I am developing cucumber scenarios using Cucumber JVM (Groovy) in intellij. Things are much better than doing the same in eclipse I must say.
I'd like to resolve one small problem to make things even better for my team. But since I am new to Intellij, I need help with the following please:
When I am in a step def file (groovy), Intellij can't seem to see variables and methods defined in the cucumber "World" object. So don't get IDE support (auto-complete, etc) for those which is a bit annoying. How can I fix that?
IntelliJ IDEA expects an object inside World closure. So, you could define the folloing block in EACH step definitions file:
World {
new MockedTestWorld()
}
MockedTestWorld.groovy:
class MockedTestWorld implements TestWorld {
#Lazy
#Delegate
#SuppressWarnings("GroovyAssignabilityCheck")
private TestWorld delegate = {
throw new UnsupportedOperationException("" +
"Test world mock is used ONLY for syntax highlighting in IDE" +
" and must be overridden by concrete 'InitSteps.groovy' implementation.")
}()
}
To cleanup duplicated world definitions we use last-glue initializers and a bit of copy-paste:
real/InitSteps.groovy
def world
GroovyBackend.instance.#worldClosures.clear()
GroovyBackend.instance.registerWorld {
return world ?: (world = new RealTestWorld1()) // Actual initialization is much longer
}
legacy/InitSteps.groovy
def world
GroovyBackend.instance.#worldClosures.clear()
GroovyBackend.instance.registerWorld {
return world ?: (world = new LegacyTestWorld1())
}
Finally, run configurations would be like this (with different glues):
// Real setup
glue = { "classpath:test/steps", "classpath:test/real", },
// Legacy setup
glue = { "classpath:test/steps", "classpath:test/legacy", },
Related
What is the use of the static initialization block in Groovy. Why does Geb use it? If the use of it is the same as in Java, then how can you initialize non-declared fields in a situtation like this?
class ManualsMenuModule extends Module {
static content = {
toggle { $("div.menu a.manuals") }
linksContainer { $("#manuals-menu") }
links { linksContainer.find("a") }
}
void open() {
toggle.click()
waitFor { !linksContainer.hasClass("animating") }
}
}
Some answers to your questions are provided in the section about the content DSL of the Geb manual.
The DSL is implemented using Groovy's methodMissing() mechanism and modification of the delegate of the closure assigned to the static content field. If you are interested in digging deeper then you can always look at the implementation in PageContentTemplateBuilder.
I'm not expert on Geb, I can only explain the groovy meaning of the code.
1st off, it's not the static initialization block like in java. In those lines static content = {...} you are assigning to a static variable a Closure instance which is evaluated and executed LATER (hence, lazy).
The closure represents a (part of) a Geb's Groovy Builder which is called by Geb framework to register/perform some tasks.
There's no Java counterpart to achieve the same, and that's the reason why groovy-based frameworks are so nice to use for testing purposes and they follow the general rule of thumb:
test code should be more abstract then the code under test
UPDATE:
This line:
toggle { $("div.menu a.manuals") }
can be rewritten like
toggle( { $("div.menu a.manuals") } )
or
def a = { $("div.menu a.manuals") }
toggle a
so it's a method invocation and not an assignment. In groovy you can omit the brackets in some cases.
How to reuse code block which describe similiar ant build logic in groovy?
If we have build logic which was implemented by Groovy AntBuilder, just like code below:
ant.someTask(attr1:value1, attr2:value2) {
configuration1(param1:args1, param2:args2){
similiarStructure(additionalArgs:aaa){
setting1(param5:value5) {
//...blah blah blah
}
//further more settings, may be or may be not the same with similiarStructure below
}
}
configuration2(param3:args3, param4:args4){
similiarStructure(additionalArgs:aaa){
setting1(param5:value5) {
//...blah blah blah
}
//further more settings, may be or may be not the same with similiarStructure below
}
}
}
Are there any ways to reuse Groovy AntBuilder code block, which could brief the statment in configuration2 ?
I've try to predefine closures and inject them in both configuration,
but it fails with property not found exception while initializing closure.
I'll provide two answers so you can select which one is more appropriate for your use case and test it. The solutions depend on at what level you want the shared config.
If you want a more general purpose solution that allows you to share the whole of the similarStructure block, you need to perform some more advanced work. The trick is to ensure that the delegate of the shared configuration closure is set appropriately:
def sharedConfig = {
similarStructure(additionalArgs:aaa) {
setting1(param5:value5) {
//...blah blah blah
}
}
}
ant.someTask(attr1: value1, attr2: value2) {
configuration1(param1:args1, param2:args2){
applySharedConfig(delegate, sharedConfig)
}
configuration2(param3:args3, param4:args4){
applySharedConfig(delegate, sharedConfig)
}
}
void applySharedConfig(builder, config) {
def c = config.clone()
c.resolveStrategy = Closure.DELEGATE_FIRST
c.delegate = builder
c.call()
}
Although the applySharedConfig() method seems ugly, it can be used to share multiple configurations across different tasks.
