chore: add golangci-lint (#156)

Author: korniltsev

.github/workflows/check_golang_profiler_changes.yml

@@ -10,6 +10,21 @@ permissions:
   contents: read
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - name: Install Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.22'
+
+      - run: make lint
+
   go:
     runs-on: ubuntu-latest
     strategy:
@@ -59,7 +74,7 @@ jobs:
           make gotip/fix
 
       - name: Build example application
-        run: go build example/main.go
+        run: make examples
 
       - name: Run tests
         run: |

.github/workflows/go.yml

@@ -31,7 +31,7 @@ jobs:
           echo "$HOME/sdk/gotip/bin" >> "$GITHUB_PATH"
           make gotip/fix
       - name: Build example application
-        run: go build example/main.go
+        run: make examples
       - name: Run tests
         run: |
           which go

.github/workflows/gotip_cron_test.yml

@@ -1,4 +1,6 @@
 .idea/
 .vscode/
+.tools/
 
 main
+timing

.gitignore

@@ -0,0 +1,49 @@
+version: "2"
+
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  settings:
+    gofmt:
+      simplify: true
+    goimports:
+      local-prefixes:
+        - github.com/grafana/pyroscope-go
+
+
+run:
+  timeout: 10m
+  tests: true
+
+linters:
+  default: all
+  disable:
+    - wsl
+    - wsl_v5
+    - cyclop
+    - depguard
+    - funcorder
+    - funlen
+    - mnd
+    - varnamelen
+    - wrapcheck
+    - exhaustruct
+    - paralleltest
+    - godot
+    - godox
+    - testpackage
+    - canonicalheader
+    - tagliatelle
+    - noinlineerr
+    - ireturn
+    - gochecknoinits
+    - nonamedreturns
+    - gomoddirectives # TODO can this be re-enabled?
+
+  settings:
+    revive:
+      rules:
+        - name: exported
+          disabled: true # TODO this is nice to enable for an SDK
+

.golangci.yml

@@ -2,6 +2,10 @@ TEST_PACKAGES := ./... ./godeltaprof/compat/... ./godeltaprof/...
 GO ?= go
 GOTIP ?= gotip
 
+GOLANGCI_LINT_VERSION ?= v2.2.2
+TOOLS_DIR := $(CURDIR)/.tools
+GOLANGCI_LINT := $(TOOLS_DIR)/golangci-lint
+
 .PHONY: test
 test:
 	$(GO) test -race $(shell $(GO) list $(TEST_PACKAGES) | grep -v /example)
@@ -22,3 +26,20 @@ gotip/fix:
 	cd godeltaprof/compat/ && $(GOTIP) get -v golang.org/x/[email protected]
 	git --no-pager diff
 	! git diff | grep toolchain
+
+.PHONY: install-lint
+install-lint:
+	@ mkdir -p $(TOOLS_DIR)
+	@ GOBIN=$(TOOLS_DIR) $(GO) install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@$(GOLANGCI_LINT_VERSION)
+
+.PHONY: lint
+lint: install-lint
+	$(GOLANGCI_LINT) run
+	cd godeltaprof && $(GOLANGCI_LINT) run
+	cd godeltaprof/compat && $(GOLANGCI_LINT) run
+
+.PHONY: examples
+examples:
+	 go build example/http/main.go
+	 go build example/simple/main.go
+	 go build example/timing/timing.go

Makefile

@@ -102,6 +102,7 @@ func Start(cfg Config) (*Profiler, error) {
 func (p *Profiler) Stop() error {
 	p.session.Stop()
 	p.uploader.Stop()
+
 	return nil
 }
 
@@ -112,7 +113,7 @@ func (p *Profiler) Flush(wait bool) {
 
 type LabelSet = pprof.LabelSet
 
-var Labels = pprof.Labels
+var Labels = pprof.Labels //nolint:gochecknoglobals
 
 func TagWrapper(ctx context.Context, labels LabelSet, cb func(context.Context)) {
 	pprof.Do(ctx, labels, func(c context.Context) { cb(c) })

api.go

@@ -2,14 +2,15 @@ package pyroscope
 
 import (
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestProfilerStartStop(t *testing.T) {
 	profiler, err := Start(Config{
 		ApplicationName: "test",
 	})
-	if err != nil {
-		t.Fatal(err)
-	}
-	profiler.Stop()
+	require.NoError(t, err)
+	err = profiler.Stop()
+	require.NoError(t, err)
 }

api_test.go

@@ -2,7 +2,7 @@ package pyroscope
 
 import (
 	"bytes"
-	"fmt"
+	"errors"
 	"io"
 	"time"
 
