Convert selected dataTable rows to Integer in Cucumber

Question

sample.feature

Scenario Outline: My test case
Given: My data is loaded
When : My data is ready
Then: My data is
|name| value    |
|a   | <value1> |
|b   | <value2> |
|c   | <value3> |
|d   | <value4> |

Examples:
|value1| value2|value3| value4 |
|1     | 2     | 3    | text   |

steps.js //using node.js

Then('My data is', function (dataTable) {      
  console.log(dataTable);
// console output
   [['a', '1'],
    ['b', '2'],
    ['c', '3'],
    ['d', 'text']]

});

I need output as string value as string and Integer as Integer

// expected output
       [['a', 1],
        ['b', 2],
        ['c', 3],
        ['d', 'text']]

I don't want to hardcode based on name, because It may change. Is there a generic solution available?

Answer 1

You can detect if a value is numeric or not using isNaN(x). If the isNaN(x) function returns false, you can safely ignore that value in the cucumber data table. If the isNaN(x) function returns true then you can use the Number(x) function to convert the string to a number.

The isNaN and Number functions are complimentary. For any given input, if isNaN returns true, then passing that same input to Number will return a NaN value. If isNaN returns false then passing that input to Number will successfully convert it to a Number.

Remember that zero is a falsey value in JavaScript, so if (Number("0")) will be evaluate to false.

function parseDataTable(dataTable) {
  return dataTable.map((row, index) => {
    if (!isNaN(row[1])) {
      row[1] = Number(row[1]);
    }

    return row;
  });
}

And to use it in your step definition:

Then('My data is', function (dataTable) {      
  dataTable = parseDataTable(dataTable);

  console.log(dataTable);

  /*
    Should output:
    [
      ["a", 1],
      ["b", 2],
      ["c", 3],
      ["d", "text"]
    ]
  */
});