Grails 1.1 Testing - Unit, Integration & Functional

Grails 1.1 Testing
Tech Talk @ 2Paths
July 17, 2009
By Dave Koo
©2009 - 2Paths Solutions Ltd. (www.2paths.com)
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Agenda
Unit Testing
Integration Testing
Functional Testing
Putting It All Together
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Unit Testing - Overview
unit tests enable testing small bits of code in isolation
Grails does NOT inject any surrounding infrastructure (ie. no dynamic GORM methods, database, Spring resources, bootstrap, ServletContext, etc)
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Unit Testing - Benefits
find problems sooner -> you can test your code before all it's dependencies are created/available
enables safer refactoring (of individual classes)
faster to run than integration & functional tests
there isn't a big speed gap early in the project (PLAID: unit ~ 10s, integration ~ 30)
but it grows as the system gets bigger
makes TDD less painful -> breaks problem into smaller pieces
provides form of API documentation & spec
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Unit Testing - Drawbacks
more code to maintain & debug -> often as buggy as code under test (if written by same person :)
sometimes you have to mock a LOT of stuff before you can write your little test
doesn't catch bugs at the integration or UI layers -> can create false sense of security
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Unit Testing – GrailsUnitTestCaseOverview
extends GroovyTestCase to add Grails-specific mocking and make testing more convenient for Grails users
mocking is test-specific and doesn't leak from one test to another
avoids having to do a lot of MetaClass hacking (and forgetting to teardown your metaclass hacking :)
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Unit Testing – GrailsUnitTestCasemethods
mockFor(class, loose = false)
mockDomain(class, testInstances[ ])
mockForConstraintsTests(class, testInstances[ ])
mockLogging(class, enableDebug = false)
Code samples: http://grails.org/doc/1.1.1/guide/9.%20Testing.html#9.1%20Unit%20Testing
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Unit Testing – GrailsUnitTestCasemockFor(class, loose = false)
generic mocker for mocking methods of any class
returns a control object (not the actual mock)
loose - false == strict mocking (sequence of expected method calls matters), true == loose (sequence doesn't matter)
methods - you can mock instance or static methods
demands - your expectations of the mock
range - number of times a method is expected to be called (default === 1)
closure - mock implementation of the method
strictControl.createMock() - returns an actual mock object
strictControl.verify() - verifies that all demands were actually met
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Unit Testing – GrailsUnitTestCasemockDomain(class, testInstances[ ])
mocks all methods (instance, static & dynamic) on a domain class
testInstances- a list of domain class instances which replaces and acts as the "database”
you can call save(), findBy*(), validate(), etc on an instance of a mocked domain class
inheritance can be tricky!
assume you have ParentClass, ChildA, ChildB
if you mock ParentClass and pass a collection of instances containing ChildA and/or ChildB objects to the MockDomain() method, you must ensure that you have already mocked each type of ChildX class in the instance collection. This is needed even if you NEVER call a dynamic method on any child class (such as ChildClass.list()).
always mock a child class BEFORE mocking its parent, otherwise you may get "Method Not Found" exceptions when calling dynamic methods on the child
new addition to Grails
still some bugs / missing features
check Grails' JIRA & mailing lists if experiencing wierdbehaviour
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Unit Testing – GrailsUnitTestCaseother methods…
mockForConstraintsTests(class, testInstances[ ])
Stripped-down version of mockDomain that allows for assertions to validate domain class constraints
Takes the pain out of testing domain class constraints
mockLogging(class, enableDebug = false)
Adds a mock "log" property to a class. Any messages passed to the mock logger are echoed to the console.
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Unit Testing – ControllerUnitTestCase
extends GrailsUnitTestCase to add mocks for:
all dynamic properties & methods Grails injects into controllers (render, redirect, model, etc)
all HTTP objects available to controllers (request, response, session, params, flash, etc)
command object (if needed)
provides an implicit "controller" property which contains all the above mocks (no need to def the controller yourself in your test class)
don't forget to mock your Domain objects as needed if the controller action you call expects a database
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Unit Testing – Other Unit Tests
TagLibUnitTestCase
extends GrailsUnitTestCase to add mocks for dynamic properties & methods a TagLibexpects
dbUnit
extends jUnit to allow you to test that your DB is in the expected state
prevents subsequent tests from failing due to a previous test leaving the database "dirty"
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Integration Testing - Overview
used to test that an entire module or sub-system consisting of multiple classes is working correctly (in isolation)
one level below a functional test as integration tests do not test the entire stack
Grails injects all the surrounding infrastructure such as data sources & Spring beans
pretty straightforward to implement since there's generally no mocking involved
where to use integration tests??? we'll come back to this in a few mins :)
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Integration Testing - Benefits
tests the real interactions between individual pieces
finds more complex bugs that unit tests can't find
faster to run than functional tests (usually)
makes large-scale refactoring safer
find bugs sooner -> doesn't require other system modules to be built
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Integration Testing - Drawbacks
perhaps overused by lazy testers who don't feel like mocking :)
requires more code to be written than unit tests
doesn't find system-level or inter-module bugs
value is debatable if you have good functional tests & good unit tests.
