diff --git a/.github/workflows/golang-lint.yml b/.github/workflows/go-lint.yml
similarity index 93%
rename from .github/workflows/golang-lint.yml
rename to .github/workflows/go-lint.yml
index b091ab18..faa14770 100644
--- a/.github/workflows/golang-lint.yml
+++ b/.github/workflows/go-lint.yml
@@ -1,7 +1,7 @@
-name: golang-lint
-#     ~~~~~~~~~~~
-# https://github.com/kunitsucom/util.go/workflows/golang-lint/badge.svg
-#                                                 ~~~~~~~~~~~
+name: go-lint
+#     ~~~~~~~
+# https://github.com/kunitsucom/util.go/workflows/go-lint/badge.svg
+#                                                 ~~~~~~~
 
 on:
   push:
@@ -40,7 +40,7 @@ defaults:
     shell: bash
 
 jobs:
-  golang-lint: # NOTE: for Branch protection rule `Status checks that are required.`
+  go-lint: # NOTE: for Branch protection rule `Status checks that are required.`
     runs-on: ubuntu-latest # ref. https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-syntax-for-github-actions#jobsjob_idruns-on
     steps:
       - uses: actions/checkout@v3
diff --git a/.github/workflows/golang-test.yml b/.github/workflows/go-test.yml
similarity index 93%
rename from .github/workflows/golang-test.yml
rename to .github/workflows/go-test.yml
index c65a779b..bb3197ed 100644
--- a/.github/workflows/golang-test.yml
+++ b/.github/workflows/go-test.yml
@@ -1,7 +1,7 @@
-name: golang-test
-#     ~~~~~~~~~~~
-# https://github.com/kunitsucom/util.go/workflows/golang-test/badge.svg
-#                                                 ~~~~~~~~~~~
+name: go-test
+#     ~~~~~~~
+# https://github.com/kunitsucom/util.go/workflows/go-test/badge.svg
+#                                                 ~~~~~~~
 
 on:
   push:
@@ -40,7 +40,7 @@ defaults:
     shell: bash
 
 jobs:
-  golang-test: # NOTE: for Branch protection rule `Status checks that are required.`
+  go-test: # NOTE: for Branch protection rule `Status checks that are required.`
     runs-on: ubuntu-latest # ref. https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-syntax-for-github-actions#jobsjob_idruns-on
     steps:
       - uses: actions/checkout@v3
diff --git a/.golangci.yml b/.golangci.yml
index dade5bd1..11296807 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -19,7 +19,6 @@ linters:
     - ifshort # for readability
     - interfacer # deprecated https://github.com/mvdan/interfacer
     - interfacebloat # unnecessary
-    - ireturn # TODO: enable
     - lll # unnecessary
     - maligned # deprecated https://github.com/mdempsky/maligned
     - nlreturn # ignore "return with no blank line before"
diff --git a/archive/zip/add.go b/archive/zip/add.go
index dd531e8b..b57beb0e 100644
--- a/archive/zip/add.go
+++ b/archive/zip/add.go
@@ -9,20 +9,21 @@ import (
 )
 
 type (
-	AddFileToZipOption     interface{ apply(*addFileToZipConfig) }
-	addFileToZipOptionFunc func(*addFileToZipConfig)
-)
+	AddFileToZipOption interface{ apply(*addFileToZipConfig) }
 
-func (f addFileToZipOptionFunc) apply(cfg *addFileToZipConfig) { f(cfg) }
+	addFileToZipDecompressionBombLimit int64
+)
 
 type addFileToZipConfig struct {
 	decompressionBombLimit int64
 }
 
-func AddFileToZipWithDecompressionBombLimit(decompressionBombLimit int64) AddFileToZipOption {
-	return addFileToZipOptionFunc(func(cfg *addFileToZipConfig) {
-		cfg.decompressionBombLimit = decompressionBombLimit
-	})
+func (f addFileToZipDecompressionBombLimit) apply(cfg *addFileToZipConfig) {
+	cfg.decompressionBombLimit = int64(f)
+}
+
+func WithAddFileToZipDecompressionBombLimit(decompressionBombLimit int64) AddFileToZipOption { //nolint:ireturn
+	return addFileToZipDecompressionBombLimit(decompressionBombLimit)
 }
 
 // AddFileToZip is a function to add a file to an existing zip file.
diff --git a/archive/zip/zip.go b/archive/zip/zip.go
index 02c5434b..b20cd3ae 100644
--- a/archive/zip/zip.go
+++ b/archive/zip/zip.go
@@ -14,27 +14,30 @@ import (
 
 var ErrDoNotUnzipAFileAtRiskOfZipSlip = errors.New("zipz: do not unzip a file at risk of zip slip")
 
