From 526b4c84fd87b93627690ae8f8bf6669d9e1cc29 Mon Sep 17 00:00:00 2001
From: Lilleman auf Larv <lilleman@larvit.se>
Date: Tue, 29 Sep 2026 03:51:03 +0200
Subject: [PATCH] Test that disagreements holds every key disagreement builds,
 and a miss panics as an internal error

---
 datatype_test.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/datatype_test.go b/datatype_test.go
index 9ba95aa..b08aac0 100644
--- a/datatype_test.go
+++ b/datatype_test.go
@@ -220,3 +220,20 @@ func TestNullColumn(t *testing.T) {
 		t.Errorf("List() = %v, want the null column row.gone, which Fake accepts", f.List())
 	}
 }
+
+func TestDisagreementsHoldEveryKeyDisagreementBuilds(t *testing.T) {
+	kinds := []itemKind{kindText, kindReads, kindDeclares}
+	for _, fix := range kinds {
+		for _, other := range kinds[fix:] {
+			if other == kindText {
+				continue
+			}
+			for _, proven := range []bool{false, true} {
+				if disagreementFix(disagreementKey{fix, other, proven}) == nil {
+					t.Errorf("disagreementFix(%v, %v, %v) = nil", fix, other, proven)
+				}
+			}
+		}
+	}
+	mustPanic(t, "two text items", func() { disagreementFix(disagreementKey{kindText, kindText, false}) })
+}