Support interface entity types with EntityDecorator

[Copilot]

Implementation: Interface Entity Support in Repositories ✅

Problem: Nitrite could not use interface types as entity types in repositories because the Reflector.getField() method only looked for declared fields, which don't exist on interfaces.

Solution: Enhanced the reflection infrastructure to detect and handle interface properties defined as getter methods.

Changes Made:

• Analyze the current Reflector class to understand all usages
• Create test case that reproduces the issue with interface entities
• Modify Reflector.getField() to support interface properties via getter methods
• Modify Reflector.getEmbeddedField() to support interface properties
• Modify Reflector.getAllFields() to support interface properties
• Create InterfacePropertyHolder helper class to store synthetic field metadata
• Create FieldAccessHelper to handle get/set on interface property fields
• Update EntityDecoratorScanner to use property metadata for validation
• Update AnnotationScanner to use property metadata for validation
• Update RepositoryOperations to use FieldAccessHelper for field access
• Fix Android compatibility issues
• Add comprehensive tests for interface entity support
• Run full test suite to ensure no regressions (1628 tests pass)
• Address code review feedback
  • Reduced NPath complexity in isCompatiblePrimitive
  • Upgraded Android API from 24 to 26
  • Replaced setAccessible with MethodHandles for improved security
  • Added tests with multiple implementations (Dog, Cat, Bird)
  • Added edge case tests

Technical Implementation:

1. Interface Property Detection: Modified Reflector to detect getter methods on interfaces and create synthetic Field representations
2. Property Metadata Storage: Created InterfacePropertyHolder to store mapping between synthetic fields and actual property information
3. Field Access Abstraction: Created FieldAccessHelper that uses MethodHandles API for secure field/method access
4. Validation Updates: Updated scanners to use property metadata for correct type and name information during validation

Android API Upgrade:

• Previous: Android API 24 (Android 7.0)
• Current: Android API 26 (Android 8)
• Benefits:
  • Access to MethodHandles API (available since Android API 26)
  • Improved security with unreflectGetter/unreflectSetter instead of setAccessible
  • Better performance with MethodHandle.invokeWithArguments
  • Modern reflection approach aligned with current Android development

Code Quality Improvements:

• Simplified isCompatiblePrimitive using single return statement (reduced NPath complexity from 256 to acceptable levels)
• Replaced setAccessible with MethodHandles for field and method access
• Uses unreflectGetter, unreflectSetter, and unreflect with invokeWithArguments
• Added 5 additional comprehensive tests covering multiple implementations and edge cases

Test Coverage:

• 8 tests in InterfaceEntityTest covering:
  • Basic interface entity validation
  • Index creation for interface properties
  • Field access on multiple implementations (Dog, Cat, Bird)
  • Edge cases (null/empty property names)
  • Boolean properties with 'is' prefix
  • Multiple classes with same interface
• All 1628 tests pass with Android API 26 compatibility

Documentation Updates:

• Updated README.md to reflect Android API 26 compatibility
• Updated .github/copilot-instructions.md to reflect Android API 26+ requirement
• Updated pom.xml with Android API 26 signature configuration

<issue_title>Migration from Mongo: repositories of interface entities</issue_title>

• Fixes Migration from Mongo: repositories of interface entities #1169

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Migration from Mongo: repositories of interface entities</issue_title>
<issue_description>Hi,

We are trying to migrate the Mongo repository implementation of our desktop application to a more lightweight alternative. We think Nitrite could be a worthy alternative but we're struggling with the repository model. We are using version 4.3.1.

The domain is written in Kotlin and highly generic. The base type is an interface holding an id. (Types are renamed for obfuscation purposes, we're not building a zoo application ;p)

interface Animal {
   val id: AnimalUrn
   ...
}

interface LiveAnimal : Animal {   
   override val id: LiveAnimalUrn
   ...
}

data class LiveElephant(
   override val id: LiveAnimalUrn,
   var name: String,
   ...
) : LiveAnimal

We need to be able to store implementations of LiveAnimal in a single repository. We cannot annotate the domain (it is owned by another business unit) so we need to reside to an EntityDecorator (our application is in Java):

public class LiveDeviceDecorator implements EntityDecorator<LiveDevice> {
   @Override
   public Class<LiveDevice> getEntityType() {
      return LiveDevice.class;
   }

   @Override
   public EntityId getIdField() {
      return new EntityId("id");
   }

   ...
}

When starting the server, this gives a ValidationException: No such field 'id' for type x.y.z.LiveAnimal on Reflector.getField(Reflector.java:127).

I read in #54 that repositories for interface entities are currently not supported. However with Mongo, we were able to use the LiveDevice abstraction without any problem. Reflector looks for a declared field which of course doesn't exist on the interface.

Are there any plans in the future to support this use case, i.e. also checking the declared accessors on the interface?</issue_description>

<agent_instructions>Analyze the issue and do a feasibility study first. If it is feasible, make necessary code changes, verify all test suites pass. If any test fails, work on it to fix the test failure.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Migration from Mongo: repositories of interface entities #1169

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[Copilot]

Pull Request Overview

This PR adds support for interface entity types in Nitrite repositories by enhancing the reflection infrastructure to handle interface properties defined as getter methods. Previously, using interface types with EntityDecorator failed because Reflector.getField() only looked for declared fields, which don't exist on interfaces. The solution creates synthetic field representations for interface properties and uses MethodHandles for secure field access.

Key changes:

• Enhanced reflection to detect and handle interface properties via getter methods
• Upgraded Android API compatibility from 24 to 26 to support MethodHandles
• Added comprehensive test coverage for interface entity support

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
pom.xml	Updated Android API level from 24 to 26 for MethodHandles support
InterfaceEntityTest.java	Added comprehensive tests for interface entity support with multiple implementations
RepositoryOperations.java	Updated to use FieldAccessHelper and InterfacePropertyHolder for field access
Reflector.java	Enhanced to detect interface properties from getter methods and create synthetic fields
InterfacePropertyHolder.java	New class storing metadata mapping between synthetic fields and interface properties
FieldAccessHelper.java	New helper class handling field access using MethodHandles API for security
EntityDecoratorScanner.java	Updated validators to use property metadata for correct type/name information
AnnotationScanner.java	Updated validators to use property metadata for correct type/name information
README.md	Updated Android API compatibility documentation from 24 to 26
.github/copilot-instructions.md	Updated Android API compatibility documentation from 24 to 26