1 files changed, 28 insertions, 0 deletions
diff --git a/internal/plan/index_test.go b/internal/plan/index_test.go
new file mode 100644
index 0000000..b157f56
--- /dev/null
+++ b/internal/plan/index_test.go
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package plan
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestMaxIndex(t *testing.T) {
+	for in, want := range map[string]int{
+		"Work/Acme":          0,
+		"{name}":             0,
+		"{1}":                1,
+		"Work/{2}/{1}":       2,
+		"{stem}-{9}{ext}":    9,
+		"{{1}}":              0,
+		"{mtime:%Y}/{3}-{1}": 3,
+	} {
+		got, err := MaxIndex(in)
+		if err != nil || got != want {
+			t.Errorf("MaxIndex(%q) = %d, %v; want %d", in, got, err, want)
+		}
+	}
+	if _, err := MaxIndex("{name"); err == nil || !strings.Contains(err.Error(), "unclosed placeholder") {
+		t.Errorf("unclosed: %v", err)
+	}
+}