tools: introduce LazyBuffer abstraction of bytes.Buffer

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/tools/buffer.go

@@ -0,0 +1,72 @@
+package tools
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+// LazyBuffer is a [bytes.Buffer] that minimizes counting and error checks.
+type LazyBuffer bytes.Buffer
+
+// Sys returns the underlying [bytes.Buffer].
+func (buf *LazyBuffer) Sys() *bytes.Buffer {
+	if buf == nil {
+		return nil
+	}
+	return (*bytes.Buffer)(buf)
+}
+
+// Len tells the size in bytes of the currently stored data.
+func (buf *LazyBuffer) Len() int { return buf.Sys().Len() }
+
+// String returns the stored data as string.
+func (buf *LazyBuffer) String() string { return buf.Sys().String() }
+
+// Bytes returns the stored data as a bytes slice.
+func (buf *LazyBuffer) Bytes() []byte { return buf.Sys().Bytes() }
+
+// Write implements the standard io.Writer interface.
+func (buf *LazyBuffer) Write(b []byte) (int, error) { return buf.Sys().Write(b) }
+
+// WriteTo implements the standard WriteTo() interface.
+func (buf *LazyBuffer) WriteTo(out io.Writer) (int64, error) { return buf.Sys().WriteTo(out) }
+
+// Print appends the [fmt.Print] equivalent to the buffer.
+func (buf *LazyBuffer) Print(a ...any) error {
+	_, err := fmt.Fprint(buf.Sys(), a...)
+	return err
+}
+
+// Println appends the [fmt.Println] equivalent to the buffer.
+func (buf *LazyBuffer) Println(a ...any) error {
+	_, err := fmt.Fprintln(buf.Sys(), a...)
+	return err
+}
+
+// Printf appends the [fmt.Printf] equivalent to the buffer.
+func (buf *LazyBuffer) Printf(format string, a ...any) error {
+	_, err := fmt.Fprintf(buf.Sys(), format, a...)
+	return err
+}
+
+// WriteRunes appends the given runes as UTF-8 characters to the buffer.
+func (buf *LazyBuffer) WriteRunes(runes ...rune) {
+	for _, r := range runes {
+		_, _ = buf.Sys().WriteRune(r)
+	}
+}
+
+// WriteBytes writes the given byte arrays to the buffer.
+func (buf *LazyBuffer) WriteBytes(s ...[]byte) {
+	for _, b := range s {
+		_, _ = buf.Sys().Write(b)
+	}
+}
+
+// WriteStrings writes the given strings as UTF-8 to the buffer.
+func (buf *LazyBuffer) WriteStrings(strings ...string) {
+	for _, s := range strings {
+		_, _ = buf.Sys().WriteString(s)
+	}
+}

pkg/tools/tools.go

@@ -1,3 +1,2 @@
-//go:build tools
-
-package build
+// Package tools contains helpers
+package tools