adding feature of user search

[AlexMiao7]

Description

Adding three functions for user search by id/name/username using mongoose.

Related Issue

Solves #20

Type of change

• [x] New feature (enhancement)

How Has This Been Tested?

This schema has not been tested.

Checklist:

• [x] Does a similar (open or closed) pull request not already exist?
• [x] Is the pull request head repository a fork repository?
• [x] Is the pull request compare branch a development branch?
• [x] Is the code documented, particularly in hard-to-understand areas?
• [x] Does the code build without new warnings?
• [x] Has testing been performed that proves changes are effective and work?
• [x] Has a self- and/or peer-review of the code been performed?
• [x] Have dependent changes been merged and published in downstream modules?
• [x] Does all new and existing automated testing pass?
• [x] Is the person responsible for the repository assigned to the pull request?
• [x] Is the pull request linked to a project?
• [x] Is the pull request linked to a milestone?

For more information, refer to the Contributing Guidelines document.

[R055A]

I will help fix this soon

[AlexMiao7]

I have left some suggestions.

It is not a good idea to rely on data being manually entered in the database for the tests to pass.

what i was thinking is that I manually inserted some data into the databbase and try if i can search those data by id, and I also try to search some data which does not exist. So what else could I do in order to test the function?

[R055A]

I have left some suggestions. It is not a good idea to rely on data being manually entered in the database for the tests to pass.

what i was thinking is that I manually inserted some data into the databbase and try if i can search those data by id, and I also try to search some data which does not exist. So what else could I do in order to test the function?

The problem with that is new changes have all collection data in the test database wiped before each test and only the test database is used for tests.