On Editing Phone Number of a user , No check for already existing duplicate phone numbers

[devivy]

Before the command:

After the command:

On editing the phone number of user 2 , the command proceeds to edit the phone number despite the 1st user having the same number.
As an Owner, it will be inconvenient for me to contact my user if they have entered an incorrect phone number by mistake.

There should be a number verifying system for duplicates.

[nus-se-script]

Team's Response

No details provided by team.

The 'Original' Bug

[The team marked this bug as a duplicate of the following bug]

Feature Flaw: Duplicate Phone Numbers not handled.

2 users cannot have the same phone number. However, When I add in 2 users with the same phone number, No error message was given.

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_{[original: nus-cs2103-AY2425S1/pe-interim#3192] [original labels: severity.Medium type.FeatureFlaw]}

Their Response to the 'Original' Bug

[This is the team's response to the above 'original' bug]

Hi tester, this was intentional, as there can be multiple contacts that are reached via the same phone number, e.g. a company customer service hotline or if you are a private tutor who teaches siblings, then the phone number would be the same parent if each contact represents a student. Some buildings can also have the same landline / hotline number, but different extensions, which may not be disclosed to the user.

Thank you.

Items for the Tester to Verify

❓ Issue duplicate status

Team chose to mark this issue as a duplicate of another issue (as explained in the Team's response above)

• I disagree

Reason for disagreement: [replace this with your explanation]

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❓ Issue response

Team chose [response.Rejected]

• I disagree

Reason for disagreement: Dear Dev Team,

I respectfully but strongly disagree with accepting duplicate phone numbers as intentional behaviour. Here's why:

• Edge Cases vs. Data Integrity:
  -Your examples (company hotlines, siblings, building numbers) are edge cases.
  -Designing core validation around edge cases creates larger risks.
  -These scenarios should be handled through proper data modelling, not by compromising basic validation.

• Current Implementation Risks:
  -No way to distinguish between legitimate shared numbers and data entry errors.
  -No warning/confirmation when entering duplicate numbers.
  -No visual indication that a number is shared across contacts.
  -No way to bulk-update shared numbers if the main number changes.

• Industry Standard Practice:
  -Major contact management systems (Salesforce, HubSpot) don't allow duplicate numbers by default
  -They handle shared numbers through proper data structures
  -This is because phone validation is a fundamental data integrity requirement

Thank you.

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❓ Issue severity

Team chose [severity.Low]
Originally [severity.Medium]

• I disagree

Reason for disagreement: [replace this with your explanation]

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