Strange behavior of gorm finder - grails

In a controller I have this finder
User.findByEmail('test#test.com')
And works.
Works even if I write
User.findByEmail(null)
But if i write
User.findByEmail(session.email)
and session.email is not defined (ergo is null) it throw exception
groovy.lang.MissingMethodException: No signature of method: myapp.User.findByEmail() is applicable for argument types: () values: []
Is this behavior right?
If i evaluate "session.email" it give me null so I think it must work as it do when I write
User.findByEmail(null)
Even more strange....
If I run this code in groovy console:
import myapp.User
User.findByEmail(null)
It return a user that has null email but if I run the same code a second time it return
groovy.lang.MissingMethodException: No signature of method: myapp.User.findByEmail() is applicable for argument types: () values: []

You can't use standard findBySomething dynamic finders to search for null values, you need to use the findBySomethingIsNull version instead. Try
def user = (session.email ? User.findByEmail(session.email)
: User.findByEmailIsNull())
Note that even if User.findByEmail(null) worked correctly every time, it would not necessarily give you the correct results on all databases as a findBySomething(null) would translate to
WHERE something = null
in the underlying SQL query, and according to the SQL spec null is not equal to anything else (not even to null). You have to use something is null in SQL to match null values, which is what findBySomethingIsNull() translates to.
You could write a static utility method in the User class to gather this check into one place
public static User byOptEmail(val) {
if(val == null) {
return User.findByEmailIsNull()
}
User.findByEmail(val)
}
and then use User.byOptEmail(session.email) in your controllers.

Jeff Brown from grails nabble forum has identified my problem. It's a GORM bug. see jira
More info on this thread
This jira too

I tried with debugger and it looks it should be working, as you write. Maybe the groovy itself is a little bit confused here, try to help it this way:
User.findByEmail( session['email'] )

Related

Unapprovable RejectedAccessException when using Tuple in Jenkinsfile

I tried to use Tuple in a Jenkinsfile.
The line I wrote is def tupleTest = new Tuple('test', 'test2').
However, Jenkins did not accept this line and keep writing the following error to the console output:
No such constructor found: new groovy.lang.Tuple java.lang.String java.lang.String. Administrators can decide whether to approve or reject this signature.
...
org.jenkinsci.plugins.scriptsecurity.sandbox.RejectedAccessException: No such constructor found: new groovy.lang.Tuple java.lang.Integer java.lang.String
...
When I visited the "Script Approval" configuration I could not see any scripts that pend approval.
Following this link, I tried to install and enable the "Permissive Security" plugin, but it did not help either - The error was the same.
I even tried to manually add the problematic signature to the scriptApproval.xml file. After I added it, I was able to see it in the list of approved signatures, but the error still remained.
Is there something I am doing wrong?
I had the same issue trying to use tuple on jenkins so I found out that I can simply use a list literal instead:
def tuple = ["test1", "test2"]
which is equivalent to
def (a, b) = ["test1", "test2"]
So now, instead of returning a tuple, I am returning a list in my method
def myMethod(...) {
...
return ["test 1", "test 2"]
}
...
def (a, b) = myMethod(...)
This is more or less a problem caused by groovy.lang.Tuple constructor + Jenkins sandbox Groovy mode. If you take a look at the constructor of this class you will see something like this:
package groovy.lang;
import java.util.AbstractList;
import java.util.List;
public class Tuple extends AbstractList {
private final Object[] contents;
private int hashCode;
public Tuple(Object[] contents) {
if (contents == null) throw new NullPointerException();
this.contents = contents;
}
//....
}
Groovy sandbox mode (enabled by default for all Jenkins pipelines) ensures that every invocation passes script approval check. It's not foolproof, and when it sees new Tuple('a','b') it thinks that the user is looking for a constructor that matches exactly two parameters of type String. And because such constructor does not exists, it throws this exception. However, there are two simple workarounds to this problem.
Use groovy.lang.Tuple2 instead
If your tuple is a pair, then use groovy.lang.Tuple2 instead. The good news about this class is that it provides a constructor that supports two generic types, so it will work in your case.
Use exact Object[] constructor
Alternatively, you can use the exact constructor, e.g
def tuple = new Tuple(["test","test2"] as Object[])
Both options require script approval before you can use them (however, in this case both constructors appear in the in-process script approval page).