-type zipDirConfig struct {
-	walkHandler      func(path string, info os.FileInfo, err error) error
-	pathInZipHandler func(path string) string
-}
-
-type ZipDirOption interface{ apply(*zipDirConfig) }
+type (
+	zipDirConfig struct {
+		walkFunc             func(path string, info os.FileInfo, err error) error
+		pathInZipHandlerFunc func(path string) string
+	}
 
-type zipDirOptionFunc func(*zipDirConfig)
+	ZipDirOption interface{ apply(*zipDirConfig) }
 
-func (f zipDirOptionFunc) apply(cfg *zipDirConfig) { f(cfg) }
+	zipDirOptionWalkFunc struct {
+		f func(path string, info os.FileInfo, err error) error
+	}
+	zipDirOptionPathInZipHandlerFunc struct {
+		f func(path string) string
+	}
+)
 
-func ZipDirWithWalkHandler(f func(path string, info os.FileInfo, err error) error) ZipDirOption {
-	return zipDirOptionFunc(func(cfg *zipDirConfig) {
-		cfg.walkHandler = f
-	})
+func (f zipDirOptionWalkFunc) apply(cfg *zipDirConfig) { cfg.walkFunc = f.f }
+func WithZipDirOptionWalkFunc(f func(path string, info os.FileInfo, err error) error) ZipDirOption { //nolint:ireturn
+	return zipDirOptionWalkFunc{f}
 }
 
-func ZipDirWithPathInZipHandler(f func(path string) string) ZipDirOption {
-	return zipDirOptionFunc(func(cfg *zipDirConfig) {
-		cfg.pathInZipHandler = f
-	})
+func (f zipDirOptionPathInZipHandlerFunc) apply(cfg *zipDirConfig) { cfg.pathInZipHandlerFunc = f.f }
+func WithZipDirOptionPathInZipHandlerFunc(f func(path string) string) ZipDirOption { //nolint:ireturn
+	return zipDirOptionPathInZipHandlerFunc{f}
 }
 
 //nolint:cyclop
@@ -48,8 +51,8 @@ func ZipDir(dst io.Writer, srcDir string, opts ...ZipDirOption) error {
 	defer zipWriter.Close()
 
 	if err := filepath.Walk(srcDir, func(path string, info os.FileInfo, err error) error {
-		if cfg.walkHandler != nil {
-			if err := cfg.walkHandler(path, info, err); err != nil {
+		if cfg.walkFunc != nil {
+			if err := cfg.walkFunc(path, info, err); err != nil {
 				return err
 			}
 		}
@@ -67,8 +70,8 @@ func ZipDir(dst io.Writer, srcDir string, opts ...ZipDirOption) error {
 		defer file.Close()
 
 		pathInZip := cleaned
-		if cfg.pathInZipHandler != nil {
-			pathInZip = cfg.pathInZipHandler(pathInZip)
+		if cfg.pathInZipHandlerFunc != nil {
+			pathInZip = cfg.pathInZipHandlerFunc(pathInZip)
 		}
 		f, err := zipWriter.Create(pathInZip)
 		if err != nil {
@@ -87,20 +90,24 @@ func ZipDir(dst io.Writer, srcDir string, opts ...ZipDirOption) error {
 	return nil
 }
 
-type unzipFileConfig struct {
-	unzipFileFileInZipHandler func(zipfile *zip.File, dstDir string) error
-}
+type (
+	unzipFileConfig struct {
+		unzipFileFileInZipHandler func(zipfile *zip.File, dstDir string) error
+	}
 
-type UnzipFileOption interface{ apply(*unzipFileConfig) }
+	UnzipFileOption interface{ apply(*unzipFileConfig) }
 
-type unzipFileOptionFunc func(*unzipFileConfig)
+	unzipFileOptionFileInZipHandler struct {
+		f func(zipfile *zip.File, dstDir string) error
+	}
+)
 
-func (f unzipFileOptionFunc) apply(cfg *unzipFileConfig) { f(cfg) }
+func (f unzipFileOptionFileInZipHandler) apply(cfg *unzipFileConfig) {
+	cfg.unzipFileFileInZipHandler = f.f
+}
 
