I am working on a shared library for Jenkins, and I want to access some utilities methods between some classes, but not all of them, thus I have established some statements:
I would like to avoid using static methods, since it does not access pipeline steps directly, and passing the pipeline instance every call would be a pain;
I would like to avoid a singleton as well, or prefixing every method call with the util class' instance;
Since it is not supposed to be shared between all classes I would like to avoid putting every method as a file on vars/ special directory, but I would like a similar behavior;
Despite extending the class would be a anti-pattern, it would be acceptable, though I would like to avoid the verbose Java syntax for declaring the class the same name as the file, once it is implicit in groovy;
This question does solve my problem partially, although there are issues with serialization, I noted that when I use checkpoint and some build is resumed from some stage, the instance loses all extra methods.
This other question would have helped me fix the serialization issue, however the author seems the have solved the root cause of his problem using a way that is not the original question titled for.
Is there a way to extends a implicit script class in groovy without using the class NameOfFile extends SomeOtherClass { put every thing inside this block } syntax? And without working with inner-class?
Or else, is there a way to declare a constructor using the script groovy syntax analogue as the previous question?
Or even, is there a way to change the serialization behavior to install the extra methods again after unserializing?
Appendix
The script syntax works more-or-less like this:
Consider the content of file src/cicd/pipeline/SomePipeline.groovy:
package cicd.pipeline
// there is no need to wrap everything inside class SomePipeline,
// since it is implicit
def method() {
// instance method, here I can access pipeline steps freely
}
def static otherMethod() {
// static method, here it is unable to access pipeline steps
// without a instance
}
#groovy.transform.Field
def field
def call() {
// if the class is used as method it will run
this.method()
SomePipeline.otherMethod() // or simply otherMethod() should work
this.field = 'foo'
println "this instance ${this.getClass().canonicalName} should be cicd.pipeline.SomePipeline"
}
// any code other than methods or variables with #Field
// annotation will be inside a implicit run method that is
// triggered likewise main method but isn't a static one
def localVar = 'foo'
println "It will not execute on constructor since it is on run: $localVar"
println "Method: ${org.codehaus.groovy.runtime.StackTraceUtils.sanitize(new Throwable()).stackTrace[0].methodName}"
println "this instance ${this.getClass().canonicalName} should be cicd.pipeline.SomePipeline"
If I was going to use the Java verbose syntax I would have to wrap almost everything inside a class SomePipeline which is implicit in groovy, this is the script syntax I want to keep.
I realised that this.getClass().superclass.canonicalName when outside Jenkins pipeline is groovy.lang.Script and when inside pipeline is org.jenkinsci.plugins.workflow.cps.CpsScript and based on this resource I was able to elaborate the following solution:
abstract class CustomScript extends org.jenkinsci.plugins.workflow.cps.CpsScript {
public CustomScript() {
// do something here, it will always execute regardless
// serialization, and before everything
}
}
#groovy.transform.BaseScript CustomScript baseScript
That is it, worked as expected! Of course you can elaborate this solution better in order to reduce repeating and avoid inner-classes, but I will leave it for your imagination.
Related
I am able to declare a class instance as global like this :
gitUtils = new GitUtils()
pipeline {
...
echo "hello: " + gitUtils.doSomething()
}
But if the pipeline calls a function defined as groovy script in "vars" directory, gitUtils is not visible anymore
def call() {
def something = gitUtils.doSomething()
}
I also tryed to use #Field but it changes nothing. Note that all the pipeline is defined in the shared library (project jenkinsfile just calls a function from this shared library).
How to access gitUtils from groovy scripts in /vars in this example ?
I know we could pass the instance as parameter of function declared in /vars but more you have functions using you utilitary class, more it is ugly. Would you imagine to pass 'echo' or 'sh' function as parameter ? No, here is the same.
I know we could not use at all classes defined in src and define groovy script with multiple public methods. Here we could imagine create in /vars a gitutils.groovy with many public method. But this would imply to use 'script' closure in the pipeline to choose which method we want, like this:
script {
gitutils.doSomething()
}
I dont want this. I would pref to create a single function per groovy script in /vars. Thus, we can call them directly in steps, like this:
steps {
myGroovyScriptFunction()
}
But by doing such, the number of function increase and functions are not organized correctly. That is why the idea is to create "big step function" in /vars which use inside more generic functions, from instances of classes (even static in the better case). So, instead of creating a new instance in each groovy script, I would like a global instance.
Context: declarative pipeline, openshift jenkins, slave with dynamic pod template
It's not possible because of JENKINS-42360.
The best way to use global steps without a script block is in my opinion to define an instance of GitUtils and use it directly in the global steps. If you need the pipeline step context you can pass it to the constructor:
# vars/myStep.groovy
import my.packagename.GitUtils
def call() {
GitUtils gitUtils = new GitUtils(steps)
...
