gigaparsec/test/readerat.go

45 lines
867 B
Go

// Package test contains helpers for testing parsers.
package test
import (
"io"
"git.codemonkeysoftware.net/b/gigaparsec/cursor"
)
type errReaderAt struct {
err error
}
func (r errReaderAt) ReadAt([]byte, int64) (int, error) {
return 0, r.err
}
// ErrReaderAt returns an [io.ReaderAt] with a ReadAt method that always returns err.
func ErrReaderAt(err error) io.ReaderAt {
return errReaderAt{err: err}
}
type errCursor[T any] struct {
err error
pos uint64
}
func (c errCursor[T]) Read([]T) (uint64, cursor.Cursor[T], error) {
return 0, c, c.err
}
func (c errCursor[T]) At(pos uint64) cursor.Cursor[T] {
c.pos = pos
return c
}
func (c errCursor[T]) Pos() uint64 {
return c.pos
}
// ErrCursor return a [cursor.Cursor] with a Read method that always returns err.
func ErrCursor[T any](err error) cursor.Cursor[T] {
return errCursor[T]{err: err}
}