.github: ensure golangci-lint runs on PR's as well

.github/workflows/golangci-lint.yml

@@ -9,6 +9,10 @@ name: golangci-lint
       - '**.go'
       - .golangci.yml
       - .github/workflows/golangci-lint.yml
+  pull_request:
+    branches:
+      - main
+
 
 jobs:
   lint:

.golangci.yml

@@ -1,8 +1,5 @@
 run:
   deadline: 5m
-  skip-files:
-    # Skip autogenerated files.
-    - ^.*\.(pb|y)\.go$
 
 output:
   sort-results: true
@@ -20,6 +17,9 @@ linters:
     - misspell
 
 issues:
+  exclude-files:
+    # Skip autogenerated files.
+    - ^.*\.(pb|y)\.go$
   exclude-rules:
     - path: _test.go
       linters:

buffer.go

@@ -156,7 +156,7 @@ func (b *buffer) len() int {
 }
 
 func (b *buffer) flush(w io.Writer, n int) {
-	w.Write(b.data[:n])
+	_, _ = w.Write(b.data[:n])
 	n = copy(b.data, b.data[n:])
 	b.data = b.data[:n]
 }

cmd/dogstatsd/main.go

@@ -59,7 +59,7 @@ func client(cmd string, args ...string) {
 	args, extra = split(args, "--")
 	fset.StringVar(&addr, "addr", "localhost:8125", "The network address where a dogstatsd server is listening for incoming UDP datagrams")
 	fset.Var(&tags, "tags", "A comma-separated list of tags to set on the metric")
-	fset.Parse(args)
+	_ = fset.Parse(args)
 	args = fset.Args()
 
 	if len(args) == 0 {
@@ -74,17 +74,13 @@ func client(cmd string, args ...string) {
 			value = 1.0
 		} else if value, err = strconv.ParseFloat(args[0], 64); err != nil {
 			errorf("bad metric value: %s", args[0])
-		} else {
-			args = args[1:]
 		}
 
 	case "set":
 		if len(args) == 0 {
 			errorf("missing metric value")
 		} else if value, err = strconv.ParseFloat(args[0], 64); err != nil {
 			errorf("bad metric value: %s", args[0])
-		} else {
-			args = args[1:]
 		}
 	}
 
@@ -110,19 +106,19 @@ func server(args ...string) {
 	var bind string
 
 	fset.StringVar(&bind, "bind", ":8125", "The network address to listen on for incoming UDP datagrams")
-	fset.Parse(args)
+	_ = fset.Parse(args)
 	log.Printf("listening for incoming UDP datagram on %s", bind)
 
-	datadog.ListenAndServe(bind, handlers{})
+	_ = datadog.ListenAndServe(bind, handlers{})
 }
 
 type handlers struct{}
 
-func (h handlers) HandleMetric(m datadog.Metric, a net.Addr) {
+func (h handlers) HandleMetric(m datadog.Metric, _ net.Addr) {
 	log.Print(m)
 }
 
-func (h handlers) HandleEvent(e datadog.Event, a net.Addr) {
+func (h handlers) HandleEvent(e datadog.Event, _ net.Addr) {
 	log.Print(e)
 }
 

context_test.go

@@ -17,7 +17,8 @@ func TestContextTags(t *testing.T) {
 	assert.Equal(t, 0, len(ContextTags(x)), "Original context should have no tags (because no context with key)")
 
 	// create a child context which creates a child context
-	z := context.WithValue(y, interface{}("not"), "important")
+	type unimportant struct{}
+	z := context.WithValue(y, unimportant{}, "important")
 	assert.Equal(t, 1, len(ContextTags(z)), "We should still be able to see original tags")
 
 	// Add tags to the child context's reference to the original tag slice

datadog/append_test.go

@@ -4,7 +4,7 @@ import "testing"
 
 func TestAppendMetric(t *testing.T) {
 	for _, test := range testMetrics {
-		t.Run(test.m.Name, func(b *testing.T) {
+		t.Run(test.m.Name, func(t *testing.T) {
 			if s := string(appendMetric(nil, test.m)); s != test.s {
 				t.Errorf("\n<<< %#v\n>>> %#v", test.s, s)
 			}

datadog/client.go

@@ -4,10 +4,11 @@ import (
 	"log"
 	"net"
 	"os"
-	"syscall"
 	"time"
 
 	"github.com/segmentio/stats/v4"
+
+	"golang.org/x/sys/unix"
 )
 
 const (
@@ -158,7 +159,7 @@ func dial(address string, sizehint int) (conn net.Conn, bufsize int, err error)
 	// sent in one batch we attempt to attempt to adjust the kernel buffer size
 	// to accept larger datagrams, or fallback to the default socket buffer size
 	// if it failed.
-	if bufsize, err = syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUF); err != nil {
+	if bufsize, err = unix.GetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF); err != nil {
 		conn.Close()
 		return
 	}
@@ -169,7 +170,7 @@ func dial(address string, sizehint int) (conn net.Conn, bufsize int, err error)
 	bufsize /= 2
 
 	for sizehint > bufsize && sizehint > 0 {
-		if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUF, sizehint); err == nil {
+		if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, sizehint); err == nil {
 			bufsize = sizehint
 			break
 		}
@@ -194,6 +195,6 @@ func dial(address string, sizehint int) (conn net.Conn, bufsize int, err error)
 	}
 
