Use specific interfaces of EntityState types

Also:
 * Improve common test fixtures.

Author: alexander-yevsyukov

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/EntityPluginTestSetup.kt

@@ -32,6 +32,7 @@ import io.spine.tools.core.jvm.gradle.settings.EntitySettings
 import io.spine.tools.core.jvm.settings.Entities
 import io.spine.tools.psi.java.method
 import java.nio.file.Path
+import kotlin.io.path.Path
 import org.junit.jupiter.api.assertDoesNotThrow
 import org.junit.jupiter.api.assertThrows
 
@@ -45,10 +46,18 @@ abstract class EntityPluginTestSetup : PluginTestSetup<Entities>(
 ) {
 
     companion object {
+
         /**
          * The path to the Java file generated for the `Department` entity state.
          */
-        const val DEPARTMENT_JAVA = "io/spine/tools/core/jvm/entity/given/Department.java"
+        val departmentJava = "Department".java
+
+        /**
+         * Obtains a path to a Java source file for the proto type with this name.
+         */
+        val String.java get() = Path(
+            "io/spine/tools/core/jvm/entity/given/$this.java"
+        )
     }
 
     override fun createSettings(projectDir: Path): Entities {

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/ImplementEntityStateSpec.kt

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2025, TeamDev. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.tools.core.jvm.entity
+
+import io.kotest.matchers.string.shouldContain
+import io.spine.base.AggregateState
+import io.spine.base.EntityState
+import io.spine.base.ProcessManagerState
+import io.spine.base.ProjectionState
+import io.spine.tools.code.Java
+import io.spine.tools.compiler.render.SourceFile
+import io.spine.tools.core.jvm.entity.EntityPluginTestSetup.Companion.java
+import io.spine.tools.java.reference
+import java.nio.file.Path
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.io.TempDir
+
+@DisplayName("`ImplementEntityState` action should")
+class ImplementEntityStateSpec {
+
+    private lateinit var sourceFile: SourceFile<Java>
+
+    companion object : EntityPluginTestSetup() {
+
+        @BeforeAll
+        @JvmStatic
+        fun setup(@TempDir projectDir: Path) {
+            runPipeline(projectDir)
+        }
+    }
+
+    @Test
+    fun `use 'AggregateState' interface for 'AGGREGATE' kind`() {
+        sourceFile = file("Employee".java)
+        sourceFile.code().shouldContain(AggregateState::class.java.reference)
+    }
+
+    @Test
+    fun `use 'ProjectionState' interface for 'PROJECTION' kind`() {
+        sourceFile = file("Organization".java)
+        sourceFile.code().shouldContain(ProjectionState::class.java.reference)
+    }
+
+    @Test
+    fun `use 'ProcessManagerState' interface for 'PROCESS_MANAGER' kind`() {
+        sourceFile = file("Transition".java)
+        sourceFile.code().shouldContain(ProcessManagerState::class.java.reference)
+    }
+
+    @Test
+    fun `use 'EntityState' interface for 'ENTITY' kind`() {
+        sourceFile = file("Blob".java)
+        sourceFile.code().shouldContain(EntityState::class.java.reference)
+    }
+}

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/column/AddColumnClassSpec.kt

@@ -40,7 +40,6 @@ import io.spine.tools.core.jvm.entity.assertHasMethod
 import io.spine.tools.java.reference
 import io.spine.tools.psi.java.locate
 import java.nio.file.Path
-import kotlin.io.path.Path
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
@@ -60,7 +59,7 @@ internal class AddColumnClassSpec {
         @JvmStatic
         fun setup(@TempDir projectDir: Path) {
             runPipeline(projectDir)
-            val sourceFile = file(Path(DEPARTMENT_JAVA))
+            val sourceFile = file(departmentJava)
             entityStateCode = sourceFile.code()
             psiFile = sourceFile.psi() as PsiJavaFile
         }

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/field/AddFieldClassSpec.kt

@@ -59,7 +59,7 @@ internal class AddFieldClassSpec {
         @JvmStatic
         fun setup(@TempDir projectDir: Path) {
             runPipeline(projectDir)
-            val sourceFile = file(Path(DEPARTMENT_JAVA))
+            val sourceFile = file(departmentJava)
             entityStateCode = sourceFile.code()
             psiFile = sourceFile.psi() as PsiJavaFile
         }

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/query/QueryBuilderClassSpec.kt

@@ -43,7 +43,6 @@ import io.spine.tools.psi.java.isPublic
 import io.spine.tools.psi.java.method
 import io.spine.tools.psi.java.topLevelClass
 import java.nio.file.Path
-import kotlin.io.path.Path
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
@@ -61,7 +60,7 @@ internal class QueryBuilderClassSpec {
         @JvmStatic
         fun setup(@TempDir projectDir: Path) {
             runPipeline(projectDir)
-            val sourceFile = file(Path(DEPARTMENT_JAVA))
+            val sourceFile = file(departmentJava)
             val psiFile = sourceFile.psi() as PsiJavaFile
             entityStateClass = psiFile.topLevelClass
         }

