test(phase-12): add discussion schema validation

backend/internal/web/handlers_discussion_test.go

@@ -65,6 +65,51 @@ func insertDiscussionTestMessage(t *testing.T, ctx context.Context, pool *pgxpoo
 	return msg
 }
 
+func TestDiscussionSchemaIncludesLifecycleMetadataAndBodyConstraints(t *testing.T) {
+	pool, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	q := sqlc.New(pool)
+	user := preInsertUser(t, ctx, q, "discussion-schema@example.com", "correct-horse-12")
+	tablo := insertDiscussionTestTablo(t, ctx, q, user, "Discussion Schema Tablo")
+
+	rows, err := pool.Query(ctx, `
+		SELECT column_name
+		FROM information_schema.columns
+		WHERE table_schema = current_schema()
+		  AND table_name = 'discussion_messages'
+	`)
+	if err != nil {
+		t.Fatalf("query discussion_messages columns: %v", err)
+	}
+	defer rows.Close()
+
+	columns := make(map[string]bool)
+	for rows.Next() {
+		var name string
+		if err := rows.Scan(&name); err != nil {
+			t.Fatalf("scan discussion_messages column: %v", err)
+		}
+		columns[name] = true
+	}
+	if err := rows.Err(); err != nil {
+		t.Fatalf("iterate discussion_messages columns: %v", err)
+	}
+	for _, want := range []string{"edited_at", "edited_by_user_id", "deleted_at", "deleted_by_user_id"} {
+		if !columns[want] {
+			t.Fatalf("discussion_messages missing lifecycle metadata column %q", want)
+		}
+	}
+
+	if _, err := pool.Exec(ctx, `INSERT INTO discussion_messages (tablo_id, author_user_id, body) VALUES ($1, $2, $3)`, tablo.ID, user.ID, "   "); err == nil {
+		t.Fatal("blank discussion message body inserted; want check constraint rejection")
+	}
+	if _, err := pool.Exec(ctx, `INSERT INTO discussion_messages (tablo_id, author_user_id, body) VALUES ($1, $2, $3)`, tablo.ID, user.ID, strings.Repeat("x", 10001)); err == nil {
+		t.Fatal("too-long discussion message body inserted; want check constraint rejection")
+	}
+}
+
 func TestDiscussionTabRendersHistoryAndComposer(t *testing.T) {
 	pool, cleanup := setupTestDB(t)
 	defer cleanup()