Better handling of validation errors when remote facility does not require passwords

[jredrejo]

Summary

When importing users in a LOD device, authentication errors were not passed as ValidationErrors to the frontend. Also, when the remote facility allowed authentication without password, if the username didn't exist no known error was being passed to the frontend.
This PR fixes these problems.

References

Closes: #11605

Reviewer guidance

Steps to test this PR are described in the steps to reproduce #11605

Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b10.dev0_git.85.gc34d07d3.pex
Windows Installer (EXE)	kolibri-0.16.0b10.dev0+git.85.gc34d07d3-unsigned.exe
Debian Package	kolibri_0.16.0b10.dev0+git.85.gc34d07d3-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b10.dev0+git.85.gc34d07d3-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b10.dev0+git.85.gc34d07d3-0.1.0-debug.apk
TAR file	kolibri-0.16.0b10.dev0+git.85.gc34d07d3.tar.gz
WHL file	kolibri-0.16.0b10.dev0+git.85.gc34d07d3-py2.py3-none-any.whl

[rtibbles]

These changes make sense to me codewise, and do as described in the PR description. Needs manual QA to verify.

[pcenov]

Hi @jredrejo, I confirm that now the message "Incorrect username or password" is being displayed for not existing learner accounts or mistyped username/password.

Here's a list with other issues that I am aware of in terms of validation. Perhaps some of those are in scope for this PR, the rest can be fixed separately:

• there's still no error message displayed if the user attempts to submit an empty form (that's valid both for the learner credentials form and for the admin credentials form)
• when we have only the 'Username' field being displayed and I enter an admin username then I am still seeing the "Incorrect username or password" - I think in that case we should be showing the Device limitations modal
• if after seeing the "Incorrect username or password" message I click the Use an admin account link then the "Incorrect username or password" message is still displayed above the empty form for the admin credentials
• no distinction for capitals vs small letters in the username - I think this should be fixed as part of fix: validation #11672
• when we have both the Username and Password fields displayed and I enter the username of a learner who was originally created without a password then it's not accepted as valid credentials and I have to import that learner signed in as an admin. This is probably OK, but just mentioning it here as an edge case in case that could be considered.

[jredrejo]

Hi @jredrejo, I confirm that now the message "Incorrect username or password" is being displayed for not existing learner accounts or mistyped username/password.

Here's a list with other issues that I am aware of in terms of validation. Perhaps some of those are in scope for this PR, the rest can be fixed separately:

• there's still no error message displayed if the user attempts to submit an empty form (that's valid both for the learner credentials form and for the admin credentials form)
• when we have only the 'Username' field being displayed and I enter an admin username then I am still seeing the "Incorrect username or password" - I think in that case we should be showing the Device limitations modal
• if after seeing the "Incorrect username or password" message I click the Use an admin account link then the "Incorrect username or password" message is still displayed above the empty form for the admin credentials
• no distinction for capitals vs small letters in the username - I think this should be fixed as part of fix: validation #11672
• when we have both the Username and Password fields displayed and I enter the username of a learner who was originally created without a password then it's not accepted as valid credentials and I have to import that learner signed in as an admin. This is probably OK, but just mentioning it here as an edge case in case that could be considered.

hi @pcenov are there open issues for these items? I was not aware of any of these excepting #11540 and want to avoid conflicts with other people work. In case there are not other open issues, please edit #11605 to add this list or create a new one so we can focus and schedule the work because your list is quite overwhelming and means there are quite a lot of problems that can look similar to #11605 but are technically different as most of them are in the frontend not (or not only) in the backend validation.

[pcenov]

Ok, thanks @jredrejo - I have created a follow-up issue as suggested.