *sse.Server {
 			topics = r.URL.Query()["topic"]
 			for _, topic := range topics {
 				if topic != topicRandomNumbers && topic != topicMetrics {
-					fmt.Fprintf(w, "invalid topic %q; supported are %q, %q", topic, topicRandomNumbers, topicMetrics)
-
 					// NOTE: if you are returning false to reject the subscription, we strongly recommend writing
 					// your own response code. Clients will receive a 200 code otherwise, which may be confusing.
-					w.WriteHeader(http.StatusBadRequest)
+					http.Error(w, fmt.Sprintf("invalid topic %q; supported are %q, %q", topic, topicRandomNumbers, topicMetrics), http.StatusBadRequest)
 					return nil, false
 				}
 			}
@@ -161,7 +159,7 @@ func runServer(ctx context.Context, s *http.Server) error {
 	go func() {
 		<-ctx.Done()
 
-		sctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
+		sctx, cancel := context.WithTimeout(context.WithoutCancel(ctx), time.Second*10)
 		defer cancel()
 
 		shutdownError <- s.Shutdown(sctx)
@@ -178,7 +176,7 @@ func generateRandomNumbers() *sse.Message {
 	e := &sse.Message{}
 	count := 1 + rand.Intn(5)
 
-	for i := 0; i < count; i++ {
+	for range count {
 		e.AppendData(strconv.FormatUint(rand.Uint64(), 10))
 	}
 

cmd/complex/metrics.go

@@ -27,7 +27,7 @@ func Inc(metric string) int64 {
 
 // Range loops through all metrics and calls the given function for each metric.
 func Range(fn func(key string, value int64) bool) {
-	metrics.Range(func(key, value interface{}) bool {
+	metrics.Range(func(key, value any) bool {
 		return fn(key.(string), value.(int64))
 	})
 }

cmd/complex_client/main.go

@@ -35,7 +35,7 @@ func main() {
 			cancel()
 		default: // no event name
 			var sum, num big.Int
-			for _, n := range strings.Split(event.Data, "\n") {
+			for n := range strings.SplitSeq(event.Data, "\n") {
 				_, _ = num.SetString(n, 10)
 				sum.Add(&sum, &num)
 			}

cmd/llm/main.go

@@ -1,5 +1,3 @@
-//go:build go1.23
-
 package main
 
 import (

event.go

@@ -126,7 +126,7 @@ func read(pf func() *parser.Parser, lastEventID string, onRetry func(int64), ign
 			}
 		}
 
-		if err != nil && !(ignoreEOF && isEOF) {
+		if err != nil && (!ignoreEOF || !isEOF) {
 			yield(Event{}, err)
 		}
 	}

go.mod

@@ -1,3 +1,3 @@
 module github.com/tmaxmax/go-sse
 
-go 1.22
+go 1.27.2

internal/parser/field_parser_test.go

@@ -91,8 +91,6 @@ func TestFieldParser(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		test := test
-
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 

internal/parser/parser_test.go

@@ -105,8 +105,6 @@ data: still, here's some data: you deserve it
 	}
 
 	for _, test := range tests {
-		test := test
-
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 

internal/parser/split_func_test.go

@@ -40,8 +40,6 @@ func TestSplitFunc(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		tc := tc
-
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
 

joe.go

@@ -171,9 +171,11 @@ func (j *Joe) Publish(msg *Message, topics []string) error {
 	// message published causes an error after the shutdown.
 	errs := make(chan error, 1)
 
-	pub := publishedMessage{replayerErr: errs}
-	pub.message = msg
-	pub.topics = topics
+	pub := publishedMessage{
+		replayerErr: errs,
+		message:     msg,
+		topics:      topics,
+	}
 
 	// Waiting on done ensures Publish doesn't block the caller goroutine
 	// when Joe is stopped and implements the required Provider behavior.

message_fields.go

@@ -151,7 +151,7 @@ func (i *messageField) MarshalJSON() ([]byte, error) {
 //   - nil interfaces (result: unset value)
 //   - byte slice
 //   - string
-func (i *messageField) Scan(src interface{}) error {
+func (i *messageField) Scan(src any) error {
 	*i = messageField{}
 
 	if src == nil {

message_fields_test.go

@@ -48,8 +48,6 @@ func TestMessageField_UnmarshalJSON(t *testing.T) {
 	}
 
 	for _, test := range tt {
-		test := test
-
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 

replay.go

@@ -2,6 +2,7 @@ package sse
 
 import (
 	"errors"
+	"slices"
 	"strconv"
 	"time"
 )
@@ -157,7 +158,7 @@ func (v *ValidReplayer) Put(message *Message, topics []string) (*Message, error)
 		v.messages.resize(newCap)
 	}
 
-	v.messages.enqueue(messageWithTopicsAndExpiry{messageWithTopics: messageWithTopics{message: message, topics: topics}, exp: now.Add(v.ttl)})
+	v.messages.enqueue(messageWithTopicsAndExpiry{message: message, topics: topics, exp: now.Add(v.ttl)})
 
 	return message, nil
 }
@@ -218,10 +219,8 @@ func (v *ValidReplayer) Replay(subscription Subscription) error {
 // topicsIntersect returns true if the given topic slices have at least one topic in common.
 func topicsIntersect(a, b []string) bool {
 	for _, at := range a {
-		for _, bt := range b {
-			if at == bt {
-				return true
-			}
+		if slices.Contains(b, at) {
+			return true
 		}
 	}
 

replay_test.go

@@ -186,7 +186,7 @@ func TestFiniteReplayProvider_allocations(t *testing.T) {
 	queue := make([]*sse.Message, runs+1)
 	lastID := runs
 
-	for i := 0; i < len(queue); i++ {
+	for i := range queue {
 		queue[i] = msg(t,
 			fmt.Sprintf("message %d", i),
 			strconv.Itoa(i),

server_test.go

@@ -263,7 +263,7 @@ func benchmarkServer(b *testing.B, conns int) {
 
 	m := getMessage(b)
 
-	for i := 0; i < conns; i++ {
+	for range conns {
 		w, r := getRequest(b)
 		go s.ServeHTTP(w, r)
 	}