Naming, layout and comments: descriptive full-word names, one item per line in wrapped calls and literals, and doc comments on exported names

Short and single-letter names in application code become full words (tests
keep theirs). Wrapped calls, signatures and composite literals put one item
per line, and one-line function bodies are expanded. Exported names and
groups of constants get doc comments, and comments refer to the renamed
identifiers.

internal/logging/accesslog.go

@@ -26,32 +26,32 @@ func (r *statusRecorder) WriteHeader(code int) {
 	r.ResponseWriter.WriteHeader(code)
 }
 
-func (r *statusRecorder) Write(b []byte) (int, error) {
+func (r *statusRecorder) Write(data []byte) (int, error) {
 	if r.status == 0 {
 		r.status = http.StatusOK
 	}
-	n, err := r.ResponseWriter.Write(b)
-	r.bytes += n
-	return n, err
+	written, err := r.ResponseWriter.Write(data)
+	r.bytes += written
+	return written, err
 }
 
 // logField escapes a value for a quoted log field the way nginx does
 // (quotes, backslashes and control characters become \xHH) and uses "-"
 // for empty values.
-func logField(s string) string {
-	if s == "" {
+func logField(value string) string {
+	if value == "" {
 		return "-"
 	}
-	var b strings.Builder
-	for i := 0; i < len(s); i++ {
-		c := s[i]
-		if c == '"' || c == '\\' || c < 0x20 || c == 0x7f {
-			fmt.Fprintf(&b, "\\x%02X", c)
+	var builder strings.Builder
+	for i := 0; i < len(value); i++ {
+		char := value[i]
+		if char == '"' || char == '\\' || char < 0x20 || char == 0x7f {
+			fmt.Fprintf(&builder, "\\x%02X", char)
 		} else {
-			b.WriteByte(c)
+			builder.WriteByte(char)
 		}
 	}
-	return b.String()
+	return builder.String()
 }
 
 // clientKey attempts to produce a client host name as a key identifier to split
@@ -71,26 +71,29 @@ func clientKey(req *http.Request) string {
 func AccessLog(logger *log.Logger, combined bool, next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		start := time.Now()
-		rec := &statusRecorder{ResponseWriter: w}
-		next.ServeHTTP(rec, req)
-		if rec.status == 0 {
-			rec.status = http.StatusOK
+		recorder := &statusRecorder{
+			ResponseWriter: w,
+		}
+		next.ServeHTTP(recorder, req)
+		if recorder.status == 0 {
+			recorder.status = http.StatusOK
 		}
 
 		user := "-"
-		if u, _, ok := req.BasicAuth(); ok && u != "" {
-			user = logField(u)
+		if username, _, ok := req.BasicAuth(); ok && username != "" {
+			user = logField(username)
 		}
 		size := "-" // CLF uses "-" for an empty body
-		if rec.bytes > 0 {
-			size = strconv.Itoa(rec.bytes)
+		if recorder.bytes > 0 {
+			size = strconv.Itoa(recorder.bytes)
 		}
-		line := fmt.Sprintf(`%s - %s [%s] "%s" %d %s`,
+		line := fmt.Sprintf(
+			`%s - %s [%s] "%s" %d %s`,
 			clientKey(req),
 			user,
 			start.Format("02/Jan/2006:15:04:05 -0700"),
 			logField(req.Method+" "+req.RequestURI+" "+req.Proto),
-			rec.status,
+			recorder.status,
 			size,
 		)
 		if combined {