[chore]: enable gofumpt linter

.golangci.yml

@@ -143,7 +143,7 @@ linters:
     - errcheck
     - errorlint
     - gocritic
-    - gofmt
+    - gofumpt
     - goimports
     - gosec
     - govet

Makefile.Common

@@ -27,6 +27,7 @@ CHECKFILE    := $(TOOLS_BIN_DIR)/checkfile
 CHLOGGEN     := $(TOOLS_BIN_DIR)/chloggen
 CROSSLINK    := $(TOOLS_BIN_DIR)/crosslink
 ENVSUBST     := $(TOOLS_BIN_DIR)/envsubst
+GOFUMPT      := $(TOOLS_BIN_DIR)/gofumpt
 GOIMPORTS    := $(TOOLS_BIN_DIR)/goimports
 GOVULNCHECK  := $(TOOLS_BIN_DIR)/govulncheck
 LINT         := $(TOOLS_BIN_DIR)/golangci-lint
@@ -60,8 +61,8 @@ benchmark:
 	$(GOTEST) -bench=. -run=notests ./... | tee benchmark.txt
 
 .PHONY: fmt
-fmt: $(GOIMPORTS)
-	gofmt -w -s ./
+fmt: $(GOFUMPT) $(GOIMPORTS)
+	$(GOFUMPT) -l -w .
 	$(GOIMPORTS) -w  -local go.opentelemetry.io/collector ./
 
 .PHONY: tidy

client/doc_test.go

@@ -77,6 +77,7 @@ func (e *exampleAuthData) GetAttribute(key string) any {
 	}
 	return nil
 }
+
 func (e *exampleAuthData) GetAttributeNames() []string {
 	return []string{"username"}
 }

cmd/builder/internal/builder/config.go

@@ -17,14 +17,14 @@ import (
 	"go.uber.org/zap"
 )
 
-const defaultBetaOtelColVersion = "v0.114.0"
-const defaultStableOtelColVersion = "v1.17.0"
-
-var (
-	// errMissingGoMod indicates an empty gomod field
-	errMissingGoMod = errors.New("missing gomod specification for module")
+const (
+	defaultBetaOtelColVersion   = "v0.114.0"
+	defaultStableOtelColVersion = "v1.17.0"
 )
 
+// errMissingGoMod indicates an empty gomod field
+var errMissingGoMod = errors.New("missing gomod specification for module")
+
 // Config holds the builder's configuration
 type Config struct {
 	Logger *zap.Logger

cmd/builder/internal/builder/main.go

@@ -77,7 +77,7 @@ func Generate(cfg *Config) error {
 
 	// if the file does not exist, try to create it
 	if _, err := os.Stat(cfg.Distribution.OutputPath); os.IsNotExist(err) {
-		if err = os.Mkdir(cfg.Distribution.OutputPath, 0750); err != nil {
+		if err = os.Mkdir(cfg.Distribution.OutputPath, 0o750); err != nil {
 			return fmt.Errorf("failed to create output path: %w", err)
 		}
 	} else if err != nil {
@@ -109,7 +109,7 @@ func Compile(cfg *Config) error {
 
 	cfg.Logger.Info("Compiling")
 
-	var ldflags = "-s -w"
+	ldflags := "-s -w"
 
 	args := []string{"build", "-trimpath", "-o", cfg.Distribution.Name}
 	if cfg.Distribution.DebugCompilation {

cmd/builder/internal/builder/main_test.go

@@ -37,77 +37,75 @@ require (
 	modulePrefix = "go.opentelemetry.io/collector"
 )
 
