How to implement criteria queries in unit test cases

Intrdouction to Plastic criteria

As the name suggest Plastic Criteria means somehow it is related to criteria.It is grails plugin to mock Grails Criteria for Unit Test cases.

Understand the need of Plastic Criteria : Why Plastic criteria plugin is required ?

1. Criteria queries and String-based queries like [executeQuery] are currently not supported in unit tests.

2. There's no support for HQL queries in unit tests yet.

3. Criteria queries and String-based queries aren't provided by mockDomain also. We have to mock your criteria queries itself like :

In case of Criteria :

mockFor(domianName).demand.static.createCriteria = { ->
    [list: { closure -> [  ] } ]
}

In case of ExceuteQuery : Suppose this one is the query we have to test through test cases

UserCompanyRoleMapping.executeQuery("select distinct user from UserCompanyRoleMapping u where u.company = :company and :admin in elements(u.roles)", [user: user, company: company, admin: companyAdminRole])

When we have to implement such type of string based query then do something like this :

List userList = [new User(params), new User(params)]
UserCompanyRoleMapping.metaClass.static.findAllUsersByCompanyAndRoles = { String company, def role -> userList }

and put in domain UserCompanyRoleMapping.groovy

static List findAllUsersByCompanyAndRoles(String company, def role) {
      executeQuery('from UserCompanyRoleMapping u where ...') // put your required query here 
   }

Conclusion of above :

As we can see in both the above approaches, the response of Criteria queries and String-based queries is not the actual one but it is defined earlier and hard coded(userList).

Solution :

To overcome such situations and to implement Criteria queries upto certain extent we require Plastic Criteria plugin.

Installation :

Put the following dependecy in your buildConfig :
plugins{
    test ":plastic-criteria:1.5.1"
}

How to use in test cases :

1. Import in the test case in which you want to mock criteria like

   import static plastic.criteria.PlasticCriteria.* 

2. Use the following syntax to mock required domains criteria in test case setup :

   mockCriteria([user,UserCompanyRoleMapping....])

Pros :

1. With the help of this plugin we are able to implement criteria(createCriteria and withCriteria) in our test cases.

2. It provide support for maximum nodes defined in criteria documentation.

3. Easy to use and understand.

Cons :

1. This plugin does not provide support for following :

>> count distinct

>> count

>> firstResult and some more.

For more detailed information visit the link : https://github.com/fabiooshiro/plastic-criteria

Thanks