Modernize codebase

Author: janos

auth.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"slices"
 	"strings"
 )
 
@@ -20,11 +21,12 @@ const basicAuthScheme string = "Basic "
 // custom Key and Secret HTTP headers, or Basic auth from Authorization header.
 // Depending on configuration of BasicAuthRealm, KeyHeaderName or SecretHeaderName,
 // it can be used as"
-//  - Basic auth handler - only BasicAuthRealm is set
-//  - single API key auth handler - only KeyHeaderName is set
-//  - single API key auth handler with Basic auth support - BasicAuthRealm and KeyHeaderName are set
-//  - public/secret API key auth handler - KeyHeaderName and SecretHeaderName are set
-//  - public/secret API key auth handler with Basic auth support - all three are set
+//   - Basic auth handler - only BasicAuthRealm is set
+//   - single API key auth handler - only KeyHeaderName is set
+//   - single API key auth handler with Basic auth support - BasicAuthRealm and KeyHeaderName are set
+//   - public/secret API key auth handler - KeyHeaderName and SecretHeaderName are set
+//   - public/secret API key auth handler with Basic auth support - all three are set
+//
 // By setting AuthorizedNetworks, this handler can authorize requests based only on
 // RemoteAddr address.
 type AuthHandler[Entity any] struct {
@@ -101,7 +103,7 @@ func getRequestIPs(r *http.Request) (ips []net.IP) {
 		}
 	}
 	if h := r.Header.Get("X-Forwarded-For"); h != "" {
-		for _, x := range strings.Split(h, ",") {
+		for x := range strings.SplitSeq(h, ",") {
 			if i := net.ParseIP(strings.TrimSpace(x)); i != nil {
 				ips = append(ips, i)
 			}
@@ -134,11 +136,9 @@ func (h AuthHandler[Entity]) authenticate(r *http.Request) (valid bool, entity E
 			ips = []net.IP{ip}
 		}
 		for _, network := range h.AuthorizedNetworks {
-			for _, ip := range ips {
-				if network.Contains(ip) {
-					valid = true
-					return
-				}
+			if slices.ContainsFunc(ips, network.Contains) {
+				valid = true
+				return
 			}
 		}
 	}

file-server/hasher.go

@@ -9,6 +9,7 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"io"
+	"slices"
 	"strings"
 )
 
@@ -45,13 +46,7 @@ func (s MD5Hasher) IsHash(h string) bool {
 	}
 	var found bool
 	for _, c := range h {
-		found = false
-		for _, m := range hexChars {
-			if c == m {
-				found = true
-				break
-			}
-		}
+		found = slices.Contains(hexChars, c)
 		if !found {
 			return false
 		}

server/server.go

@@ -207,8 +207,8 @@ func (s *Server) WithHTTP(o HTTPOptions) (err error) {
 
 	for domain := range handlers {
 		var redirectDomain string
-		if strings.HasPrefix(domain, "www.") {
-			redirectDomain = strings.TrimPrefix(domain, "www.")
+		if after, ok := strings.CutPrefix(domain, "www."); ok {
+			redirectDomain = after
 		} else {
 			redirectDomain = "www." + domain
 		}

templates/functions.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"html/template"
+	"slices"
 	"strings"
 	"time"
 )
@@ -76,10 +77,8 @@ func yearRangeFunc(year int) string {
 }
 
 func containsStringFunc(list []string, element, yes, no string) string {
-	for _, e := range list {
-		if e == element {
-			return yes
-		}
+	if slices.Contains(list, element) {
+		return yes
 	}
 	return no
 }

templates/templates.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"html/template"
 	"log/slog"
+	"maps"
 	"net/http"
 	"os"
 	"path/filepath"
@@ -101,9 +102,7 @@ func WithTemplateFromFiles(name string, files ...string) Option {
 // WithTemplatesFromFiles adds a map of templates parsed from files.
 func WithTemplatesFromFiles(ts map[string][]string) Option {
 	return func(o *Options) {
-		for name, files := range ts {
-			o.files[name] = files
-		}
+		maps.Copy(o.files, ts)
 	}
 }
 
@@ -115,9 +114,7 @@ func WithTemplateFromStrings(name string, strings ...string) Option {
 // WithTemplatesFromStrings adds a map of templates parsed from strings.
 func WithTemplatesFromStrings(ts map[string][]string) Option {
 	return func(o *Options) {
-		for name, strings := range ts {
-			o.strings[name] = strings
-		}
+		maps.Copy(o.strings, ts)
 	}
 }
 
@@ -129,9 +126,7 @@ func WithFunction(name string, fn any) Option {
 // WithFunctions adds function map to templates.
 func WithFunctions(fns template.FuncMap) Option {
 	return func(o *Options) {
-		for name, fn := range fns {
-			o.functions[name] = fn
-		}
+		maps.Copy(o.functions, fns)
 	}
 }
 
@@ -161,9 +156,7 @@ type Templates struct {
 // provided files and strings.
 func New(opts ...Option) (t *Templates, err error) {
 	functions := template.FuncMap{}
-	for name, fn := range defaultFunctions {
-		functions[name] = fn
-	}
+	maps.Copy(functions, defaultFunctions)
 	o := &Options{
 		fileFindFunc: func(f string) string {
 			return f