}
then you can use the steps with inside GitUtils as described here. Remember to define GitUtils to implement Serializable as per documentation.
I am aware that a variable can be dynamically typed with the def keyword in Groovy. But I have also noticed that in some circumstances it can be left out, such as when defining method parameters, eg func(p1, p2) instead of func(def p1, def p2). The latter form is discouraged.
I have noticed that this is extendable to all code - anytime you want to define a variable and set its value, eg var = 2 the def keyword can be safely left out. It only appears to be required if not instantiating the variable on creation, ie. def var1 so that it can be instantiated as a NullObject.
Is this the only time def is useful? Can it be safely left out in all other declarations, for example, of classes and methods?
Short answer: you can't. There are some use cases where skipping the type declaration (or def keyword) works, but it is not a general rule. For instance, Groovy scripts allow you to use variables without specific type declaration, e.g.
x = 10
However, it works because groovy.lang.Script class implements getProperty and setProperty methods that get triggered when you access a missing property. In this case, such a variable is promoted to be a global binding, not a local variable. If you try to do the same on any other class that does not implement those methods, you will end up getting groovy.lang.MissingPropertyException.
Skipping types in a method declaration is supported, both in dynamically compiled and statically compiled Groovy. But is it useful? It depends. In most cases, it's much better to declare the type for a better readability and documentation purpose. I would not recommend doing it in the public API - the user of your API will see Object type, while you may expect some specific type. It shows that this may work if your intention is to receive any object, no matter what is its specific type. (E.g. a method like dump(obj) could work like that.)
And last but not least, there is a way to skip type declaration in any context. You can use a final keyword for that.
class Foo {
final id = 1
void bar(final name) {
final greet = "Hello, "
println greet + name + "!"
}
}
This way you can get a code that compiles with dynamic compilation, as well as with static compilation enabled. Of course, using final keyword prevents you from re-assigning the variable, but for the compiler, this is enough information to infer the proper type.
For more information, you can check a similar question that was asked on SO some time ago: Groovy: "def" keyword vs concrete type
in Groovy it plays an important role in Global and Local variable
if the variable name is same with and without def
def is considered local and without def its global
I have explained here in detail https://stackoverflow.com/a/45994227/2986279
So if someone use with and without it will make a difference and can change things.
Thanks in advance for the help -
I am new to mockito but have spent the last day looking at examples and the documentation but haven't been able to find a solution to my problem, so hopefully this is not too dumb of a question.
I want to verify that deleteLogs() calls deleteLog(Path) NUM_LOGS_TO_DELETE number of times, per path marked for delete. I don't care what the path is in the mock (since I don't want to go to the file system, cluster, etc. for the test) so I verify that deleteLog was called NUM_LOGS_TO_DELETE times with any non-null Path as a parameter. When I step through the execution however, deleteLog gets passed a null argument - this results in a NullPointerException (based on the behavior of the code I inherited).
Maybe I am doing something wrong, but verify and the use of isNotNull seems pretty straight forward...here is my code:
MonitoringController mockController = mock(MonitoringController.class);
// Call the function whose behavior I want to verify
mockController.deleteLogs();
// Verify that mockController called deleteLog the appropriate number of times
verify(mockController, Mockito.times(NUM_LOGS_TO_DELETE)).deleteLog(isNotNull(Path.class));
Thanks again
I've never used isNotNull for arguments so I can't really say what's going wrong with you code - I always use an ArgumentCaptor. Basically you tell it what type of arguments to look for, it captures them, and then after the call you can assert the values you were looking for. Give the below code a try:
ArgumentCaptor<Path> pathCaptor = ArgumentCaptor.forClass(Path.class);
verify(mockController, Mockito.times(NUM_LOGS_TO_DELETE)).deleteLog(pathCaptor.capture());
for (Path path : pathCaptor.getAllValues()) {
assertNotNull(path);
}
As it turns out, isNotNull is a method that returns null, and that's deliberate. Mockito matchers work via side effects, so it's more-or-less expected for all matchers to return dummy values like null or 0 and instead record their expectations on a stack within the Mockito framework.
The unexpected part of this is that your MonitoringController.deleteLog is actually calling your code, rather than calling Mockito's verification code. Typically this happens because deleteLog is final: Mockito works through subclasses (actually dynamic proxies), and because final prohibits subclassing, the compiler basically skips the virtual method lookup and inlines a call directly to the implementation instead of Mockito's mock. Double-check that methods you're trying to stub or verify are not final, because you're counting on them not behaving as final in your test.
