jupyterlab/packages/csvviewer/test/parse.spec.ts

// Copyright (c) Jupyter Development Team.
// Distributed under the terms of the Modified BSD License.

import { parseDSV as parser } from '../src';

describe('csvviewer/parse', () => {
  describe('parseDSV', () => {
    it('does basic parsing of csv files', () => {
      const data = `a,b,c,d\r\n0,1,2,3\r\n4,5,6,7`;
      const options = { data };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(0);
      expect(results.offsets).toEqual([0, 9, 18]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        9,
        11,
        13,
        15,
        18,
        20,
        22,
        24
      ]);
    });

    // For simplicity, we'll use \n as a row delimiter below.

    it('handles trailing row delimiter', () => {
      const data = `a,b,c,d\n0,1,2,3\n4,5,6,7\n`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 8, 16]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        8,
        10,
        12,
        14,
        16,
        18,
        20,
        22
      ]);
    });

    it('handles single-line data', () => {
      const data = `a,b,c,d\n`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([0, 2, 4, 6]);
    });

    it('handles changing the field delimiter', () => {
      const data = `a\tb\tc\td\n0\t1\t2\t3\n4\t5\t6\t7\n`;
      const options = { data, delimiter: '\t', rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 8, 16]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        8,
        10,
        12,
        14,
        16,
        18,
        20,
        22
      ]);
    });

    it('handles starting on a new row', () => {
      const data = `a,b,c,d\n0,1,2,3\n4,5,6,7\n`;
      const options = { data, rowDelimiter: '\n', startIndex: 8 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([8, 16]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([8, 10, 12, 14, 16, 18, 20, 22]);
    });

    it('handles a max row argument', () => {
      const data = `a,b,c,d\n0,1,2,3\n4,5,6,7\n`;
      const options = { data, rowDelimiter: '\n', maxRows: 2 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([0, 8]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([0, 2, 4, 6, 8, 10, 12, 14]);
    });

    it('handles a start index and max row argument', () => {
      const data = `a,b,c,d\n0,1,2,3\n4,5,6,7\n`;
      const options = { data, rowDelimiter: '\n', startIndex: 8, maxRows: 1 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([8]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([8, 10, 12, 14]);
    });

    it('adjusts columns to match first row by default', () => {
      const data = `a,b,c,d\n0,\n1,2,3,4,5,6`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 8, 11]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        8,
        10,
        10,
        10,
        11,
        13,
        15,
        17
      ]);
    });

    it('adjusts columns to match first row by default with CRLF row delimiter', () => {
      const data = `a,b,c,d\r\n0,\r\n1,2,3,4,5,6`;
      const options = { data, rowDelimiter: '\r\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 9, 13]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(4);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        9,
        11,
        11,
        11,
        13,
        15,
        17,
        19
      ]);
    });

    it('adjusts columns to match ncols', () => {
      const data = `a,b,c,d\n0,\n1,2,3,4,5,6`;
      const options = { data, rowDelimiter: '\n', ncols: 5 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 8, 11]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(5);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        7,
        8,
        10,
        10,
        10,
        10,
        11,
        13,
        15,
        17,
        19
      ]);
    });

    it('adjusts columns to match ncols with CRLF row delimiter', () => {
      const data = `a,b,c,d\r\n0,\r\n1,2,3,4,5,6`;
      const options = { data, rowDelimiter: '\r\n', ncols: 5 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 9, 13]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(5);
      expect(results.offsets).toEqual([
        0,
        2,
        4,
        6,
        7,
        9,
        11,
        11,
        11,
        11,
        13,
        15,
        17,
        19,
        21
      ]);
    });

    it('adjusts columns to match ncols with one row', () => {
      const data = `a,b,c,d`;
      const options = { data, rowDelimiter: '\n', ncols: 7 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(7);
      expect(results.offsets).toEqual([0, 2, 4, 6, 7, 7, 7]);
    });

    it('adjusts columns to match ncols with one row and trailing delimiter', () => {
      const data = `a,b,c,d\n`;
      const options = { data, rowDelimiter: '\n', ncols: 7 };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(7);
      expect(results.offsets).toEqual([0, 2, 4, 6, 7, 7, 7]);
    });

    it('handles a single row delimiter', () => {
      const data = `\n`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(1);
      expect(results.offsets).toEqual([0]);
    });

    it('handles adding columns or merging columns as necessary', () => {
      const data = `a,b,c\n,c,d,e,f\ng,h`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(3);
      expect(results.offsets).toEqual([0, 6, 15]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(3);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 4, 6, 7, 9, 15, 17, 18]);
    });
  });

  describe('parseDSV quotes', () => {
    it('does basic parsing of quoted csv files', () => {
      const data = `first,"last",address,city,zip`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(5);
      expect(results.offsets).toEqual([0, 6, 13, 21, 26]);
    });

    it('handles quotes with field delimiters', () => {
      const data = `a,"b,c",d\n"e","f"`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([0, 10]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 8, 10, 14, 17]);
    });

    it('handles quotes with row delimiters', () => {
      const data = `a,"b\nc",d\ne,f`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([0, 10]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 8, 10, 12, 13]);
    });

    it('handles quotes with escaped quotes', () => {
      const data = `a,"b""c",d\ne,f`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([0, 11]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 9, 11, 13, 14]);
    });

    it('handles setting the quote character', () => {
      const data = `a,'b'',\nc',d\ne,f`;
      const options = { data, rowDelimiter: '\n', quote: `'` };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(2);
      expect(results.offsets).toEqual([0, 13]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(2);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 11, 13, 15, 16]);
    });

    it('handles single quoted field', () => {
      const data = `"a"`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(1);
      expect(results.offsets).toEqual([0]);
    });

    it('handles empty quoted field', () => {
      const data = `a,"",b`;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(1);
      expect(results.offsets).toEqual([0]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(1);
      expect(results.ncols).toEqual(3);
      expect(results.offsets).toEqual([0, 2, 5]);
    });

    it('handles empty file', () => {
      const data = ``;
      const options = { data, rowDelimiter: '\n' };
      let results;

      results = parser({ ...options, columnOffsets: false });
      expect(results.nrows).toEqual(0);
      expect(results.offsets).toEqual([]);

      results = parser({ ...options, columnOffsets: true });
      expect(results.nrows).toEqual(0);
      expect(results.ncols).toEqual(0);
      expect(results.offsets).toEqual([]);
    });
  });
});

// Helpful debugging logging
// console.log(Array.from(results.offsets));
// console.log(Array.from(results.offsets).map((i, ind, arr) => data.slice(i, arr[ind + 1])));