One thing to bear in mind with this solution is that the resolveStrategy of the closure can be very important. I think both DELEGATE_FIRST and OWNER_FIRST (the default) will work fine here. If you run into what appear to be name resolution problems (missing methods or properties) you should try switching the resolution strategy.
I'll provide two answers so you can select which one is more appropriate for your use case and test it. The solutions depend on at what level you want the shared config.
If you are happy to simply share the closure that goes with similarStructure, then the solution is straightforward:
def sharedConfig = {
setting1(param5:value5) {
//...blah blah blah
}
}
ant.someTask(attr1: value1, attr2: value2) {
configuration1(param1:args1, param2:args2) {
similarStructure(additionalArgs:aaa, sharedConfig)
}
configuration2(param3:args3, param4:args4) {
similarStructure(additionalArgs:aaa, sharedConfig)
}
}
The method that is similarStructure should ensure that the sharedConfig closure is properly configured. I haven't tested this, so I'm not entirely sure. The disadvantage of this approach is that you have to duplicate the similarStructure call with its arguments.
One of the cool new C++ features in Visual Studio 2010 are lambda expressions. However, I can't get them to work within a managed class.
class UnmanagedClass {
void Foo() {
// Creating empty lambda within unmanaged class.
// This compiles fine.
auto lambda = [](){ ; };
}
};
ref class ManagedClass {
void Foo() {
// Creating empty lambda within managed class.
// This creates error C3809:
// A managed type cannot have any friend functions/classes/interfaces.
auto lambda = [](){ ; };
}
};
My best guess is that the compiler creates the anonymous function class as a friend class, even though I never use class members. This seems to mean that lambdas cannot be used at all within ref classes.
I was so happy when I read that VS2010 adds lambda expressions to C++. Does anybody know how to get them to work within ref classes?
Looks like it is being considered for future versions. Otherwise known as: "We'll get to it."
I have an application which can run scripts to automate certain tasks. I'd like to use meta programming in these scripts to optimize code size and readability. So instead of:
try {
def res = factory.allocate();
... do something with res ...
} finally {
res.close()
}
I'd like to
Factory.metaClass.withResource = { c ->
try {
def res = factory.allocate();
c(res)
} finally {
res.close()
}
}
so the script writers can write:
factory.withResource { res ->
... do something with res ...
}
(and I could do proper error handling, etc).
Now I wonder when and how I can/should implement this. I could attach the manipulation of the meta class in a header which I prepend to every script but I'm worried what would happen if two users ran the script at the same time (concurrent access to the meta class).
What is the scope of the meta class? The compiler? The script environment? The Java VM? The classloader which loaded Groovy?
My reasoning is that if Groovy meta classes have VM scope, then I could run a setup script once during startup.
Metaclasses exist per classloader [citation needed]:
File /tmp/Qwop.groovy:
class Qwop { }
File /tmp/Loader.groovy:
Qwop.metaClass.bar = { }
qwop1 = new Qwop()
assert qwop1.respondsTo('bar')
loader = new GroovyClassLoader()
clazz = loader.parseClass new File("/tmp/Qwop.groovy")
clazz.metaClass.brap = { 'oh my' }
qwop = clazz.newInstance()
assert !qwop.respondsTo('bar')
assert qwop1.respondsTo('bar')
assert qwop.brap() == "oh my"
assert !qwop1.respondsTo('brap')
// here be custom classloaders
new GroovyShell(loader).evaluate new File('/tmp/QwopTest.groovy')
And a script to test the scoped metaclass (/tmp/QwopTest.groovy):
assert !new Qwop().respondsTo('bar')
assert new Qwop().respondsTo('brap')
Execution:
$ groovy Loaders.groovy
$
If you have a set of well defined classes you could apply metaprogramming on top of the classes loaded by your classloader, as per the brap method added.
Another option for this sort of thing which is better for a lot of scenarios is to use an extension module.
package demo
class FactoryExtension {
static withResource(Factory instance, Closure c) {
def res
try {
res = instance.allocate()
c(res)
} finally {
res?.close()
}
}
}
Compile that and put it in a jar file which contains a file at META-INF/services/org.codehaus.groovy.runtime.ExtensionModule that contains something like this...
moduleName=factory-extension-module
moduleVersion=1.0
extensionClasses=demo.FactoryExtension
Then in order for someone to use your extension they just need to put that jar file on their CLASSPATH. With all of that in place, a user could do something like this...
factoryInstance.withResource { res ->
... do something with res ...