closure verification override default mocking

I have a method looks like this:
public void save(DbSession session,Wrappe wrapper,Wrappe wrappe){
//...other logic
//save wrapper
wrapper=(Wrapper)session.save(wrapper)
//set wrapper's id into wrappee
wrappee.setWrapperId(wrapper.getId());
//save wrappee
session.save(wrappee);
}
and test code looks like this:
given:
session.save(_) >> wrapperWithGeneratedId
when:
obj.save(session,wrapper,wrappee)
then:"wrapper got saved"
1*session.save(_) >> {Wrapper save ->
diffs(wrapper,saved)==null
}
and:"wrappee"
1*session.save(_) >> {Wrappe saved ->
diffs(wrappee,saved)==null
}
These test code will give an exception:
java.lang.ClassCastException: java.lang.Boolean cannot be cast to com.company.model.Wrapper
If commented verification closure in "then" section,test will pass,so I guess this section
1*session.save(_) >> {Wrapper save ->
diffs(wrapper,saved)==null
}
overrode this mocking:
session.save(_) >> wrapperWithGeneratedId
Is any way do both correctly?
1st. 'and' is syntactic sugar. It's just a way to visually separate code within the same block. Your last two mocks are effectively the same (although since you're testing behaviorally it will still verify that save is called twice.)
2nd. Assuming you want to verify thatdiffs(wrapper,saved)==null, that won't currently happen because it's not a 'base level' evaluation. Anything within then/where/closures/etc needs to be prepended with 'assert ' if you want to evaluate it.
3rd. A then block is scoped to its when block and can override existing mocks; your assumption that your mock was being overwritten is correct.
4th. Is there any reason you don't just include your return value alongside your evaluation?
2 * session.save(_) >> {Wrapper save ->
diffs(wrapper,saved)==null
return wrapperWithGeneratedId
}
5th. Your error is due to your mock returning a boolean (your assertion logic) which Groovy then tries (and fails) to parse into a Wrapper. My assumption for why this is happening is that .save() has a return type of Wrapper. To fix that you will either need to create a boolean constructor for Wrapper, or change your mock to return something Groovy can turn into a Wrapper (how-to in point 4)
Official Stub/Mock/Spy documentation (quite good, worth a read)

Breeze: Cannot read property 'xxx' of null?

I understand there are a few similar questions (e.g. here), but they all seem to be in different context. This is what I see in my chrome console:
Unhandled rejection reasons (should be empty):
["TypeError: Cannot read property 'compound' of null…://localhost:1476/Scripts/breeze.debug.js:234:15)", joinBy: function, equals: function, indexByKey: function, getByKey: function, sortOn: function]
I could see this error in my debugger at failed(error):
return manager.executeQuery(query).then(succeeded).fail(failed);
function failed(error) {
logger.logError(error);
}
For a specific object, it happens most of time, but no always (maybe one out of 10 is okay). The query from server returns without exception. As I figured, it seems to be related to the query with a specific include of table. However, in fact, in this case, the included table doesn't have any related entry yet (if there is an entry, it doesn't seem to have any problem). Any idea?
Okay, I accidentally found out what has caused this error. It is metadatastore post-construction initializer like
manager.metadataStore.registerEntityTypeCtor("Result", Result, initialize);
// constructor
function Result() {
}
// post-construction initializer
function initialize(result) {
result.cmpName = result.cs.compound.name;
}
where result.cs could be null sometimes.
Too bad the error message didn't provide any clue.

Is None less evil than null?

