Groovy 2.2.1

groovy.mock.interceptor
[Groovy] Class MockFor

java.lang.Object
  groovy.mock.interceptor.MockFor

class MockFor

MockFor supports (typically unit) testing of classes in isolation by allowing a strictly ordered expectation of the behavior of collaborators to be defined. A typical test scenario involves a class under test (CUT) and one or more collaborators. In such a scenario it is often desirable to just test the business logic of the CUT. One strategy for doing that is to replace the collaborator instances with simplified mock objects to help isolate out the logic in the CUT. MockFor allows such mocks to be created using meta-programming. The desired behavior of collaborators is defined as a behavior specification. The behavior is enforced and checked automatically. With MockFor, a mock's expectation is always sequence dependent and its use automatically ends with a verify(). Typical usage is as follows:

 import groovy.mock.interceptor.MockFor

 class Person {
   String first, last
 }

 class Family {
   Person father, mother
   def nameOfMother() { "$mother.first $mother.last" }
 }

 def mock = new MockFor(Person)
 mock.demand.getFirst{ 'dummy' }
 mock.demand.getLast{ 'name' }
 mock.use {
   def mary = new Person(first:'Mary', last:'Smith')
   def f = new Family(mother:mary)
   assert f.nameOfMother() == 'dummy name'
 }
 
Here, Family is our class under test and Person is the collaborator. We are using normal Groovy property semantics here; hence the statement mother.last causes a call to mother.getLast() to occur. The following features are supported: See also: StubFor.
Authors:
Dierk Koenig
Paul King


Property Summary
Class clazz

Demand demand

def expect

Ignore ignore

Map instanceExpectations

MockProxyMetaClass proxy

 
Constructor Summary
MockFor(Class clazz, boolean interceptConstruction = false)

The optional interceptConstruction flag allows mocking of constructor calls.

 
Method Summary
static GroovyObject getInstance(Class clazz, def args)

def ignore(Object filter, Closure filterBehavior = null)

Allows particular method calls to be ignored and not treated as part of the required behavior specification.

GroovyObject makeProxyInstance(def args, boolean isDelegate)

GroovyObject proxyDelegateInstance(def args = null)

Allows a more traditional instance-style mocking paradigm.

GroovyObject proxyInstance(def args = null)

Allows a more traditional instance-style mocking paradigm.

void use(Closure closure)

Identifies the Closure where the mocked collaborator behavior will be applied and verified.

void use(GroovyObject obj, Closure closure)

void verify(GroovyObject obj)

If manual verification is required

 
Methods inherited from class Object
wait, wait, wait, equals, toString, hashCode, getClass, notify, notifyAll
 

Property Detail

clazz

Class clazz


demand

Demand demand


expect

def expect


ignore

Ignore ignore


instanceExpectations

Map instanceExpectations


proxy

MockProxyMetaClass proxy


 
Constructor Detail

MockFor

MockFor(Class clazz, boolean interceptConstruction = false)
The optional interceptConstruction flag allows mocking of constructor calls. These are represented in the demand specification using the class name as this example shows:
 import groovy.mock.interceptor.MockFor
 class Person {
   String first, last
 }
 def interceptConstructorCalls = true
 def mock = new MockFor(Person, interceptConstructorCalls)
 def dummy = new Person(first:'Tom', last:'Jones')
 mock.demand.with {
   Person() { dummy } // expect constructor call, return dummy
   getFirst() {'John'}
   getLast() {'Doe'}
 }
 mock.use {
   def p = new Person(first:'Mary', last:'Smith')
   assert p.first == 'John'
   assert p.last == 'Doe'
 }
 


 
Method Detail

getInstance

static GroovyObject getInstance(Class clazz, def args)


ignore

def ignore(Object filter, Closure filterBehavior = null)
Allows particular method calls to be ignored and not treated as part of the required behavior specification. If you don't specify a return closure the method call will fall through to the underlying instance, i.e. half-mock style. The filter object is invoked using the normal Groovy isCase() semantics. Here are some examples:
 import groovy.mock.interceptor.MockFor
 class Person {
   String first, last
   def name() { "$first $last" }
   def ignoreMe() { 'baz' }
   def ignoreMeToo() { ignoreMe() }
   def ignoreMeThree() { ignoreMe() }
 }
 def mock = new MockFor(Person)
 mock.ignore(~'get.*')
 mock.ignore('ignoreMeToo') { 'boo' }
 mock.ignore(~'ignoreMe.*')
 mock.demand.name{ 'John' }
 mock.use {
   def p = new Person(first:'Mary', last:'Smith')
   assert p.first == 'Mary'
   assert p.last == 'Smith'
   assert p.name() == 'John'
   assert p.ignoreMe() == 'baz'
   assert p.ignoreMeToo() == 'boo'
   assert p.ignoreMeThree() == 'baz'
 }
 
There is also a convenience form of ignore that matches the same style as demand. E.g. instead of mock.ignore('hasNext') you can use mock.ignore.hasNext(). A Closure variation is also provided. This convenience shorthand only applies to the String form of ignore and cannot be used with methods from java.lang.Object. Be careful using this feature while mocking some of the fundamental Java classes like String or Pattern. As these are used within the implementation of the ignore capability, strange behavior may be observed.


makeProxyInstance

GroovyObject makeProxyInstance(def args, boolean isDelegate)


proxyDelegateInstance

GroovyObject proxyDelegateInstance(def args = null)
Allows a more traditional instance-style mocking paradigm. This is the recommended method to call to use the instance-style with Java classes. When mocking interfaces or abstract classes, a compatible proxy instance will be returned. When mocking Java classes, a compatible Groovy class will be generated and proxy instance returned. A MockProxyMetaClass will be instantiated for the class of the instance (i.e. may be on the generated class not the original class).


proxyInstance

GroovyObject proxyInstance(def args = null)
Allows a more traditional instance-style mocking paradigm. This is the recommended method to call to use the instance-style with Groovy classes. When mocking interfaces or abstract classes, a compatible proxy instance will be returned. When mocking Java classes, a compatible Groovy class will be generated and proxy instance returned. A MockProxyMetaClass will be instantiated for the original class. Typical example:
 import groovy.mock.interceptor.MockFor

 class Person {
   String first, last
 }

 class Family {
   Person mother, father
   String nameOfMother() { fullName(mother) }
   String nameOfFather() { fullName(father) }
   private fullName(p) { "$p.first $p.last" }
 }

 def mock = new MockFor(Person)
 mock.demand.with {
   getFirst{ 'dummy' }
   getLast{ 'name' }
 }
 Person john = mock.proxyInstance()
 Person mary = mock.proxyInstance()
 Family f = new Family(father:john, mother:mary)
 assert f.nameOfFather() == 'dummy name'
 assert f.nameOfMother() == 'dummy name'
 [john, mary].each{ mock.verify(it) }
 
Normally for mocks, verify() is call automatically at the end of the "use" Closure, but with this style, no "use" Closure is present, so verify() must be called manually.


use

void use(Closure closure)
Identifies the Closure where the mocked collaborator behavior will be applied and verified.


use

void use(GroovyObject obj, Closure closure)


verify

void verify(GroovyObject obj)
If manual verification is required


 

Copyright © 2003-2013 The Codehaus. All rights reserved.