It's almost never correct to call a method on a mock directly in your test; if this is a MonitoringControllerTest, you should be using a real MonitoringController and mocking its dependencies. I hope your mockController.deleteLogs() is just meant to stand in for your actual test code, where you exercise some other component that depends on and interacts with MonitoringController.
Most tests don't need mocking at all. Let's say you have this class:
class MonitoringController {
private List<Log> logs = new ArrayList<>();
public void deleteLogs() {
logs.clear();
}
public int getLogCount() {
return logs.size();
}
}
Then this would be a valid test that doesn't use Mockito:
#Test public void deleteLogsShouldReturnZeroLogCount() {
MonitoringController controllerUnderTest = new MonitoringController();
controllerUnderTest.logSomeStuff(); // presumably you've tested elsewhere
// that this works
controllerUnderTest.deleteLogs();
assertEquals(0, controllerUnderTest.getLogCount());
}
But your monitoring controller could also look like this:
class MonitoringController {
private final LogRepository logRepository;
public MonitoringController(LogRepository logRepository) {
// By passing in your dependency, you have made the creator of your class
// responsible. This is called "Inversion-of-Control" (IoC), and is a key
// tenet of dependency injection.
this.logRepository = logRepository;
}
public void deleteLogs() {
logRepository.delete(RecordMatcher.ALL);
}
public int getLogCount() {
return logRepository.count(RecordMatcher.ALL);
}
}
Suddenly it may not be so easy to test your code, because it doesn't keep state of its own. To use the same test as the above one, you would need a working LogRepository. You could write a FakeLogRepository that keeps things in memory, which is a great strategy, or you could use Mockito to make a mock for you:
#Test public void deleteLogsShouldCallRepositoryDelete() {
LogRepository mockLogRepository = Mockito.mock(LogRepository.class);
MonitoringController controllerUnderTest =
new MonitoringController(mockLogRepository);
controllerUnderTest.deleteLogs();
// Now you can check that your REAL MonitoringController calls
// the right method on your MOCK dependency.
Mockito.verify(mockLogRepository).delete(Mockito.eq(RecordMatcher.ALL));
}
This shows some of the benefits and limitations of Mockito:
You don't need the implementation to keep state any more. You don't even need getLogCount to exist.
You can also skip creating the logs, because you're testing the interaction, not the state.
You're more tightly-bound to the implementation of MonitoringController: You can't simply test that it's holding to its general contract.
Mockito can stub individual interactions, but getting them consistent is hard. If you want your LogRepository.count to return 2 until you call delete, then return 0, that would be difficult to express in Mockito. This is why it may make sense to write fake implementations to represent stateful objects and leave Mockito mocks for stateless service interfaces.
I am using groovy to create some mock classes for a test case. I am basically creating dummy objects where all the methods return null so that i can run my testcase.
I am using the following syntax:
MessageFactory.instance = ["getMessage": {a,b,c,d -> "dummy"}] as MessageFactory
So here i am trying to overwrite the singleton instance with my on fake factory object. The problem is that MessageFactory's constructor happens to be a private method. This gives me an illigal access exception when i run the code above. Is there a away i can create a proxy in groovy and overcome the private constructor issue?
If you have access to the MessageFactory, and are willing to modify it, then you use the standard dependency-injection solution, as detailed here: mock singleton
..Though it's not particularly Groovy.
Otherwise, the best workaround I've found is to override the method(s) on the singleton instance itself, like so:
#Singleton
class Test{
def method(){"Unmocked method called"}
}
def test = Test.instance
test.metaClass.method = {-> null}
test.method() // Now returns null
Naturally, as a singleton, this instance doesn't change (at least in theory)... So, overriding methods in this manner is effectively global.
Edit: Or you can use GMock, which supports constructor mocking (among other things).
In my attempt to mock an object in Groovy using the mock.interceptor package:
def mock = new MockFor(TheClass);
mock.demand.theMethod{ "return" }
mock.use {
def underTest = new TheClass()
println underTest.theMethod()
}
The problem I have is when creating TheClass() in the use{ block, it uses the actual constructor which, in this circumstance, I'd rather it not use. How can I create an instance of this class so I can test the method I do care about, theMethod, without needing to use the constructor?
Using EasyMock/CE, mocks can be made without using the constructor, but am curious how to achieve that in Groovy.
I recently saw a presentation by the author of GMock and it has some hooks to allow "constructor" mocking which I think is what you are after.
e.g.
def mockFile = mock(File, constructor('/a/path/file.txt'))
This library differs from that "built in" to groovy, however it looked very well written, with some thought put into the kinds of things you want to mock and more importantly the error messages you would get when tests should fail.
I think this is what you are after. I would say use constructor mocking with care - it could be a smell that you should inject a Factory object, but for some things it looked to work well.
You can use the interceptConstruction flag when calling MockFor, see
MockFor.