 	// Creating the file put the socket in blocking mode, reverting.
-	syscall.SetNonblock(fd, true)
+	_ = unix.SetNonblock(fd, true)
 	return
 }

datadog/client_test.go

@@ -1,19 +1,19 @@
 package datadog
 
 import (
+	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net"
 	"strings"
 	"sync/atomic"
 	"testing"
 	"time"
 
-	"github.com/stretchr/testify/assert"
-
 	"github.com/segmentio/stats/v4"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestClient(t *testing.T) {
@@ -72,7 +72,7 @@ func TestClientWithUseDistributions(t *testing.T) {
 		UseDistributions: true,
 	})
 
-	testMeassure := stats.Measure{
+	testMeasure := stats.Measure{
 		Name: "request",
 		Fields: []stats.Field{
 			{Name: "count", Value: stats.ValueOf(5)},
@@ -83,14 +83,14 @@ func TestClientWithUseDistributions(t *testing.T) {
 			stats.T("hello", "world"),
 		},
 	}
-	client.HandleMeasures(time.Time{}, testMeassure)
+	client.HandleMeasures(time.Time{}, testMeasure)
 	client.Flush()
 
 	expectedPacket1 := "request.count:5|c|#answer:42,hello:world\nrequest.dist_rtt:0.1|d|#answer:42,hello:world\n"
 	assert.EqualValues(t, expectedPacket1, string(<-packets))
 
 	client.useDistributions = false
-	client.HandleMeasures(time.Time{}, testMeassure)
+	client.HandleMeasures(time.Time{}, testMeasure)
 	client.Flush()
 
 	expectedPacket2 := "request.count:5|c|#answer:42,hello:world\nrequest.dist_rtt:0.1|h|#answer:42,hello:world\n"
@@ -117,7 +117,7 @@ main.http.rtt.seconds:0.001215296|h|#http_req_content_charset:,http_req_content_
 	count := int32(0)
 	expect := int32(strings.Count(data, "\n"))
 
-	addr, closer := startTestServer(t, HandlerFunc(func(m Metric, _ net.Addr) {
+	addr, closer := startTestServer(t, HandlerFunc(func(_ Metric, _ net.Addr) {
 		atomic.AddInt32(&count, 1)
 	}))
 	defer closer.Close()
@@ -136,7 +136,7 @@ main.http.rtt.seconds:0.001215296|h|#http_req_content_charset:,http_req_content_
 }
 
 func BenchmarkClient(b *testing.B) {
-	log.SetOutput(ioutil.Discard)
+	log.SetOutput(io.Discard)
 
 	for _, N := range []int{1, 10, 100} {
 		b.Run(fmt.Sprintf("write a batch of %d measures to a client", N), func(b *testing.B) {
@@ -169,6 +169,14 @@ func BenchmarkClient(b *testing.B) {
 	}
 }
 
+func isClosedNetworkConnectionErr(err error) bool {
+	var netErr *net.OpError
+	if errors.As(err, &netErr) {
+		return strings.Contains(netErr.Err.Error(), "use of closed network connection")
+	}
+	return false
+}
+
 // startUDPListener starts a goroutine listening for UDP packets on 127.0.0.1 and an available port.
 // The address listened to is returned as `addr`. The payloads of packets received are copied to `packets`.
 func startUDPListener(t *testing.T, packets chan []byte) (addr string, closer io.Closer) {
@@ -186,7 +194,9 @@ func startUDPListener(t *testing.T, packets chan []byte) (addr string, closer io
 			}
 
 			if err != nil {
-				t.Log(err)
+				if !isClosedNetworkConnectionErr(err) {
+					fmt.Println("err reading from UDP connection in goroutine:", err)
+				}
 				return
 			}
 		}

datadog/event.go

@@ -51,6 +51,6 @@ func (e Event) String() string {
 func (e Event) Format(f fmt.State, _ rune) {
 	buf := bufferPool.Get().(*buffer)
 	buf.b = appendEvent(buf.b[:0], e)
-	f.Write(buf.b)
+	_, _ = f.Write(buf.b)
 	bufferPool.Put(buf)
 }

datadog/metric.go

@@ -39,7 +39,7 @@ func (m Metric) String() string {
 func (m Metric) Format(f fmt.State, _ rune) {
 	buf := bufferPool.Get().(*buffer)
 	buf.b = appendMetric(buf.b[:0], m)
-	f.Write(buf.b)
+	_, _ = f.Write(buf.b)
 	bufferPool.Put(buf)
 }
 

datadog/server.go

@@ -33,9 +33,7 @@ func (f HandlerFunc) HandleMetric(m Metric, a net.Addr) {
 }
 
 // HandleEvent is a no-op for backwards compatibility.
-func (f HandlerFunc) HandleEvent(Event, net.Addr) {
-	return
-}
+func (f HandlerFunc) HandleEvent(Event, net.Addr) {}
 