-func UnzipFileWithFileInZipHandler(f func(zipfile *zip.File, dstDir string) error) UnzipFileOption {
-	return unzipFileOptionFunc(func(cfg *unzipFileConfig) {
-		cfg.unzipFileFileInZipHandler = f
-	})
+func WithUnzipFileOptionFileInZipHandler(f func(zipfile *zip.File, dstDir string) error) UnzipFileOption { //nolint:ireturn
+	return unzipFileOptionFileInZipHandler{f}
 }
 
 func UnzipFile(srcZipFilePath, dstDir string, opts ...UnzipFileOption) (paths []string, err error) {
diff --git a/cache/cache.go b/cache/cache.go
index 3e584d9b..86b553d1 100644
--- a/cache/cache.go
+++ b/cache/cache.go
@@ -80,17 +80,17 @@ func (s *Store[T]) StopRefresher() {
 
 // GetOrSet gets cache value T, or set the value T that returns getValue.
 // If getValue does not return err, cache the value T.
-func (s *Store[T]) GetOrSet(key string, getValue func() (T, error)) (T, error) {
+func (s *Store[T]) GetOrSet(key string, getValue func() (T, error)) (T, error) { //nolint:ireturn
 	return s.GetOrSetWithTTL(key, getValue, s.defaultTTL)
 }
 
 // GetOrSet gets cache value T, or set the value T that returns getValue with TTL.
 // If getValue does not return err, cache the value T.
-func (s *Store[T]) GetOrSetWithTTL(key string, getValue func() (T, error), ttl time.Duration) (T, error) {
+func (s *Store[T]) GetOrSetWithTTL(key string, getValue func() (T, error), ttl time.Duration) (T, error) { //nolint:ireturn
 	return s.getOrSet(key, getValue, ttl, time.Now())
 }
 
-func (s *Store[T]) getOrSet(key string, getValue func() (T, error), ttl time.Duration, now time.Time) (T, error) {
+func (s *Store[T]) getOrSet(key string, getValue func() (T, error), ttl time.Duration, now time.Time) (T, error) { //nolint:ireturn
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
diff --git a/database/sql/queryer.go b/database/sql/queryer.go
index 2a96de55..c882ded7 100644
--- a/database/sql/queryer.go
+++ b/database/sql/queryer.go
@@ -20,18 +20,21 @@ type QueryerContext interface {
 	QueryRowContext(ctx context.Context, dst interface{}, query string, args ...interface{}) error
 }
 
-type queryerContext struct {
-	sqlQueryer sqlQueryerContext
+type (
+	queryerContext struct {
+		sqlQueryer sqlQueryerContext
+		// Options
+		structTag string
+	}
 
-	structTag string
-}
+	NewDBOption interface{ apply(*queryerContext) }
 
-type NewDBOption func(qc *queryerContext)
+	newDBOptionStructTag string
+)
 
-func WithNewDBOptionStructTag(structTag string) NewDBOption {
-	return func(qc *queryerContext) {
-		qc.structTag = structTag
-	}
+func (f newDBOptionStructTag) apply(qc *queryerContext) { qc.structTag = string(f) }
+func WithNewDBOptionStructTag(structTag string) NewDBOption { //nolint:ireturn
+	return newDBOptionStructTag(structTag)
 }
 
 func NewDB(db sqlQueryerContext, opts ...NewDBOption) QueryerContext { //nolint:ireturn
@@ -47,7 +50,7 @@ func newDB(db sqlQueryerContext, opts ...NewDBOption) *queryerContext {
 	}
 
 	for _, opt := range opts {
-		opt(qc)
+		opt.apply(qc)
 	}
 
 	return qc
diff --git a/discard/discard.go b/discard/discard.go
index f268889e..f74ed962 100644
--- a/discard/discard.go
+++ b/discard/discard.go
@@ -4,22 +4,22 @@ func Discard(discard any) {
 	_ = discard
 }
 
-func One[T any](v1 T, _ any) T {
+func One[T any](v1 T, _ any) T { //nolint:ireturn
 	return v1
 }
 
-func Two[T1, T2 any](v1 T1, v2 T2, _ any) (T1, T2) {
+func Two[T1, T2 any](v1 T1, v2 T2, _ any) (T1, T2) { //nolint:ireturn
 	return v1, v2
 }
 
-func Three[T1, T2, T3 any](v1 T1, v2 T2, v3 T3, _ any) (T1, T2, T3) {
+func Three[T1, T2, T3 any](v1 T1, v2 T2, v3 T3, _ any) (T1, T2, T3) { //nolint:ireturn
 	return v1, v2, v3
 }
 
