Config: Pattern converter error when Pattern used as key in Map to Nested Group

[rudiger3d]

Describe the bug

If I have the following code:

@ConfigMapping(prefix = "provider.tryg")
public interface TrygConfiguration {
    Map<Pattern, String> infoMapping();
}

and application.properties

provider.tryg.info-mapping.Campervan\ \\d=CAMPERVAN

and change the infoMapping() Map to

@ConfigMapping(prefix = "provider.tryg")
public interface TrygConfiguration {
    Map<Pattern, NameLimit> infoMapping();

    interface NameLimit {
        String name();
        int limit();
    }
}

provider.tryg.info-mapping.Campervan\ \\d.name=CAMPERVAN
provider.tryg.info-mapping.Campervan\ \\d.limit=7000

Expected behavior

Then if I iterate the TrygConfiguration.infoMapping() entrySet(), i.e.

    Map.Entry<Pattern, ...>
    entry.getKey().matcher("Campervan 6").matches();

I'd expect entry.getKey().matcher("Campervan 6").matches() to return true in both cases.

Actual behavior

However in the second case, it returns false, because the internal pattern of the converted java.util.regex.Pattern is "Campervan d" and not "Campervan \\d".

I know it is somewhat weird to use Pattern as a key in a Map, as you may only retrieve it via iteration, but it made the corresponding configuration in the "application.properties" easier to write so that's why :)

How to Reproduce?

No response

Output of uname -a or ver

Darwin CO-MBP-C02YL4N9LVCF-DK 23.6.0 Darwin Kernel Version 23.6.0: Mon Jul 29 21:13:00 PDT 2024; root:xnu-10063.141.2~1/RELEASE_X86_64 x86_64

Output of java -version

openjdk version "21.0.5" 2024-10-15 LTS OpenJDK Runtime Environment Temurin-21.0.5+11 (build 21.0.5+11-LTS) OpenJDK 64-Bit Server VM Temurin-21.0.5+11 (build 21.0.5+11-LTS, mixed mode)

Quarkus version or git rev

3.17.0

Build tool (ie. output of mvnw --version or gradlew --version)

No response

Additional information

No response

[quarkus-bot]

/cc @radcortez (config)

[radcortez]

Our own key parser uses \ as an escape sequence, meaning that if you want to have a key with a Pattern with a proper escape sequence, you need to use Campervan\ \\\\d.

[rudiger3d]

Our own key parser uses \ as an escape sequence, meaning that if you want to have a key with a Pattern with a proper escape sequence, you need to use `Campervan\ \d.

I'm not totally sure I follow: In both cases above I have used \ as an escape sequence for the key:

provider.tryg.info-mapping.Campervan\ \\d=CAMPERVAN

and

provider.tryg.info-mapping.Campervan\ \\d.name=CAMPERVAN.

The first case, the Pattern is parsed correctly, but second where the value of the map is a nested group, it does not.

I can provide a reproducer, but if this is only supported by accident then I guess it won't really matter...

[rudiger3d]

Now I understand. An extra \ (java-style) works:

provider.tryg.info-mapping.Campervan\ \\\\d.name=CAMPERVAN.

Sorry for the noise. Btw, quarkus-config/smallrye config is great, and we use it extensively in our services.

[radcortez]

Yes, I'm sorry. I noticed that my comment was misleading. I did type \\\\d, but I missed the final code block end element, and it got displayed as \\d only.

Thank you very much for your feedback. Feel free to provide ideas or improvements :)