Duplicate key error thrown when extending Faker class

[jsolferreira]

Describe the bug
If a class that extends the Faker class has two methods returing the same type, calling one method of the Faker class throws the following error:

Exception in thread "main" java.lang.IllegalStateException: Duplicate key String (attempted merging values public java.lang.Long org.example.BaseFaker.anotherMethodReturningString() and public java.lang.Long org.example.BaseFaker.oneMethodReturningString())
	at java.base/java.util.stream.Collectors.duplicateKeyException(Collectors.java:135)
	at java.base/java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(Collectors.java:182)
	at java.base/java.util.stream.ReduceOps$3ReducingSink.accept(ReduceOps.java:169)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:1024)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
	at net.datafaker.providers.base.ObjectMethods.scanMethodsByReturnType(ObjectMethods.java:26)
	at java.base/java.util.Map.computeIfAbsent(Map.java:1066)
	at net.datafaker.providers.base.ObjectMethods.getMethodByReturnType(ObjectMethods.java:44)
	at net.datafaker.providers.base.ObjectMethods.executeMethodByReturnType(ObjectMethods.java:50)
	at net.datafaker.providers.base.ProviderRegistration.getProvider(ProviderRegistration.java:20)

To Reproduce

BaseFaker class:

import net.datafaker.Faker;

public class BaseFaker extends Faker {

    public String oneMethodReturningString() {

        return this.name().fullName();
    }

    public String anotherMethodReturningString() {

        return this.name().fullName();
    }
}

The error is thrown when calling oneMethodReturningString()

public class Main {

    public static void main(String[] args) {

        BaseFaker baseFaker = new BaseFaker();

        baseFaker.oneMethodReturningString();
    }
}

Expected behavior
The error should not be thrown

Versions:

• OS: Windows
• JDK: Java 21
• Faker Version [e.g. 2.4.0]

Additional context
The error starts to happen after version 2.3.0. With version 2.2.2 the code provided works well

[bodiam]

Hi @jsolferreira , I think this may have been introduced as part of #1271.

@asolntsev , is this something you could have a look at?

[asolntsev]

@jsolferreira thank you for the precise description and steps to reproduce. It helps to quickly fix the problem!

Should be fixed by this PR: #1369

[bodiam]

@jsolferreira could you please give the snapshot release a try? If it works, I'll publish a new release.

[jsolferreira]

@bodiam @asolntsev Just tested the same code example and it worked with version 2.4.1-SNAPSHOT

Thanks for the quick fix!