Sorting with Undefined Values

[ldrummond]

Column sorting doesn't work as expected when column contains undefined values.

To Reproduce
Steps to reproduce the behavior:

1. Create a table
2. Add data as array of arrays, with sample values

[
 [undefined],
 [100],
 [300],
 [undefined],
 [50]
}

3. Test sorting of column; sorting does not occur. No errors are thrown.

** Device

• Chrome, Brave
• NPM Version 6.1.1

Additional context
May be able to fix by 1. Adding check for undefined in native sort function 2. Passing order (asc, desc) to comparator function for custom handling of undefined values. Unfortunately don't currently have time to check all possible causes and write PR, but may be able to in the next few weeks.

[JonasKellerer]

We seem to have a similar issue. When there are null values, then the sorting goes wrong. Some entries are sorted, but when the null value is reached, then the following values are no longer sorted. Writing an own sort function solves the issue.

[anguslee-wse]

This is my attempt of fixing the code in src/pipeline/sort/native.ts by using https://github.com/snovakovic/fast-sort.

import { inPlaceSort, ISortByObjectSorter } from 'fast-sort';

...

protected _process(data: Tabular): Tabular {
    const sortedRows = [...data.rows];
    /* sortedRows.sort(this.compareWrapper.bind(this)); */
    let sortBys: ISortByObjectSorter<Row>[] = [];
    for (const column of this.props.columns) {
      let sortBy: ISortByObjectSorter = {};
      if (column.direction === -1) {
        sortBy.desc = (r: Row): TCell => {
          return r.cells[column.index].data;
        };
      }
      else {
        sortBy.asc = (r: Row): TCell => {
          return r.cells[column.index].data;
        };
      }
      if (typeof column.compare === 'function') {
        sortBy.comparer = column.compare;
      }
      sortBys.push(sortBy);
    }
    inPlaceSort(sortedRows).by(sortBys);

    const sorted = new Tabular(sortedRows);
    // we have to set the tabular length manually
    // because of the server-side storage
    sorted.length = data.length;

    return sorted;
}