From d01c914e7f2cd4333cadae13455ef013428f493c Mon Sep 17 00:00:00 2001
From: Lilleman auf Larv <lilleman@larvit.se>
Date: Tue, 29 Sep 2026 09:36:14 +0200
Subject: [PATCH] Assert prove, stepInto and columnItems panic on an unhandled
 node, and a bare table read is refused as a row

---
 render_test.go |  3 +++
 table_test.go  | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/render_test.go b/render_test.go
index 4aa67ae..8f0e5cd 100644
--- a/render_test.go
+++ b/render_test.go
@@ -61,10 +61,13 @@ func (*unhandledNode) isNode() {}
 
 func TestNodeSwitchesPanicOnAnUnhandledNode(t *testing.T) {
 	for name, call := range map[string]func(){
+		"columnItems": func() { columnItems(&unhandledNode{}) },
 		"contained":   func() { contained(&unhandledNode{}) },
 		"paths":       func() { paths(&unhandledNode{}) },
+		"prove":       func() { (&valueProof{}).prove(&unhandledNode{}) },
 		"render":      func() { render(nil, &unhandledNode{}, renderScope{}) },
 		"renderEdges": func() { renderEdges(&unhandledNode{}) },
+		"stepInto":    func() { _, _ = stepInto(&unhandledNode{}, "x") },
 	} {
 		mustPanic(t, name, call)
 	}
diff --git a/table_test.go b/table_test.go
index 98dadc3..8a3d656 100644
--- a/table_test.go
+++ b/table_test.go
@@ -1132,3 +1132,13 @@ func TestCellReadsMeetWhereTheRenderPairsTheRows(t *testing.T) {
 		t.Fatalf("New = %v, want 1280's shop and 1281's city kept apart, one draw of municipality rendering one of them", err)
 	}
 }
+
+func TestDatatypeRefusesARowRead(t *testing.T) {
+	for _, format := range []string{"{/region}", "{/region[01]}"} {
+		files := with(geo(), map[string]string{"row.json": `{"format":"","col":{"format":"` + format + `","datatype":"integer"}}`})
+		want := `"{name}" renders a row of region, which is composed text`
+		if _, err := New(WithoutShippedData(), WithDataPath(writeFiles(t, files))); err == nil || !strings.Contains(err.Error(), want) {
+			t.Errorf("%s: New = %v, want an error containing %q", format, err, want)
+		}
+	}
+}