```ruby
require 'test_helper'
require 'user'

class StudentsApiTest < ActiveSupport::TestCase
  include Rack::Test::Methods
  include TestHelpers::AuthHelper
  include TestHelpers::JsonHelper

  def app
    Rails.application
  end

  def test_get_students_with_authentication
    # Build admin user
    adminUser = FactoryGirl.build(:user, :admin)

    # The get that we will be testing.
    get with_auth_token '/api/students/?unit_id=1',adminUser
    response = last_response_body

    assert_equal 200, last_response.status
  end

  def test_get_students_without_authentication
    # Build student user
    studentUser = FactoryGirl.build(:user, :student)

    # The get that we will be testing.
    get with_auth_token '/api/students/?unit_id=1', studentUser
    assert_equal 403, last_response.status
  end

  def test_get_students_without_parameters
    # Build admin user
    adminUser = FactoryGirl.build(:user, :admin)


    # The get that we will be testing.
    get with_auth_token '/api/students/',adminUser
    assert_equal 400, last_response.status
  end
end
```

Change get tests for students_api
user
```ruby
require 'test_helper'
require 'user'

class StudentsApiTest < ActiveSupport::TestCase
  include Rack::Test::Methods
  include TestHelpers::AuthHelper
  include TestHelpers::JsonHelper

  def app
    Rails.application
  end

  def test_get_students_with_authentication

    # Create unit
    newUnit = FactoryGirl.create(:unit)

    #Create campus
    newCampus = FactoryGirl.create(:campus)

    # Create student
    studentUser = FactoryGirl.create(:user, :student)

    # Assign student to the unit
    newUnit.enrol_student(studentUser, newCampus)

    # The get that we will be testing.
    get with_auth_token "/api/students/?unit_id=#{newUnit.id}"
    response_received = last_response_body

    # check return value
    assert_equal response_received[0]['first_name'],studentUser.first_name
    assert_equal 200, last_response.status
  end

  def test_get_students_without_authentication
    # Create student user
    studentUser = FactoryGirl.create(:user, :student)

    # Create unit
    newUnit = FactoryGirl.create(:unit)

    #Create campus
    newCampus = FactoryGirl.create(:campus)

    # Assign student to the unit
    newUnit.enrol_student(studentUser, newCampus)

    # The get that we will be testing.
    get with_auth_token "/api/students/?unit_id=#{newUnit.id}", studentUser
    assert_equal 403, last_response.status
  end

  def test_get_students_without_parameters

    # The get that we will be testing without parameters.
    get with_auth_token '/api/students/'
    assert_equal 400, last_response.status
  end
end
```
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