store/file: add WithDir option (#2038)

store/file/options.go

@@ -0,0 +1,16 @@
+package file
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/v3/store"
+)
+
+type dirKey struct{}
+
+// WithDir sets the directory to store the files in
+func WithDir(dir string) store.Option {
+	return func(o *store.Options) {
+		o.Context = context.WithValue(o.Context, dirKey{}, dir)
+	}
+}