In F# its a big deal that they do not have null values and do not want to support it. Still the programmer has to make cases for None similar to C# programmers having to check != null.
Is None really less evil than null?
The problem with null is that you have the possibility to use it almost everywhere, i.e. introduce invalid states where this is neither intended nor makes sense.
Having an 'a option is always an explicit thing. You state that an operation can either produce Some meaningful value or None, which the compiler can enforce to be checked and processed correctly.
By discouraging null in favor of an 'a option-type, you basically have the guarantee that any value in your program is somehow meaningful. If some code is designed to work with these values, you cannot simply pass invalid ones, and if there is a function of option-type, you will have to cover all possibilities.
Of course it is less evil!
If you don't check against None, then it most cases you'll have a type error in your application, meaning that it won't compile, therefore it cannot crash with a NullReferenceException (since None translates to null).
For example:
let myObject : option<_> = getObjectToUse() // you get a Some<'T>, added explicit typing for clarity
match myObject with
| Some o -> o.DoSomething()
| None -> ... // you have to explicitly handle this case
It is still possible to achieve C#-like behavior, but it is less intuitive, as you have to explicitly say "ignore that this can be None":
let o = myObject.Value // throws NullReferenceException if myObject = None
In C#, you're not forced to consider the case of your variable being null, so it is possible that you simply forget to make a check. Same example as above:
var myObject = GetObjectToUse(); // you get back a nullable type
myObject.DoSomething() // no type error, but a runtime error
Edit: Stephen Swensen is absolutely right, my example code had some flaws, was writing it in a hurry. Fixed. Thank you!
Let's say I show you a function definition like this:
val getPersonByName : (name : string) -> Person
What do you think happens when you pass in a name of a person who doesn't exist in the data store?
Does the function throw a NotFound exception?
Does it return null?
Does it create the person if they don't exist?
Short of reading the code (if you have access to it), reading the documentation (if someone was kindly enough to write it), or just calling the function, you have no way of knowing. And that's basically the problem with null values: they look and act just like non-null values, at least until runtime.
Now let's say you have a function with this signature instead:
val getPersonByName : (name : string) -> option<Person>
This definition makes it very explicit what happens: you'll either get a person back or you won't, and this sort of information is communicated in the function's data type. Usually, you have a better guarantee of handling both cases of a option type than a potentially null value.
I'd say option types are much more benevolent than nulls.
In F# its a big deal that they do not have null values and do not want to support it. Still the programmer has to make cases for None similar to C# programmers having to check != null.
Is None really less evil than null?
Whereas null introduces potential sources of run-time error (NullRefereceException) every time you dereference an object in C#, None forces you to make the sources of run-time error explicit in F#.
For example, invoking GetHashCode on a given object causes C# to silently inject a source of run-time error:
class Foo {
int m;
Foo(int n) { m=n; }
int Hash() { return m; }
static int hash(Foo o) { return o.Hash(); }
};
In contrast, the equivalent code in F# is expected to be null free:
type Foo =
{ m: int }
member foo.Hash() = foo.m
let hash (o: Foo) = o.Hash()
If you really wanted an optional value in F# then you would use the option type and you must handle it explicitly or the compiler will give a warning or error:
let maybeHash (o: Foo option) =
match o with
| None -> 0
| Some o -> o.Hash()
You can still get NullReferenceException in F# by circumventing the type system (which is required for interop):
> hash (box null |> unbox);;
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.FSharp.Core.LanguagePrimitives.IntrinsicFunctions.UnboxGeneric[T](Object source)
at <StartupCode$FSI_0021>.$FSI_0021.main#()
Stopped due to error

Grails: No signature of method findAll() is applicable for argument types: String, ArrayList

I'm new to grails and receive the following error:
No signature of method: Something.findAll() is applicable for argument types: (java.lang.String, java.util.ArrayList) values: [from Something AS s WHERE s.some_number LIKE ?, [%asdf%]]"
The error occurs when I run test-app. It occurs in the following place:
SomethingVO[] findBySomeNumber(String searchString) {
searchString = "%"+searchString+"%"
return Something.findAll("from Something AS s WHERE s.some_number LIKE ?",[searchString]).collect {
new SomethingVO(it);
}
}
The class Something is a domain object:
package some.project.domain
class Something{
static belongsTo = [product:Product, productVersion:ProductVersion]
Long id
String name
String someNumber
static constraints = {
product (nullable:true)
productVersion (nullable:true)
}
}
Where is the mistake?
(I use Grails 1.2.4)
findAll is not mocked during unit testing and that's why your code isn't working. You need to manually add a mock for the call before running your test (mockFor could help you with that). This applies if your use HQL or Criterias (which I would recommend over pure HQL).
Alternatively it's possible that you could solve your problems using dynamic finders. Dynamic finders and the other dynamic ORM methods (save, get, count, ..) are in most(?) cases mocked when you call mockDomain(Something) in your unit test. They are also generally easier to use than HQL (imho).
Update:
Thanks to Fletch for pointing out that not all dynamic finders are mocked. An example of a dynamic finder that won't be mocked is this: Something.findAllWhereSomeNumberInList([1, 2, 3]).
The HQL you use in your code could be rewritten like this using dynamic finders:
Something.findBySomeNumberLike(searchString)
Xlson's answer is correct, however there is an alternative "cutting edge" solution you can try, which is currently in testing status. See http://grails.1312388.n4.nabble.com/New-approach-to-mocking-domain-classes-in-Grails-unit-tests-td2529895.html

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