Report validation error for duplicate action names

[poutsma]

This PR ensures that actions names only occur once, and reports a validation error otherwise.

Closes: gh-1304

[igordayen]

minor comment to consider in future. looks good

[igordayen]

at some point for documentation purposes perhaps collect all error codes / maintain enum for ValidationError.code:

./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/GoapPathToCompletionValidator.kt:import com.embabel.common.core.validation.ValidationError
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/GoapPathToCompletionValidator.kt:        val errors = mutableListOf<ValidationError>()
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/GoapPathToCompletionValidator.kt:    ): ValidationError =
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/GoapPathToCompletionValidator.kt:        ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:import com.embabel.common.core.validation.ValidationError
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:                val error = ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:        val errors = mutableListOf<ValidationError>()
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:                ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:                ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:                    ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/spi/validation/DefaultAgentStructureValidator.kt:                    ValidationError(
./embabel-agent-api/src/main/kotlin/com/embabel/agent/core/hitl/FormBindingRequest.kt:interface ValidationError
./embabel-agent-api/src/main/kotlin/com/embabel/agent/core/hitl/FormBindingRequest.kt:    val validationErrors: List<ValidationError> = emptyList(),
./embabel-agent-api/src/main/kotlin/com/embabel/common/core/validation/ValidationResult.kt:    val errors: List<ValidationError>,
./embabel-agent-api/src/main/kotlin/com/embabel/common/core/validation/ValidationError.kt:data class ValidationError  @JvmOverloads constructor(

[alexheifetz]

Very nice fix — groupBy { it.name }.filter { it.value.size > 1 } is the right idiom and the validator is the right layer.

Two minor things:

• Agreeing with @igordayen on typed error codes — the raw string in the test assertion is a silent typo risk.
• The error message could include the declaring class of each duplicate so the developer knows where to look, not just that a collision exists.

[poutsma]

• Agreeing with @igordayen on typed error codes — the raw string in the test assertion is a silent typo risk.

Sounds good, I will create a follow-up issue for that.

• The error message could include the declaring class of each duplicate so the developer knows where to look, not just that a collision exists.

The action name is used in the message, and will be the fully qualified method name when using annotations. For instance, for the unit test it's com.embabel.agent.api.annotation.support.AgentWithDuplicateActionNames.respond.

[poutsma]

I have created #1533 to collect all validation error codes.