encoding.go

package validations

import (
	"encoding/base32"
	"encoding/base64"
	"encoding/json"
)

// Runtime helpers for the encoding validators. base32/base64 delegate to the
// stdlib decoders (authoritative — no regex, no bespoke padding rules); json uses
// encoding/json.Valid.
//
// The base32/base64 decoders allocate their decoded output even though we discard
// it, so those validators cost 1 small alloc on the success path. That is an
// accepted trade (M24): reimplementing the decoders by hand to save it would mean
// owning base64's residual-bit canonicality forever for a negligible gain — see
// the stdlib-parser note in CLAUDE.md. Do not hand-roll these to "fix" the alloc.

// ValidateBase64 reports whether s is valid standard (padded) base64.
func ValidateBase64(s string) error {
	if _, err := base64.StdEncoding.DecodeString(s); err != nil {
		return Base64Error{}
	}
	return nil
}

// ValidateBase64URL reports whether s is valid URL-safe (padded) base64.
func ValidateBase64URL(s string) error {
	if _, err := base64.URLEncoding.DecodeString(s); err != nil {
		return Base64URLError{}
	}
	return nil
}

// ValidateBase64RawURL reports whether s is valid URL-safe unpadded base64.
func ValidateBase64RawURL(s string) error {
	if _, err := base64.RawURLEncoding.DecodeString(s); err != nil {
		return Base64RawURLError{}
	}
	return nil
}

// ValidateBase32 reports whether s is valid standard (padded) base32.
func ValidateBase32(s string) error {
	if _, err := base32.StdEncoding.DecodeString(s); err != nil {
		return Base32Error{}
	}
	return nil
}

// ValidateJSON reports whether s is a well-formed JSON document.
func ValidateJSON(s string) error {
	if !json.Valid([]byte(s)) {
		return JSONError{}
	}
	return nil
}