@@ -50,12 +50,14 @@ func newEvent(typ eventType) event {
 
 func (e event) send(c chan<- event) error {
 	c <- e
+
 	return <-e.done
 }
 
 func newStartEvent(w io.Writer) event {
 	e := newEvent(startEvent)
 	e.w = w
+
 	return e
 }
 
@@ -66,6 +68,7 @@ func newCPUProfileCollector(
 	period time.Duration,
 ) *cpuProfileCollector {
 	buf := bytes.NewBuffer(make([]byte, 0, 1<<10))
+
 	return &cpuProfileCollector{
 		name:      name,
 		dur:       period,
@@ -105,6 +108,7 @@ func (c *cpuProfileCollector) Start() {
 					d = c.dur
 				}
 				t.Reset(d)
+
 				continue
 			}
 			t.Reset(c.dur)
@@ -125,6 +129,7 @@ func (c *cpuProfileCollector) Start() {
 			c.collector.StopCPUProfile()
 			c.upload()
 			close(c.done)
+
 			return
 
 		case e := <-c.events:
@@ -145,7 +150,7 @@ func (c *cpuProfileCollector) handleEvent(e event) {
 		if c.started { // Misuse.
 			// Just to avoid interruption of the background
 			// profiling that will fail immediately.
-			err = fmt.Errorf("cpu profiling already started")
+			err = errAlreadyStarted
 		} else {
 			err = c.reset(e.w)
 			c.started = err == nil
@@ -161,7 +166,7 @@ func (c *cpuProfileCollector) handleEvent(e event) {
 		if c.started {
 			// Flush can't be done if StartCPUProfile is called,
 			// as we'd need stopping the foreground collector first.
-			err = fmt.Errorf("flush rejected: cpu profiling is in progress")
+			err = errFlushRejected
 		} else {
 			err = c.reset(nil)
 		}
@@ -184,6 +189,7 @@ func (c *cpuProfileCollector) Stop() {
 
 func (c *cpuProfileCollector) StartCPUProfile(w io.Writer) error {
 	c.logger.Debugf("cpu profile collector interrupted with StartCPUProfile")
+
 	return newStartEvent(w).send(c.events)
 }
 
@@ -206,12 +212,15 @@ func (c *cpuProfileCollector) reset(w io.Writer) error {
 		d = io.MultiWriter(d, w)
 	}
 	c.timeStarted = time.Now()
+
 	if err := c.collector.StartCPUProfile(d); err != nil {
 		c.logger.Errorf("failed to start CPU profiling: %v", err)
 		c.timeStarted = time.Time{}
 		c.buf.Reset()
+
 		return err
 	}
+
 	return nil
 }
 
@@ -236,3 +245,8 @@ func (c *cpuProfileCollector) upload() {
 	})
 	c.buf.Reset()
 }
+
+var (
+	errAlreadyStarted = errors.New("cpu profiling already started")
+	errFlushRejected  = errors.New("flush rejected: cpu profiling is in progress")
+)

collector.go

@@ -29,6 +29,7 @@ func Test_StartCPUProfile_interrupts_background_profiling(t *testing.T) {
 	// Try to interrupt it with StartCPUProfile.
 	start := collector.waitStartCPUProfile()
 	stop := collector.waitStopCPUProfile()
+
 	if err := c.StartCPUProfile(io.Discard); err != nil {
 		t.Fatal("failed to start CPU profiling")
 	}
@@ -77,6 +78,7 @@ func Test_StartCPUProfile_blocks_Stop(t *testing.T) {
 	// Try to interrupt it with StartCPUProfile.
 	start := collector.waitStartCPUProfile()
 	stop := collector.waitStopCPUProfile()
+
 	if err := c.StartCPUProfile(io.Discard); err != nil {
 		t.Fatal("failed to start CPU profiling")
 	}
@@ -102,6 +104,7 @@ func Test_StartCPUProfile_blocks_Stop(t *testing.T) {
 
 type mockCollector struct {
 	sync.Mutex
+
 	start chan struct{}
 	stop  chan struct{}
 }
@@ -111,6 +114,7 @@ func (m *mockCollector) waitStartCPUProfile() <-chan struct{} {
 	c := make(chan struct{})
 	m.start = c
 	m.Unlock()
+
 	return c
 }
 
@@ -119,6 +123,7 @@ func (m *mockCollector) waitStopCPUProfile() <-chan struct{} {
 	c := make(chan struct{})
 	m.stop = c
 	m.Unlock()
+
 	return c
 }
 
@@ -129,6 +134,7 @@ func (m *mockCollector) StartCPUProfile(_ io.Writer) error {
 		m.start = nil
 	}
 	m.Unlock()
+
 	return nil
 }