-var (
-	replaceModules = []string{
-		"",
-		"/component",
-		"/component/componenttest",
-		"/component/componentstatus",
-		"/client",
-		"/config/configauth",
-		"/config/configcompression",
-		"/config/configgrpc",
-		"/config/confighttp",
-		"/config/confignet",
-		"/config/configopaque",
-		"/config/configretry",
-		"/config/configtelemetry",
-		"/config/configtls",
-		"/config/internal",
-		"/confmap",
-		"/confmap/provider/envprovider",
-		"/confmap/provider/fileprovider",
-		"/confmap/provider/httpprovider",
-		"/confmap/provider/httpsprovider",
-		"/confmap/provider/yamlprovider",
-		"/consumer",
-		"/consumer/consumererror",
-		"/consumer/consumererror/consumererrorprofiles",
-		"/consumer/consumerprofiles",
-		"/consumer/consumertest",
-		"/connector",
-		"/connector/connectortest",
-		"/connector/connectorprofiles",
-		"/exporter",
-		"/exporter/debugexporter",
-		"/exporter/exporterprofiles",
-		"/exporter/exportertest",
-		"/exporter/exporterhelper/exporterhelperprofiles",
-		"/exporter/nopexporter",
-		"/exporter/otlpexporter",
-		"/exporter/otlphttpexporter",
-		"/extension",
-		"/extension/auth",
-		"/extension/auth/authtest",
-		"/extension/experimental/storage",
-		"/extension/extensioncapabilities",
-		"/extension/extensiontest",
-		"/extension/zpagesextension",
-		"/featuregate",
-		"/internal/memorylimiter",
-		"/internal/fanoutconsumer",
-		"/internal/sharedcomponent",
-		"/otelcol",
-		"/pipeline",
-		"/pipeline/pipelineprofiles",
-		"/processor",
-		"/processor/processortest",
-		"/processor/batchprocessor",
-		"/processor/memorylimiterprocessor",
-		"/processor/processorprofiles",
-		"/receiver",
-		"/receiver/nopreceiver",
-		"/receiver/otlpreceiver",
-		"/receiver/receiverprofiles",
-		"/receiver/receivertest",
-		"/pdata",
-		"/pdata/testdata",
-		"/pdata/pprofile",
-		"/scraper",
-		"/semconv",
-		"/service",
-	}
-)
+var replaceModules = []string{
+	"",
+	"/component",
+	"/component/componenttest",
+	"/component/componentstatus",
+	"/client",
+	"/config/configauth",
+	"/config/configcompression",
+	"/config/configgrpc",
+	"/config/confighttp",
+	"/config/confignet",
+	"/config/configopaque",
+	"/config/configretry",
+	"/config/configtelemetry",
+	"/config/configtls",
+	"/config/internal",
+	"/confmap",
+	"/confmap/provider/envprovider",
+	"/confmap/provider/fileprovider",
+	"/confmap/provider/httpprovider",
+	"/confmap/provider/httpsprovider",
+	"/confmap/provider/yamlprovider",
+	"/consumer",
+	"/consumer/consumererror",
+	"/consumer/consumererror/consumererrorprofiles",
+	"/consumer/consumerprofiles",
+	"/consumer/consumertest",
+	"/connector",
+	"/connector/connectortest",
+	"/connector/connectorprofiles",
+	"/exporter",
+	"/exporter/debugexporter",
+	"/exporter/exporterprofiles",
+	"/exporter/exportertest",
+	"/exporter/exporterhelper/exporterhelperprofiles",
+	"/exporter/nopexporter",
+	"/exporter/otlpexporter",
+	"/exporter/otlphttpexporter",
+	"/extension",
+	"/extension/auth",
+	"/extension/auth/authtest",
+	"/extension/experimental/storage",
+	"/extension/extensioncapabilities",
+	"/extension/extensiontest",
+	"/extension/zpagesextension",
+	"/featuregate",
+	"/internal/memorylimiter",
+	"/internal/fanoutconsumer",
+	"/internal/sharedcomponent",
+	"/otelcol",
+	"/pipeline",
+	"/pipeline/pipelineprofiles",
+	"/processor",
+	"/processor/processortest",
+	"/processor/batchprocessor",
+	"/processor/memorylimiterprocessor",
+	"/processor/processorprofiles",
+	"/receiver",
+	"/receiver/nopreceiver",
+	"/receiver/otlpreceiver",
+	"/receiver/receiverprofiles",
+	"/receiver/receivertest",
+	"/pdata",
+	"/pdata/testdata",
+	"/pdata/pprofile",
+	"/scraper",
+	"/semconv",
+	"/service",
+}
 
 func newTestConfig(t testing.TB) *Config {
 	cfg, err := NewDefaultConfig()
@@ -429,14 +427,14 @@ func verifyGoMod(t *testing.T, dir string, replaceMods map[string]bool) {
 func makeModule(dir string, fileContents []byte) error {
 	// if the file does not exist, try to create it
 	if _, err := os.Stat(dir); os.IsNotExist(err) {
-		if err = os.Mkdir(dir, 0750); err != nil {
+		if err = os.Mkdir(dir, 0o750); err != nil {
 			return fmt.Errorf("failed to create output path: %w", err)
 		}
 	} else if err != nil {
 		return fmt.Errorf("failed to create output path: %w", err)
 	}
 
-	err := os.WriteFile(filepath.Clean(filepath.Join(dir, "go.mod")), fileContents, 0600)
+	err := os.WriteFile(filepath.Clean(filepath.Join(dir, "go.mod")), fileContents, 0o600)
 	if err != nil {
 		return fmt.Errorf("failed to write go.mod file: %w", err)
 	}

cmd/builder/internal/version.go

@@ -10,9 +10,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-var (
-	version = ""
-)
+var version = ""
 
 func init() {
 	// the second returned value is a boolean, which is true if the binaries are built with module support.

cmd/mdatagen/internal/command.go

@@ -75,7 +75,7 @@ func run(ymlPath string) error {
 	tmplDir := "templates"
 
 	codeDir := filepath.Join(ymlDir, "internal", md.GeneratedPackageName)
-	if err = os.MkdirAll(codeDir, 0700); err != nil {
+	if err = os.MkdirAll(codeDir, 0o700); err != nil {
 		return fmt.Errorf("unable to create output directory %q: %w", codeDir, err)
 	}
 	if md.Status != nil {
@@ -130,7 +130,7 @@ func run(ymlPath string) error {
 		return nil
 	}
 
