Text columns with HeaderFilter will filter on null values as "null" string

Describe the bug I have table columns that are string/text types. When I enable filtering, any cell with a null value will filter as if the value of the cell was the string “null”. In testing, I also found that this occurs for “undefined” values as well.

Tabulator Info

• Which version of Tabulator are you using? v4.2.2

Working Example https://jsfiddle.net/haferje/gj0kampx/2/

To Reproduce Steps to reproduce the behavior:

1. Go to the JSFiddle URL that I linked
2. In the filter of column ‘Col 2’, type the values ‘null’ or ‘undefined’
3. See how the values are not treated as empty strings

Expected behavior Typing ‘null’ and ‘undefined’ in the filter should produce no matching rows

Desktop (please complete the following information):

• OS: Windows 10
• Browser: Google Chrome

Additional context The issue occurs at line 69 of the filter module in initializeColumn(). String(column.getFieldValue(data)) produces "null" and "undefined" for their respective value.

[haferje]

Sorry to hear that. I’ll be patient.

[haferje]

Code change looks good - I’ll try it when I get back to work Monday. Thank you!