-func Four[T1, T2, T3, T4 any](v1 T1, v2 T2, v3 T3, v4 T4, _ any) (T1, T2, T3, T4) {
+func Four[T1, T2, T3, T4 any](v1 T1, v2 T2, v3 T3, v4 T4, _ any) (T1, T2, T3, T4) { //nolint:ireturn
 	return v1, v2, v3, v4
 }
 
-func Five[T1, T2, T3, T4, T5 any](v1 T1, v2 T2, v3 T3, v4 T4, v5 T5, _ any) (T1, T2, T3, T4, T5) {
+func Five[T1, T2, T3, T4, T5 any](v1 T1, v2 T2, v3 T3, v4 T4, v5 T5, _ any) (T1, T2, T3, T4, T5) { //nolint:ireturn
 	return v1, v2, v3, v4, v5
 }
diff --git a/must/must.go b/must/must.go
index c626d2e6..9db8480f 100644
--- a/must/must.go
+++ b/must/must.go
@@ -6,7 +6,7 @@ func Must(err error) {
 	}
 }
 
-func One[T any](v T, err error) T {
+func One[T any](v T, err error) T { //nolint:ireturn
 	if err != nil {
 		panic(err)
 	}
@@ -14,7 +14,7 @@ func One[T any](v T, err error) T {
 	return v
 }
 
-func Two[T1, T2 any](v1 T1, v2 T2, err error) (T1, T2) {
+func Two[T1, T2 any](v1 T1, v2 T2, err error) (T1, T2) { //nolint:ireturn
 	if err != nil {
 		panic(err)
 	}
@@ -22,7 +22,7 @@ func Two[T1, T2 any](v1 T1, v2 T2, err error) (T1, T2) {
 	return v1, v2
 }
 
-func Three[T1, T2, T3 any](v1 T1, v2 T2, v3 T3, err error) (T1, T2, T3) {
+func Three[T1, T2, T3 any](v1 T1, v2 T2, v3 T3, err error) (T1, T2, T3) { //nolint:ireturn
 	if err != nil {
 		panic(err)
 	}
@@ -30,7 +30,7 @@ func Three[T1, T2, T3 any](v1 T1, v2 T2, v3 T3, err error) (T1, T2, T3) {
 	return v1, v2, v3
 }
 
-func Four[T1, T2, T3, T4 any](v1 T1, v2 T2, v3 T3, v4 T4, err error) (T1, T2, T3, T4) {
+func Four[T1, T2, T3, T4 any](v1 T1, v2 T2, v3 T3, v4 T4, err error) (T1, T2, T3, T4) { //nolint:ireturn
 	if err != nil {
 		panic(err)
 	}
@@ -38,7 +38,7 @@ func Four[T1, T2, T3, T4 any](v1 T1, v2 T2, v3 T3, v4 T4, err error) (T1, T2, T3
 	return v1, v2, v3, v4
 }
 
-func Five[T1, T2, T3, T4, T5 any](v1 T1, v2 T2, v3 T3, v4 T4, v5 T5, err error) (T1, T2, T3, T4, T5) {
+func Five[T1, T2, T3, T4, T5 any](v1 T1, v2 T2, v3 T3, v4 T4, v5 T5, err error) (T1, T2, T3, T4, T5) { //nolint:ireturn
 	if err != nil {
 		panic(err)
 	}
diff --git a/net/http/header.go b/net/http/header.go
index 28645d86..201151f4 100644
--- a/net/http/header.go
+++ b/net/http/header.go
@@ -13,23 +13,23 @@ type headerBuilder struct {
 	header http.Header
 }
 
-func NewHeaderBuilder() HeaderBuilder {
+func NewHeaderBuilder() HeaderBuilder { //nolint:ireturn
 	return &headerBuilder{
 		header: make(http.Header),
 	}
 }
 
-func (h *headerBuilder) Add(key, value string) HeaderBuilder {
+func (h *headerBuilder) Add(key, value string) HeaderBuilder { //nolint:ireturn
 	h.header.Add(key, value)
 	return h
 }
 
-func (h *headerBuilder) Set(key, value string) HeaderBuilder {
+func (h *headerBuilder) Set(key, value string) HeaderBuilder { //nolint:ireturn
 	h.header.Set(key, value)
 	return h
 }
 
-func (h *headerBuilder) Merge(header http.Header) HeaderBuilder {
+func (h *headerBuilder) Merge(header http.Header) HeaderBuilder { //nolint:ireturn
 	for key, values := range header {
 		for _, value := range values {
 			h.Add(key, value)
diff --git a/net/http/realip.go b/net/http/realip.go
index 835570af..10b928a1 100644
--- a/net/http/realip.go
+++ b/net/http/realip.go
@@ -88,23 +88,32 @@ func ContextWithXRealIP(parent context.Context, xRealIP string) context.Context
 	return context.WithValue(parent, keyXRealIP, xRealIP)
 }
 
