data-invalid event not working with from stream

[keatz55]

I have the following snippet almost taken verbatim from the parse tests w/ in lib:
https://github.com/C2FO/fast-csv/blob/5cf10be9bc9dbc87abfce04ccf2a03dd5d1f8a9e/test/parsing.test.js

csv
    .fromStream(request(job.data.file), { headers: true })
    .validate(function (data, next) {  
      next(new Error("Validation ERROR!!!!"));
    })
    .on("data", function (data, index) {
      console.log('DATA: ', data, index);
    })
    .on("data-invalid", function (data, index) {
      console.log('DATA_INVALID: ', data, index);
    })
    .on("error", function (err) {
      console.log('ERROR: ', err);
    })
    .on("end", function (count) {
      console.log('END: ', count);
    });

Whenever I run this code, "data-invalid" is completely bypassed and only "error" is hit.

I also looked at the code and saw that a next(null, false) can trigger the "data-invalid" emit event. However, every index is listed as 0.

[doug-martin]

In your example that is expected behavior, the next callback should mainly be used for async validation and an error should only be passed to the callback if an error occurs that should stop the stream processing.

Here is a slightly modified example that shows each data and data-invalid event being hit, with a final error on the last row.

const CSV_CONTENT = [
    'id,name,location',
    '1,Joe,Boston',
    '2,Emily,San Francisco',
    ',Harold,Dallas',
    ',Kate,Seattle',
    '5,William,New York',
].join('\n');

let count = 0;
csv
    .fromString(CSV_CONTENT, { headers: true })
    .validate((data, next) => {
        count += 1;
        if (count === 5) {
            return next(new Error('Validation ERROR!!!!'));
        }
        return next(null, count % 2 === 0);
    })
    .on('data', data => console.log('DATA: ', data))
    .on('data-invalid', (data, index) => console.log('DATA_INVALID: ', data, index))
    .on('error', err => console.log('ERROR: ', err))
    .on('end', rowCount => console.log('END: ', rowCount));

Output:

DATA_INVALID:  { id: '1', name: 'Joe', location: 'Boston' } 1
DATA:  { id: '2', name: 'Emily', location: 'San Francisco' }
DATA_INVALID:  { id: '', name: 'Harold', location: 'Dallas' } 2
DATA:  { id: '', name: 'Kate', location: 'Seattle' }
ERROR:  Error: Validation ERROR!!!!

In that example there is an error where the row count is not properly incremented and is covered under #130