fun SQLiteDatabase.doesTableExist(tableName: String): Boolean {
        val sql = "SELECT name FROM sqlite_master WHERE type='table';"
        val c = rawQuery(sql, null)
        while (c.moveToNext()) {
            if (c.getString(0) == tableName) return true
            else continue
        }

        return false
    }

    @Test fun columnsForCategoryTable() {
        val columns = getTableColumns(database.readableDatabase, "tbl_category")

        assertThat(columns).containsExactly("uuid", "name", "color")
    }

    @Test fun createDefaultCategoriesTable() {
        assertThat(database.readableDatabase.doesTableExist("tbl_category")).isTrue()
    }

    @Test fun createPolishCategoriesTable() {
        assertThat(database.readableDatabase.doesTableExist("tbl_category_pl")).isTrue()
    }

    @Test fun createGermanCategoriesTable() {
        assertThat(database.readableDatabase.doesTableExist("tbl_category_de")).isTrue()
    }