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Functional Testing - Overview
used to test functionality from an end user's perspective across all layers of the system
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Functional Testing - Benefits
finds complex system-level and inter-module bugs
finds UI bugs
can be written by non-techies (depends on tool used)
provides "done when" acceptance criteria for the customer
provides a form of user documentation
makes large-scale refactoring safer
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Functional Testing - Drawbacks
very slow to execute HTTP level tests
often more cumbersome to write than other types of tests
often brittle and can require a lot of maintenance (especially if tied to UI)
Usually hard to write until UI is available (and stable)
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Functional Testing - Tools
CanooWebTest& Grails Functional Testing
Both wrap HtmlUnit which provides a Java API that mocks a web browser
CanooWebTest
wrapper for WebTest's XML syntax
and therefore constrained by the underlying XML syntax
Grails Functional Testing
pure-groovy solution
more flexible, but newer & therefore fewer features than WebTest
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Functional Testing - WebTest
test organization & re-use
grouping steps with ant.group
calling methods from other tests
Groovy step
notation uses 3 double-quotes as Groovy code delimeter (“””)
accessing HtmlUnit for fine-grained test control
parameter passing between app context & WebTest context
AJAX testing w/ sleep()
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Functional Testing – WebTestgrouping steps with ant.group
if your test has dozens of steps, it gets hard to read the report
grouping steps with ant.group rolls them up to 1 line in the test report, which can be easily expanded/collapsed:
ant.group(description: “verify bank account info”) { invoke “someController/someAction”verifyText “some text”verifyText “more text”}
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Functional Testing – WebTestcalling methods from other tests
Instead of copying & pasting the same methods from one test to another, you can call a method in another test by passing it your AntBuilder instance (ant) as a param. This ensures the test steps are executed using the calling test’s AntBuilder.
====== in CallingTestClass() ====def otherTestClass = new OtherTestClass()otherTestClass.someMethod(ant)====== in OtherTestClass() =====def someMethod(AntBuilderab) {ab.invoke“someController/someAction”ab.verifyText“some text”}
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Functional Testing – WebTestGroovy step
If you need to execute arbitrary Groovy code in your test, use WebTest’sgroovy step.
Keep in mind that this groovy step won’t have access to any Groovy variables defined in your test (such as method params)…it only has access to the properties in the AntBuilder context.
So you need to pass any needed params to the AntBuilder before entering your groovy step. Then you can retrieve them from the AntBuilder from within your step.
The following example involves:
Storing Groovy variables into AntBuilder properties
Retrieving AntBuilder properties for use in the Groovy step
Calling some HtmlUnit methods which aren’t available in WebTest for fine-grained test control
Pausing the test for 2 seconds (very useful with AJAX tests to give the server time to respond
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Functional Testing – WebTestGroovy step
test method with Groovy step to test AJAX autocomplete form input:
def setAJAXInputField(elementId, elementValue, AntBuilderab) {ab.storeProperty(property: 'elementId', value: elementId)
ab.storeProperty(property: 'elementValue', value: elementValue)
ab.groovy ""” def elementId = step.webtestProperties.elementId
def elementValue = step.webtestProperties.elementValue def document = step.context.currentResponse.documentElement
def element = document.getHtmlElementById(elementId)
element.focus()
element.type(elementValue)
Thread.sleep(2000)“””
}
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Putting It All Together - Running tests
test-app -> all tests
test-app -unit -> all unit tests
test-app -integration -> all integration tests
test-app -unit AnnualReportAssignmentHandler-> 2 unit tests & all integration tests
test-app AnnualReportAssignmentHandlerWorkflowManagerService-> 2 unit tests & 1 integration test
run-webtest-> runs all tests using new server instance
run-webtest -nostart-> runs all tests using existing Tomcat instance (much faster!!!)
run-webtestClassNameTestName-> run TestName using existing Tomcat instance
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Putting It All Together - Summary
Unit testing - taglibs, controllers, services, domain classes (including contraints), other delegates & "helpers", even your data (dbUnit)
Integration testing
now that Grails 1.1 supports unit testing of controllers with ControllerUnitTestCase, that seems to be the preferred way of testing them (rather than using integration tests).
This makes sense since controllers should not be doing the heavy lifting in a Grails app.
The same holds true for TagLib testing with TagLibUnitTestCase.
this leaves Services as the most valuable thing to cover with integration tests (but only after you’ve written unit tests for them )
Functional testing - smoke tests, acceptance tests, regression tests
Manual testing by humans - look & feel, anything not covered above
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