}
More information on extension modules is available at http://docs.groovy-lang.org/docs/groovy-2.3.6/html/documentation/#_extension_modules.
As new to groovy...
I'm trying to replace the java idiom for event listeners, filters, etc.
My working code in groovy is the following:
def find() {
ODB odb = ODBFactory.open(files.nodupes); // data nucleus object database
Objects<Prospect> src = odb.getObjects(new QProspect());
src.each { println it };
odb.close();
}
class QProspect extends SimpleNativeQuery {
public boolean match(Prospect p) {
if (p.url) {
return p.url.endsWith(".biz");
}
return false;
}
}
Now, this is far from what I'm used to in java, where the implementation of the Query interface is done right inside the odb.getObjects() method. If I where to code "java" I'd probably do something like the following, yet it's not working:
Objects<Prospect> src = odb.getObjects( {
boolean match(p) {
if (p.url) {
return p.url.endsWith(".biz");
}
return false;
}
} as SimpleNativeQuery);
Or better, I'd like it to be like this:
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
However, what groovy does it to associate the "match" method with the outer script context and fail me.
I find groovy... groovy anyways so I'll stick to learning more about it. Thanks.
What I should've asked was how do we do the "anonymous" class in groovy. Here's the java idiom:
void defReadAFile() {
File[] files = new File(".").listFiles(new FileFilter() {
public boolean accept(File file) {
return file.getPath().endsWith(".biz");
}
});
}
Can groovy be as concise with no additional class declaration?
I think it would have helped you to get answers if you'd abstracted the problem so that it didn't rely on the Neodatis DB interface -- that threw me for a loop, as I've never used it. What I've written below about it is based on a very cursory analysis.
For that matter, I've never used Groovy either, though I like what I've seen of it. But seeing as no one else has answered yet, you're stuck with me :-)
I think the problem (or at least part of it) may be that you're expecting too much of the SimpleNativeQuery class from Neodatis. It doesn't look like it even tries to filter the objects before it adds them to the returned collection. I think instead you want to use org.neodatis.odb.impl.core.query.criteria.CriteriaQuery. (Note the "impl" in the package path. This has me a bit nervous, as I don't know for sure if this class is meant to be used by callers. But I don't see any other classes in Neodatis that allow for query criteria to be specified.)
But instead of using CriteriaQuery directly, I think you'd rather wrap it inside of a Groovy class so that you can use it with closures. So, I think a Groovy version of your code with closures might look something like this:
// Create a class that wraps CriteriaQuery and allows you
// to pass closures. This is wordy too, but at least it's
// reusable.
import org.neodatis.odb.impl.core.query.criteria;
class GroovyCriteriaQuery extends CriteriaQuery {
private final c;
QProspect(theClosure) {
// I prefer to check for null here, instead of in match()
if (theClosure == null) {
throw new InvalidArgumentException("theClosure can't be null!");
}
c = theClosure;
}
public boolean match(AbstractObjectInfo aoi){
//!! I'm assuming here that 'aoi' can be used as the actual
//!! object instance (or at least as proxy for it.)
//!! (You may have to extract the actual object from aoi before calling c.)
return c(aoi);
}
}
// Now use the query class in some random code.
Objects<Prospect> src = odb.getObjects(
new GroovyCriteriaQuery(
{ it.url.endsWith(".biz") }
)
)
I hope this helps!
I believe your real question is "Can I use closures instead of anonymous classes when calling Java APIs that do not use closures". And the answer is a definite "yes". This:
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
should work. You write "However, what groovy does it to associate the "match" method with the outer script context and fail me". How exactly does it fail? It seems to me like you're having a simple technical problem to get the solution that is both "the groovy way" and exactly what you desire to work.
Yep, thanks y'all, it works.
I also found out why SimpleNativeQuery does not work (per Dan Breslau).
I tried the following and it worked wonderfully. So the idiom does work as expected.
new File("c:\\temp").listFiles({ it.path.endsWith(".html") } as FileFilter);
This next one does not work because of the neodatis interface. The interface does not enforce a match() method! It only mentions it in the documentation yet it's not present in the class file:
public class SimpleNativeQuery extends AbstactQuery{
}
Objects<Prospect> src = odb.getObjects(
{ it.url.endsWith(".biz") } as SimpleNativeQuery
);
In the above, as the SimpleNativeQuery does not have a match() method, it makes it impossible for the groovy compiler to identify which method in the SimpleNativeQuery should the closure be attached to; it then defaults to the outer groovy script.
It's my third day with groovy and I'm loving it.
Both books are great:
- Groovy Recipes (Scott Davis)
- Programming Groovy (Venkat Subramaniam)