-type xRealIPHandlerConfig struct {
-	//nolint:revive,stylecheck
-	set_real_ip_from []*net.IPNet
-	//nolint:revive,stylecheck
-	real_ip_header string
-	//nolint:revive,stylecheck
-	real_ip_recursive bool
-
-	clientIPAddressHeader string
-}
+type (
+	xRealIPHandlerConfig struct {
+		//nolint:revive,stylecheck
+		set_real_ip_from []*net.IPNet
+		//nolint:revive,stylecheck
+		real_ip_header string
+		//nolint:revive,stylecheck
+		real_ip_recursive bool
+
+		clientIPAddressHeader string
+	}
 
-type XRealIPHandlerOption interface {
-	apply(*xRealIPHandlerConfig)
+	NewXRealIPHandlerOption interface {
+		apply(*xRealIPHandlerConfig)
+	}
+
+	newXRealIPHandlerOptionClientIPAddressHeader string
+)
+
+func (f newXRealIPHandlerOptionClientIPAddressHeader) apply(cfg *xRealIPHandlerConfig) {
+	cfg.clientIPAddressHeader = string(f)
 }
-type xRealIPHandlerOption func(h *xRealIPHandlerConfig)
 
-func (f xRealIPHandlerOption) apply(h *xRealIPHandlerConfig) { f(h) }
+func WithNewXRealIPHandlerOptionClientIPAddressHeader(header string) NewXRealIPHandlerOption { //nolint:ireturn
+	return newXRealIPHandlerOptionClientIPAddressHeader(header)
+}
 
 // NewXRealIPHandler returns realip handler that appends X-Real-IP header.
 // If set_real_ip_from is X-Forwarded-For and it has below values:
@@ -124,7 +133,7 @@ func (f xRealIPHandlerOption) apply(h *xRealIPHandlerConfig) { f(h) }
 //	)
 //
 //nolint:revive,stylecheck
-func NewXRealIPHandler(set_real_ip_from []*net.IPNet, real_ip_header string, real_ip_recursive bool, opts ...XRealIPHandlerOption) func(next http.Handler) http.Handler {
+func NewXRealIPHandler(set_real_ip_from []*net.IPNet, real_ip_header string, real_ip_recursive bool, opts ...NewXRealIPHandlerOption) func(next http.Handler) http.Handler {
 	c := &xRealIPHandlerConfig{
 		set_real_ip_from:      set_real_ip_from,
 		real_ip_header:        real_ip_header,
@@ -147,12 +156,6 @@ func NewXRealIPHandler(set_real_ip_from []*net.IPNet, real_ip_header string, rea
 	}
 }
 
-func WithClientIPAddressHeader(header string) XRealIPHandlerOption {
-	return xRealIPHandlerOption(func(h *xRealIPHandlerConfig) {
-		h.clientIPAddressHeader = header
-	})
-}
-
 func RemoteIP(r *http.Request) string {
 	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
 	return ip
diff --git a/net/http/realip_test.go b/net/http/realip_test.go
index 5b72bdb2..b1c300c5 100644
--- a/net/http/realip_test.go
+++ b/net/http/realip_test.go
@@ -37,7 +37,7 @@ func TestNewXRealIPHandler(t *testing.T) {
 			httpz.DefaultSetRealIPFrom(),
 			httpz.HeaderXForwardedFor,
 			true,
-			httpz.WithClientIPAddressHeader(header),
+			httpz.WithNewXRealIPHandlerOptionClientIPAddressHeader(header),
 		)
 
 		r := httptest.NewRequest(http.MethodPost, "http://util.go/net/httpz", bytes.NewBufferString("test_request_body"))
diff --git a/slices/slices.go b/slices/slices.go
index 787b5b09..673274d7 100644
--- a/slices/slices.go
+++ b/slices/slices.go
@@ -111,7 +111,7 @@ func Select[Source, Selected any](s []Source, generator func(index int, source S
 	return gen
 }
 
-func First[T any](s []T) T {
+func First[T any](s []T) T { //nolint:ireturn
 	if len(s) == 0 {
 		var zero T
 		return zero
@@ -119,7 +119,7 @@ func First[T any](s []T) T {
 	return s[0]
 }
 
-func Last[T any](s []T) T {
+func Last[T any](s []T) T { //nolint:ireturn
 	if len(s) == 0 {
 		var zero T
 		return zero