parse csv with javascript

parsce-csv-test.js

import parseCsv from 'zipbooks/utils/parse-csv'
import { module, test } from 'qunit'

module('Unit | Utility | parse-csv', function(_hooks) {

  test('parses csv successfully', function(assert) {
    let result = parseCsv('name,age\nadam,31\ntim,32\n"St, clair",26')
    assert.equal(JSON.stringify(result), '[["name","age"],["adam","31"],["tim","32"],["St, clair","26"]]')
  })

  test('parses with header', function(assert) {
    let result = parseCsv('name,age\nadam,31\ntim,32\n"St, clair",26', {headers: true})
    assert.equal(JSON.stringify(result), '[{"name":"adam","age":"31"},{"name":"tim","age":"32"},{"name":"St, clair","age":"26"}]')
  })

})

parse-csv.js

// extracted from: https://stackoverflow.com/a/14991797/798055

export default function parseCsv(str, opts = {}) {
  var arr = [];
  var quote = false;  // true means we're inside a quoted field
  var col, c;

  // iterate over each character, keep track of current row and column (of the returned array)
  for (var row = col = c = 0; c < str.length; c++) {
    var cc = str[c], nc = str[c+1];        // current character, next character
    arr[row] = arr[row] || [];             // create a new row if necessary
    arr[row][col] = arr[row][col] || '';   // create a new column (start with empty string) if necessary

    // If the current character is a quotation mark, and we're inside a
    // quoted field, and the next character is also a quotation mark,
    // add a quotation mark to the current column and skip the next character
    if (cc == '"' && quote && nc == '"') { arr[row][col] += cc; ++c; continue; }

    // If it's just one quotation mark, begin/end quoted field
    if (cc == '"') { quote = !quote; continue; }

    // If it's a comma and we're not in a quoted field, move on to the next column
    if (cc == ',' && !quote) { ++col; continue; }

    // If it's a newline (CRLF) and we're not in a quoted field, skip the next character
    // and move on to the next row and move to column 0 of that new row
    if (cc == '\r' && nc == '\n' && !quote) { ++row; col = 0; ++c; continue; }

    // If it's a newline (LF or CR) and we're not in a quoted field,
    // move on to the next row and move to column 0 of that new row
    if (cc == '\n' && !quote) { ++row; col = 0; continue; }
    if (cc == '\r' && !quote) { ++row; col = 0; continue; }

    // Otherwise, append the current character to the current column
    arr[row][col] += cc;
  }

  if (opts.headers) {
    let header = arr[0]
    let rest = arr.slice(1)
    return rest.map(r => {
      return r.reduce((acc, v, i) => {
        let key = header[i]
        acc[key] = v
        return acc
      }, {})
    })
  }
  else {
    return arr;
  }
}