test(seahorse): add TestTriggerMigration for old-DB trigger upgrade path

Verifies that databases created with the old buggy FTS5 DELETE trigger
body are correctly migrated by runSchema: the old trigger causes DELETE
to fail, and after re-running runSchema (which drops and recreates the
triggers with the corrected body) DELETE works normally.

pkg/seahorse/schema_test.go

@@ -194,6 +194,84 @@ func TestMigrationSummaryParentsPK(t *testing.T) {
 	}
 }
 
+func TestTriggerMigration(t *testing.T) {
+	db := openTestDB(t)
+
+	// Run schema once to create tables and (correct) triggers
+	if err := runSchema(db); err != nil {
+		t.Fatalf("runSchema: %v", err)
+	}
+
+	// Drop correct triggers and recreate them with the old buggy body.
+	// The old trigger used INSERT INTO fts VALUES('delete', ...) which is wrong
+	// for non-external-content FTS5 tables.
+	oldSummariesDelete := `CREATE TRIGGER summaries_ad AFTER DELETE ON summaries BEGIN
+		INSERT INTO summaries_fts (summaries_fts, summary_id, content) VALUES('delete', old.summary_id, old.content);
+	END`
+	oldMessagesDelete := `CREATE TRIGGER messages_ad AFTER DELETE ON messages BEGIN
+		INSERT INTO messages_fts (messages_fts, message_id, content) VALUES('delete', old.message_id, old.content);
+	END`
+
+	for _, sql := range []string{
+		`DROP TRIGGER IF EXISTS summaries_ad`,
+		`DROP TRIGGER IF EXISTS messages_ad`,
+		oldSummariesDelete,
+		oldMessagesDelete,
+	} {
+		if _, err := db.Exec(sql); err != nil {
+			t.Fatalf("setup old trigger: %v", err)
+		}
+	}
+
+	// Insert a conversation and summary so we have something to delete
+	_, err := db.Exec(`INSERT INTO conversations (session_key) VALUES ('old-db-test')`)
+	if err != nil {
+		t.Fatalf("insert conversation: %v", err)
+	}
+	_, err = db.Exec(`INSERT INTO summaries (summary_id, conversation_id, kind, depth, content, token_count)
+		VALUES ('old-sum', 1, 'leaf', 0, 'old content', 5)`)
+	if err != nil {
+		t.Fatalf("insert summary: %v", err)
+	}
+
+	// The old trigger body is wrong for normal FTS5 — DELETE should fail.
+	_, err = db.Exec(`DELETE FROM summaries WHERE summary_id = 'old-sum'`)
+	if err == nil {
+		t.Error("expected error from old buggy trigger, but DELETE succeeded")
+	} else {
+		t.Logf("old trigger correctly causes error: %v", err)
+	}
+
+	// Now runSchema again — this drops and recreates the triggers with correct bodies.
+	err = runSchema(db)
+	if err != nil {
+		t.Fatalf("runSchema migration: %v", err)
+	}
+
+	// Insert again so we have data to delete
+	_, err = db.Exec(`INSERT INTO summaries (summary_id, conversation_id, kind, depth, content, token_count)
+		VALUES ('migrated-sum', 1, 'leaf', 0, 'new content', 5)`)
+	if err != nil {
+		t.Fatalf("insert after migration: %v", err)
+	}
+
+	// DELETE should now work with the corrected trigger body.
+	_, err = db.Exec(`DELETE FROM summaries WHERE summary_id = 'migrated-sum'`)
+	if err != nil {
+		t.Fatalf("DELETE after migration failed (trigger not corrected): %v", err)
+	}
+
+	// Verify the summary is gone
+	var count int
+	err = db.QueryRow(`SELECT count(*) FROM summaries WHERE summary_id = 'migrated-sum'`).Scan(&count)
+	if err != nil {
+		t.Fatalf("query after delete: %v", err)
+	}
+	if count != 0 {
+		t.Errorf("summary should be gone after DELETE, got count=%d", count)
+	}
+}
+
 func TestFTS5SQLConstants(t *testing.T) {
 	db := openTestDB(t)