[FEATURE REQ] | Runtime error advice when unique key annotation is not properly initialized.

[rishi2758]

Is your feature request related to a problem? Please describe.
While working with cosmos dB java sdk, I faced an issue where I was trying to setup, Unique Key using @CosmosUniqueKey and @CosmosUniqueKeyPolicy annotations, but struggled for quite a while later i saw while searching over GitHub that in Readme.md examples does exists.

Describe the solution you'd like
I was thinking to improve this annotation configuration by raising the exception if user has incorrectly configured the annotations.
or may be ensure the type safety by specifying what is expected as an argument in @CosmosUniqueKeyPolicy.

Describe alternatives you've considered
None, it's just that if we can improve this i think others can benefit such that if they incorrectly configured the annotations, they might know at runtime or compile time.
As i was clueless why this was not working when i configured @CosmosUniqueKey and @CosmosUniqueKeyPolicy separately over the entity class.

Additional context
We can make changes here, if you want i can quickly raise the PR for this change

azure-sdk-for-java/sdk/spring/azure-spring-data-cosmos/src/main/java/com/azure/spring/data/cosmos/repository/support/CosmosEntityInformation.java

Line 352 in 7daf45a

private static UniqueKeyPolicy getUniqueKeyPolicy(Class<?> domainType) {

Information Checklist
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[Netyyyy]

@kushagraThapar please help take a look, thanks.

[kushagraThapar]

@rishi2758 - what is the issue that you are facing? I would like to get some more information here, thanks!

[rishi2758]

@kushagraThapar Thanks for taking out time to respond,

While I was configuring the @ComsosUniqueKeyPolicy annotation provided, it took me a bit amount of time, as I was trying different combinations to configure it.
I was thinking why not add the compile time restriction at this annotation level so that users can get to know what is excepted as a argument like @ComsosUniqueKeyPolicy was expecting unique key to be provided using @CosmoUniqueKey annotation
but I was trying to specify using the plain path.

also the inconvenience is caused by more from a non-availability of proper documentation but i feel if that can also be done at annotation level it would be an added advantage.

if you feel is this something that can be taken up, i would be happy to raise quick PR for this change.

[kushagraThapar]

@rishi2758 - thanks for explaining more, so this looks more like documentation + samples change. A PR from your side will be really appreciated, thanks!

[rishi2758]

apologies if i might have not been clear earlier

documentation provided in the repositories are okay, it's just that we should have them somewhere in the official azure like here (https://learn.microsoft.com/en-us/azure/cosmos-db/how-to-define-unique-keys?tabs=dotnetv2#use-the-java-sdk)

also
i wanted to raise one more concern that if we try to annotate a class directly with @CosmosUniqueKey annotation, it doesn't reports any error instead just ignores the annotation continues without creation of the unique keys.

i was wondering if we can introduce a feature where if @CosmosUniqueKey annotation if directly used without @CosmosUniqueKeyPolicy annotation, it will report an error at application startup ? and also may be point out to the users to our official docs , hinting them to configure it correctly,
Let me know what are your thoughts ?

@CosmosUniqueKey(paths = "/name") public class Example { private String name }
whereas correct way is
@CosmosUniqueKeyPolicy(uniqueKeys = { @CosmosUniqueKey(paths = "/name") } ) public class Example { private String name }
In the first example ignores the annotation and proceeds with further execution without the creation of unique keys.

[rishi2758]

apologies if i might have not been clear earlier

documentation provided in the repositories are okay, it's just that we should have them somewhere in the official azure like here (https://learn.microsoft.com/en-us/azure/cosmos-db/how-to-define-unique-keys?tabs=dotnetv2#use-the-java-sdk)

also i wanted to raise one more concern that if we try to annotate a class directly with @CosmosUniqueKey annotation, it doesn't reports any error instead just ignores the annotation continues without creation of the unique keys.

i was wondering if we can introduce a feature where if @CosmosUniqueKey annotation if directly used without @CosmosUniqueKeyPolicy annotation, it will report an error at application startup ? and also may be point out to the users to our official docs , hinting them to configure it correctly, Let me know what are your thoughts ?

@CosmosUniqueKey(paths = "/name") public class Example { private String name } whereas correct way is @CosmosUniqueKeyPolicy(uniqueKeys = { @CosmosUniqueKey(paths = "/name") } ) public class Example { private String name } In the first example ignores the annotation and proceeds with further execution without the creation of unique keys.

@kushagraThapar

[wallysoncarvalho]

@rishi2758 , do we need any configuration for this to work ? I'm having the same issue with both modes of indexing.

Spring boot: 3.1.1
Java: 17
Dependency: spring-cloud-azure-starter-data-cosmos:5.3.0

Kotlin Class example:

@CosmosUniqueKeyPolicy(
    uniqueKeys = [
        CosmosUniqueKey(paths = ["/prop1"])
    ]
)
@Container(containerName = "outraClasse")
class OutraClasse(
    @Id
    @PartitionKey
    val prop2: Int,
    val prop1: String,
)

I'm testing this using the Emulator. I tried with "spring data" created container and the index wasnt created. Then I tried manually through the Emulator's interface and it worked.

[rishi2758]

I'm testing this using the Emulator. I tried with "spring data" created container and the index wasn't created. Then I tried manually through the Emulator's interface and it worked.

for configuring the indices you need to use 👉 @CosmosIndexingPolicy(includePaths = {"/prop1"})

more documentation can be found here

@wallysoncarvalho