Prevent invalid user ID

[SumithThota]

PR Description:

Prevent Invalid User ID

This ServiceNow Business Rule prevents inserting or updating a record when:

• user_name is missing or invalid.
• Both first_name and last_name are missing or invalid.

Functionality Breakdown

1. isInvalid(value)

• Detects invalid values in user fields.
• Returns true if:
  • Value is null, undefined, or empty ("")
  • Value (after trimming spaces and lowering case) equals "null"

Example:

isInvalid(null);        // true
isInvalid("");          // true
isInvalid("NULL");      // true
isInvalid("john");      // false

2. current.setAbortAction(true)

• Stops the record from being inserted or updated.
• Used inside Before Business Rules.
• Prevents saving invalid data to the database.

3. gs.addErrorMessage("...")

• Displays a user-friendly error message at the top of the form.
• Helps users understand why the save was blocked.

Notes

• Case-insensitive — handles "null", "NULL", "Null", etc.
• Works best in Before Business Rules to stop invalid data before saving.
• Adding gs.addErrorMessage() helps users understand the validation reason.

Pull Request Checklist

Overview

• Put an x inside of the square brackets to check each item.
• I have read and understood the CONTRIBUTING.md guidelines
• My pull request has a descriptive title that accurately reflects the changes and the description has been filled in above.
• I've included only files relevant to the changes described in the PR title and description
• I've created a new branch in my forked repository for this contribution

Code Quality

• My code is relevant to ServiceNow developers
• My code snippets expand meaningfully on official ServiceNow documentation (if applicable)
• I've disclosed use of ES2021 features (if applicable)
• I've tested my code snippets in a ServiceNow environment (where possible)

Repository Structure Compliance

• I've placed my code snippet(s) in one of the required top-level categories:
  • Core ServiceNow APIs/
  • Server-Side Components/
  • Client-Side Components/
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• I've used appropriate sub-categories within the top-level categories
• Each code snippet has its own folder with a descriptive name

Documentation

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• The README.md includes:
  • Description of the code snippet functionality
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Restrictions

• My PR does not include XML exports of ServiceNow records
• My PR does not contain sensitive information (passwords, API keys, tokens)
• My PR does not include changes that fall outside the described scope

[github-actions]

👋 Unassigning @Atul-LNG due to inactivity (> 60 min without comments/reviews). This PR remains open for other reviewers.

[Atul-LNG]

Thanks for the contribution @SumithThota