Duplicate email addresses are allowed

[nus-se-script]

Steps to reproduce:

1. use the commands addPerson n=A p=98765432 e=johnd@example.com a=John street, block 123,#01-01 addPerson n=A1 p=98765432 e=johnd@example.com a=John street, block 123,#01-01

Allowing for 2 people to possess the same email address, would this be realistic in a practical sense?

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_{[original: nus-cs2103-AY2324S1/pe-interim#2587] [original labels: severity.Low type.FunctionalityBug]}

[wui-hong]

Team's Response

Thank you for your bug report. This is a duplicate of another issue, but the same response applies.

In our application, we have decided that names are unique to identify people with respect to the needs of our target audience. However, allowing Telegram Handles, phone numbers and email addresses to be duplicated is an intentional choice of our application. This applies for both the addPerson and editPerson commands. 
Making addresses not unique was more straightforward as multiple people can live in the same place. However, for the other fields, there was more to consider. In some cases, it is possible that a contact does not want to disclose their direct personal details (phone number / email / Telegram). They may instead disclose a more general phone contact. Some examples where multiple people may share the same contact details include:

• Any contacts who might share landline numbers instead of their personal numbers. Multiple people can share the same landline. For instance, suitemates might use a landline number.
• Residential Fellows, Staff, Hall Leaders might share the Hall / Dorm’s contact information for privacy / formal means settling dorm-related expenses. For instance, it would be important for them to go through the dorm’s management office to get proper reimbursement. This leads to multiple people sharing a single office’s contact (email / phone number / Telegram).
• Staff might use a common, share email for communication.
• People from clubs, societies, and organisations might use a common Telegram Handle, phone number, email as a single point of contact.
• Contacts might have broken phones / no SIM, and may need to share their contacts with another person (phone number / Telegram) temporarily.


We aim to be flexible with our application, only restricting uniqueness in names as it is necessary, whereas giving the freedom for users to have duplicates in other fields. Overly enforcing the uniqueness of fields can be seen as overzealous validation that may inconvenience our target audience who may encounter contacts with common details. This design decision aligns with real examples that accommodates to the diverse user needs, and follows common standards in leading contact management applications such as Apple Contacts where flexibility in contact details is allowed.


Duplicate status (if any):

Duplicate of #4239