Reject weight 0, a never-numeric calc operand and a repeat product past the cap; the CLI classifies ErrNoData

2026-09-02 18:23:03 +02:00
parent 34c933b2b3
commit 1b1b93b35f
8 changed files with 89 additions and 17 deletions
@@ -16,6 +16,7 @@ import (
 	crand "crypto/rand"
 	"embed"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"io/fs"
 	"math/rand/v2"
@@ -27,6 +28,9 @@ import (
 //go:embed data
 var shippedFS embed.FS

+// ErrNoData is returned by New when no source is loaded at all.
+var ErrNoData = errors.New("no data: WithoutShippedData needs at least one WithDataPath or WithDataFS")
+
 // Generator generates fake data from a loaded namespace tree. Create one with [New].
 // It is safe for concurrent use; a seeded sequence is reproducible only when drawn
 // from one goroutine.
@@ -99,7 +103,7 @@ func New(opts ...Option) (*Generator, error) {
 	}
 	sources = append(sources, c.sources...)
 	if len(sources) == 0 {
-		return nil, fmt.Errorf("fejkdata: no data: WithoutShippedData needs at least one WithDataPath or WithDataFS")
+		return nil, fmt.Errorf("fejkdata: %w", ErrNoData)
 	}
 	cats, err := loadData(sources)
 	if err != nil {