 // ListenAndServe starts a new dogstatsd server, listening for UDP datagrams on
 // addr and forwarding the metrics to handler.

engine_test.go

@@ -64,6 +64,10 @@ func TestEngine(t *testing.T) {
 			scenario: "calling Engine.Clock produces expected metrics",
 			function: testEngineClock,
 		},
+		{
+			scenario: "calling Engine.WithTags produces expected tags",
+			function: testEngineWithTags,
+		},
 	}
 
 	for _, test := range tests {
@@ -307,6 +311,7 @@ func checkMeasuresEqual(t *testing.T, eng *stats.Engine, expected ...stats.Measu
 }
 
 func measures(t *testing.T, eng *stats.Engine) []stats.Measure {
+	t.Helper()
 	return eng.Handler.(*statstest.Handler).Measures()
 }
 

field_test.go

@@ -17,10 +17,10 @@ func BenchmarkAssign40BytesStruct(b *testing.B) {
 		c int
 	}
 
-	s := S{}
+	var s S
 
 	for i := 0; i != b.N; i++ {
-		s = S{a: "hello"}
+		s = S{a: "hello", b: "", c: 0}
 		_ = s
 	}
 }
@@ -31,10 +31,10 @@ func BenchmarkAssign32BytesStruct(b *testing.B) {
 		b string
 	}
 
-	s := S{}
+	var s S
 
 	for i := 0; i != b.N; i++ {
-		s = S{a: "hello"}
+		s = S{a: "hello", b: ""}
 		_ = s
 	}
 }

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/exp v0.0.0-20231206192017-f3f8817b8deb
 	golang.org/x/sync v0.3.0
+	golang.org/x/sys v0.12.0
 )
 
 require github.com/davecgh/go-spew v1.1.1 // indirect
@@ -20,7 +21,6 @@ require (
 	github.com/mdlayher/netlink v0.0.0-20190313131330-258ea9dff42c // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/net v0.7.0 // indirect
-	golang.org/x/sys v0.12.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

grafana/annotations.go

@@ -117,7 +117,7 @@ type annotationsResponse struct {
 }
 
 func (res *annotationsResponse) WriteAnnotation(a Annotation) {
-	res.enc.Encode(annotationInfo{
+	_ = res.enc.Encode(annotationInfo{
 		Annotation: annotation{
 			Name:       res.name,
 			Datasource: res.datasource,

grafana/annotations_test.go

@@ -4,7 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -28,7 +28,7 @@ func TestAnnotationsHandler(t *testing.T) {
 
 	client := http.Client{}
 	server := httptest.NewServer(NewAnnotationsHandler(
-		AnnotationsHandlerFunc(func(ctx context.Context, res AnnotationsResponse, req *AnnotationsRequest) error {
+		AnnotationsHandlerFunc(func(_ context.Context, res AnnotationsResponse, req *AnnotationsRequest) error {
 			if !req.From.Equal(ar.Range.From) {
 				t.Error("bad 'from' time:", req.From, ar.Range.From)
 			}
@@ -79,7 +79,7 @@ func TestAnnotationsHandler(t *testing.T) {
 	}
 	defer r.Body.Close()
 
-	found, _ := ioutil.ReadAll(r.Body)
+	found, _ := io.ReadAll(r.Body)
 	expect := annotationsResult
 
 	if s := string(found); s != expect {

grafana/handler.go

@@ -47,7 +47,7 @@ func Handle(mux *http.ServeMux, prefix string, handler Handler) {
 	if _, pattern := mux.Handler(&http.Request{
 		URL: &url.URL{Path: root},
 	}); len(pattern) == 0 {
-		mux.HandleFunc(root, func(res http.ResponseWriter, req *http.Request) {
+		mux.HandleFunc(root, func(res http.ResponseWriter, _ *http.Request) {
 			setResponseHeaders(res)
 		})
 	}

grafana/query.go

@@ -191,13 +191,13 @@ func (res *queryResponse) close() error {
 
 func (res *queryResponse) flush() {
 	if res.timeserie != nil {
-		res.enc.Encode(res.timeserie)
+		_ = res.enc.Encode(res.timeserie)
 		res.timeserie.closed = true
 		res.timeserie = nil
 	}
 
 	if res.table != nil {
-		res.enc.Encode(res.table)
+		_ = res.enc.Encode(res.table)
 		res.table.closed = true
 		res.table = nil
 	}

grafana/query_test.go

@@ -32,7 +32,7 @@ func TestQueryHandler(t *testing.T) {
 
 	client := http.Client{}
 	server := httptest.NewServer(NewQueryHandler(
-		QueryHandlerFunc(func(ctx context.Context, res QueryResponse, req *QueryRequest) error {
+		QueryHandlerFunc(func(_ context.Context, res QueryResponse, req *QueryRequest) error {
 			if !req.From.Equal(t0) {
 				t.Error("bad 'from' time:", req.From, "!=", t0)
 			}