fix: IndexNow hears of deleted and edited records

RecordDeleted marks the listed rows it excludes and RecordSaved the rows
whose lastmod it moves (indexnow_pending_at); the next rebuild sends
them to IndexNow as removed or changed and clears the marks. RecordSaved
checks for a nil event before reading it. TestIndexNow now deletes and
edits through the record events, as the admin does.

classes/lastmod_test.go

@@ -100,3 +100,14 @@ func testConfig(t *testing.T) *compass.Config {
 	}
 	return cfg
 }
+
+// TestRecordSavedNilEvent pins L2 IN-01: a nil event is ignored before it
+// is read.
+func TestRecordSavedNilEvent(t *testing.T) {
+	if err := RecordSaved(t.Context(), nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	if err := RecordDeleted(t.Context(), nil, nil); err != nil {
+		t.Fatal(err)
+	}
+}