How to use folder_format?

[jpratt2]

Can I have an example of the use of "folder_format" that is listed here?
https://nightwatchjs.org/guide/configuration/customising-test-output.html
How can it be used to retain reports over test runs?

From documentation: "Used as a prefix for HTML report folder. This can be utilised to retain HTML report across test runs"

[jpratt2]

It may be related to nightwatchjs/nightwatch#3309 for "retain_report".

[garg3133]

@jpratt2 If you set the folder_format, it would be used as a parent folder name inside which the HTML report for the current test run will be saved.

For ex., if you set folder_format to say "html_reports", then your HTML report will be saved inside test_output/html_reports/nightwatch-html-report/. But since your folder_format would be the same for each test run, it would just overwrite the previous test HTML report.

So, to retain your HTML reports, the idea here is to use different values in folder_format for each test run. This can be done by setting the folder_format to a function, like below:

folder_format: function() {
  return `html-report-${Date.now().toString()}`;
},

Doing so would create a new folder inside test_output every time you run a test containing the HTML report for that test run.