PASS: datagrid JS binding is [object HTMLDataGridElement] PASS: Initial value of datagrid.columns is defined. PASS: datagrid.columns JS binding is [object DataGridColumnList] PASS: Initial length of datagrid.columns is 2. PASS: newCol JS binding is [object HTMLDataGridColElement] PASS: We have three columns in the list. PASS: The column's ID is from as expected. PASS: The column's label is From as expected. PASS: The column's type is text as expected. PASS: The column's primary property is true as expected. PASS: The column's sortable property is 2 as expected. PASS: The first column is the primary column. PASS: After removing a column, the length of datagrid.columns is 2. PASS: No column is the primary column.