-	if err = os.MkdirAll(filepath.Join(codeDir, "testdata"), 0700); err != nil {
+	if err = os.MkdirAll(filepath.Join(codeDir, "testdata"), 0o700); err != nil {
 		return fmt.Errorf("unable to create output directory %q: %w", filepath.Join(codeDir, "testdata"), err)
 	}
 
@@ -376,7 +376,7 @@ func inlineReplace(tmplFile string, outputFile string, md Metadata, start string
 		return err
 	}
 
-	var re = regexp.MustCompile(fmt.Sprintf("%s[\\s\\S]*%s", start, end))
+	re := regexp.MustCompile(fmt.Sprintf("%s[\\s\\S]*%s", start, end))
 	if !re.Match(readmeContents) {
 		return nil
 	}
@@ -391,7 +391,7 @@ func inlineReplace(tmplFile string, outputFile string, md Metadata, start string
 	}
 
 	s := re.ReplaceAllString(string(readmeContents), string(buf))
-	if err := os.WriteFile(outputFile, []byte(s), 0600); err != nil {
+	if err := os.WriteFile(outputFile, []byte(s), 0o600); err != nil {
 		return fmt.Errorf("failed writing %q: %w", outputFile, err)
 	}
 
@@ -416,7 +416,7 @@ func generateFile(tmplFile string, outputFile string, md Metadata, goPackage str
 		}
 	}
 
-	if err := os.WriteFile(outputFile, result, 0600); err != nil {
+	if err := os.WriteFile(outputFile, result, 0o600); err != nil {
 		return fmt.Errorf("failed writing %q: %w", outputFile, err)
 	}
 

cmd/mdatagen/internal/command_test.go

@@ -137,16 +137,16 @@ func TestRunContents(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.yml, func(t *testing.T) {
 			tmpdir := filepath.Join(t.TempDir(), "shortname")
-			err := os.MkdirAll(tmpdir, 0750)
+			err := os.MkdirAll(tmpdir, 0o750)
 			require.NoError(t, err)
 			ymlContent, err := os.ReadFile(filepath.Join("testdata", tt.yml))
 			require.NoError(t, err)
 			metadataFile := filepath.Join(tmpdir, "metadata.yaml")
-			require.NoError(t, os.WriteFile(metadataFile, ymlContent, 0600))
+			require.NoError(t, os.WriteFile(metadataFile, ymlContent, 0o600))
 			require.NoError(t, os.WriteFile(filepath.Join(tmpdir, "README.md"), []byte(`
 <!-- status autogenerated section -->
 foo
-<!-- end autogenerated section -->`), 0600))
+<!-- end autogenerated section -->`), 0o600))
 
 			err = run(metadataFile)
 			if tt.wantErr {
@@ -472,7 +472,7 @@ Some info about a component
 			tmpdir := t.TempDir()
 
 			readmeFile := filepath.Join(tmpdir, "README.md")
-			require.NoError(t, os.WriteFile(readmeFile, []byte(tt.markdown), 0600))
+			require.NoError(t, os.WriteFile(readmeFile, []byte(tt.markdown), 0o600))
 
 			err := inlineReplace("templates/readme.md.tmpl", readmeFile, md, statusStart, statusEnd, "metadata")
 			require.NoError(t, err)

cmd/mdatagen/internal/lint_test.go

@@ -10,7 +10,7 @@ import (
 )
 
 func TestFormatIdentifier(t *testing.T) {
-	var tests = []struct {
+	tests := []struct {
 		input    string
 		want     string
 		exported bool

cmd/mdatagen/internal/metric.go

@@ -113,6 +113,7 @@ func (m *Metric) Unmarshal(parser *confmap.Conf) error {
 	}
 	return parser.Unmarshal(m)
 }
+
 func (m Metric) Data() MetricData {
 	if m.Sum != nil {
 		return m.Sum

component/componentstatus/status_test.go

@@ -105,8 +105,10 @@ func Test_ReportStatus(t *testing.T) {
 	})
 }
 
-var _ = (component.Host)(nil)
-var _ = (Reporter)(nil)
+var (
+	_ = (component.Host)(nil)
+	_ = (Reporter)(nil)
+)
 
 type reporter struct {
 	reportStatusCalled bool

component/config_test.go

@@ -75,7 +75,7 @@ func newErrMapType() *errMapType {
 }
 
 func TestValidateConfig(t *testing.T) {
-	var tests = []struct {
+	tests := []struct {
 		name     string
 		cfg      any
 		expected error

component/identifiable_test.go

@@ -20,7 +20,7 @@ func TestMarshalText(t *testing.T) {
 
 func TestUnmarshalText(t *testing.T) {
 	validType := MustNewType("valid_type")
-	var testCases = []struct {
+	testCases := []struct {
 		name        string
 		expectedErr bool
 		expectedID  ID