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/query/QueryClassSpec.kt

@@ -36,7 +36,6 @@ import io.spine.tools.core.jvm.entity.EntityPluginTestSetup
 import io.spine.tools.kotlin.reference
 import io.spine.tools.psi.java.topLevelClass
 import java.nio.file.Path
-import kotlin.io.path.Path
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
@@ -53,7 +52,7 @@ internal class QueryClassSpec {
         @JvmStatic
         fun setup(@TempDir projectDir: Path) {
             runPipeline(projectDir)
-            val sourceFile = file(Path(DEPARTMENT_JAVA))
+            val sourceFile = file(departmentJava)
             val psiFile = sourceFile.psi() as PsiJavaFile
             entityStateClass = psiFile.topLevelClass
         }

entity-tests/src/test/kotlin/io/spine/tools/core/jvm/entity/query/QueryMethodSpec.kt

@@ -35,7 +35,6 @@ import io.spine.tools.core.jvm.entity.EntityPluginTestSetup
 import io.spine.tools.psi.java.method
 import io.spine.tools.psi.java.topLevelClass
 import java.nio.file.Path
-import kotlin.io.path.Path
 import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.DisplayName
 import org.junit.jupiter.api.Test
@@ -53,7 +52,7 @@ internal class QueryMethodSpec {
         @JvmStatic
         fun setup(@TempDir projectDir: Path) {
             runPipeline(projectDir)
-            val sourceFile = file(Path(DEPARTMENT_JAVA))
+            val sourceFile = file(departmentJava)
             psiFile = sourceFile.psi() as PsiJavaFile
         }
     }

entity-tests/src/testFixtures/proto/given/entities/organization.proto

@@ -66,3 +66,15 @@ message Organization {
     string name = 2 [(required) = true, (column) = true];
     repeated Department department = 3 [(required) = true];
 }
+
+message Transition {
+    option (entity).kind = PROCESS_MANAGER;
+    EmployeeId id = 1;
+    DepartmentKey from = 2 [(required) = true];
+    DepartmentKey to = 3 [(required) = true];
+}
+
+message Blob {
+    option (entity).kind = ENTITY;
+    int32 id = 1;
+}

entity/src/main/kotlin/io/spine/tools/core/jvm/entity/ImplementEntityState.kt

@@ -27,7 +27,15 @@
 package io.spine.tools.core.jvm.entity
 
 import com.google.protobuf.Empty
+import io.spine.base.AggregateState
 import io.spine.base.EntityState
+import io.spine.base.ProcessManagerState
+import io.spine.base.ProjectionState
+import io.spine.option.EntityOption
+import io.spine.option.EntityOption.Kind.AGGREGATE
+import io.spine.option.EntityOption.Kind.ENTITY
+import io.spine.option.EntityOption.Kind.PROCESS_MANAGER
+import io.spine.option.EntityOption.Kind.PROJECTION
 import io.spine.tools.compiler.ast.MessageType
 import io.spine.tools.compiler.ast.firstField
 import io.spine.tools.compiler.context.CodegenContext
@@ -37,11 +45,19 @@ import io.spine.tools.compiler.jvm.render.ImplementInterface
 import io.spine.tools.compiler.jvm.render.superInterface
 import io.spine.tools.compiler.render.SourceFile
 import io.spine.tools.code.Java
+import io.spine.tools.compiler.ast.option
+import io.spine.tools.compiler.ast.unpack
 import io.spine.tools.java.reference
+import kotlin.reflect.KClass
 
 /**
  * Updates the Java code of a message type which qualifies as [EntityState] by
- * making it implement this interface.
+ * making it implement this interface, or an interface derived from [EntityState].
+ *
+ * The type of the selected interface is defined by the value of
+ * the [kind][EntityOption.Kind] property of [EntityOption].
+ *
+ * ## API Note
  *
  * The class is public because its fully qualified name is used as a default
  * value in [EntitySettings][io.spine.tools.core.jvm.gradle.settings.EntitySettings].
@@ -69,15 +85,28 @@ public class ImplementEntityState(
 
     override fun doRender() {
         val idFieldType = type.firstField.javaType(typeSystem)
+        val option = type.option<EntityOption>()
+        val entityOption = option.unpack<EntityOption>()
+        val iface = entityStateInterface(entityOption)
         val action = ImplementInterface(
             type,
             file,
             superInterface {
-                name = EntityState::class.java.reference
+                name = iface.java.reference
                 genericArgument.add(idFieldType)
             },
             context
         )
         action.render()
     }
 }
+
+private fun entityStateInterface(option: EntityOption): KClass<out EntityState<*>> {
+    return when (option.kind) {
+        AGGREGATE -> AggregateState::class
+        PROCESS_MANAGER -> ProcessManagerState::class
+        PROJECTION -> ProjectionState::class
+        ENTITY -> EntityState::class
+        else -> error("Unable to convert the entity kind: `${option.kind}`.")
+    }
+}