037dc53030
- lagoon.OrderBy takes variadic lagoon.OrderOption values; lagoon.Collate(name) emits a validated, double-quoted COLLATE clause (e.g. "pl-x-icu") - remove the exported CheckLocale and the ICU pl-PL check from Open and Use - framework test containers and per-test databases are plain PostgreSQL - lagoon README, root README and docs pages drop the locale requirement; queries-and-pagination gains a "Sorting with a collation" section backed by ExampleCollate
114 lines
3.2 KiB
Go
114 lines
3.2 KiB
Go
package lagoon
|
|
|
|
import (
|
|
"fmt"
|
|
"strings"
|
|
|
|
"gorm.io/gorm"
|
|
)
|
|
|
|
// maxCollationName is PostgreSQL's identifier limit (NAMEDATALEN-1).
|
|
const maxCollationName = 63
|
|
|
|
// OrderOption changes how OrderBy builds its ORDER BY clause.
|
|
type OrderOption func(*orderOptions)
|
|
|
|
type orderOptions struct {
|
|
collation string
|
|
hasCollation bool
|
|
}
|
|
|
|
// Collate sorts the column with the named PostgreSQL collation, for example
|
|
// the ICU collation pl-x-icu for Polish alphabetical order. ICU collations
|
|
// exist in any ICU-enabled PostgreSQL server, so they need no database
|
|
// setup. The name is validated and emitted as a double-quoted identifier;
|
|
// an invalid name makes OrderBy return an error.
|
|
func Collate(name string) OrderOption {
|
|
return func(o *orderOptions) {
|
|
o.collation = name
|
|
o.hasCollation = true
|
|
}
|
|
}
|
|
|
|
// OrderBy appends an ORDER BY for an allow-listed qualified column.
|
|
// Identifiers and directions are never taken from untrusted input: column
|
|
// must match allowed exactly, and dir must be asc or desc. No COLLATE is
|
|
// emitted unless Collate is passed; without it, text sorts by the
|
|
// database's default collation.
|
|
func OrderBy(db *gorm.DB, column, dir string, allowed []string, opts ...OrderOption) (*gorm.DB, error) {
|
|
if db == nil {
|
|
return nil, fmt.Errorf("lagoon: gorm db is nil")
|
|
}
|
|
clause, err := orderClause(column, dir, allowed, resolveOrderOptions(opts))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return db.Order(clause), nil
|
|
}
|
|
|
|
func resolveOrderOptions(opts []OrderOption) orderOptions {
|
|
var o orderOptions
|
|
for _, opt := range opts {
|
|
if opt != nil {
|
|
opt(&o)
|
|
}
|
|
}
|
|
return o
|
|
}
|
|
|
|
func orderClause(column, dir string, allowed []string, opts orderOptions) (string, error) {
|
|
if !allowListed(column, allowed) {
|
|
return "", fmt.Errorf("lagoon: order column %q is not allow-listed", column)
|
|
}
|
|
var direction string
|
|
switch strings.ToLower(strings.TrimSpace(dir)) {
|
|
case "asc":
|
|
direction = "ASC"
|
|
case "desc":
|
|
direction = "DESC"
|
|
default:
|
|
return "", fmt.Errorf("lagoon: order direction %q is not allow-listed", dir)
|
|
}
|
|
if !opts.hasCollation {
|
|
return column + " " + direction, nil
|
|
}
|
|
if !validCollationName(opts.collation) {
|
|
return "", fmt.Errorf("lagoon: order collation %q is not a valid collation name", opts.collation)
|
|
}
|
|
return column + " COLLATE " + quoteCollation(opts.collation) + " " + direction, nil
|
|
}
|
|
|
|
// validCollationName accepts 1-63 ASCII bytes: letters, digits and
|
|
// underscore first, then letters, digits, '_', '-', '.' and '@'. The set
|
|
// excludes the double quote, so a valid name cannot leave its identifier.
|
|
func validCollationName(name string) bool {
|
|
if len(name) == 0 || len(name) > maxCollationName {
|
|
return false
|
|
}
|
|
for i := 0; i < len(name); i++ {
|
|
c := name[i]
|
|
switch {
|
|
case c >= 'a' && c <= 'z', c >= 'A' && c <= 'Z', c >= '0' && c <= '9', c == '_':
|
|
case i > 0 && (c == '-' || c == '.' || c == '@'):
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
// quoteCollation wraps a validated collation name as a PostgreSQL quoted
|
|
// identifier.
|
|
func quoteCollation(name string) string {
|
|
return `"` + strings.ReplaceAll(name, `"`, `""`) + `"`
|
|
}
|
|
|
|
func allowListed(column string, allowed []string) bool {
|
|
for _, a := range allowed {
|
|
if a == column {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|