Handle compare_by option

buildSrc/src/main/kotlin/io/spine/internal/dependency/ProtoData.kt

@@ -73,7 +73,7 @@ object ProtoData {
      * The version of ProtoData dependencies.
      */
     val version: String
-    private const val fallbackVersion = "0.61.5"
+    private const val fallbackVersion = "0.61.7"
 
     /**
      * The distinct version of ProtoData used by other build tools.
@@ -82,7 +82,7 @@ object ProtoData {
      * transitional dependencies, this is the version used to build the project itself.
      */
     val dogfoodingVersion: String
-    private const val fallbackDfVersion = "0.61.5"
+    private const val fallbackDfVersion = "0.61.7"
 
     /**
      * The artifact for the ProtoData Gradle plugin.

buildSrc/src/main/kotlin/io/spine/internal/dependency/Spine.kt

@@ -76,7 +76,7 @@ object Spine {
          * @see [Spine.CoreJava.server]
          * @see <a href="https://github.com/SpineEventEngine/core-java">core-java</a>
          */
-        const val core = "2.0.0-SNAPSHOT.176"
+        const val core = "2.0.0-SNAPSHOT.177"
 
         /**
          * The version of [Spine.modelCompiler].

mc-java-annotation/src/main/kotlin/io/spine/tools/mc/annotation/FileOptionsProcess.kt

@@ -38,12 +38,12 @@ import io.spine.protodata.ast.event.FileExited
 import io.spine.protodata.ast.event.FileOptionDiscovered
 import io.spine.server.entity.alter
 import io.spine.server.entity.state
+import io.spine.server.event.NoReaction
 import io.spine.server.event.React
 import io.spine.server.procman.ProcessManager
 import io.spine.server.query.select
 import io.spine.tools.mc.annotation.ApiOption.Companion.findMatching
 import io.spine.tools.mc.annotation.event.fileOptionMatched
-import io.spine.server.model.Nothing as NoEvents
 
 /**
  * Transforms options defined in a Protobuf file into events that match
@@ -59,23 +59,23 @@ internal class FileOptionsProcess : ProcessManager<File, FileOptions, FileOption
      * values are set to `true`.
      */
     @React
-    fun on(@External e: FileEntered): NoEvents {
+    fun on(@External e: FileEntered): NoReaction {
         alter {
             file = e.file
         }
-        return nothing()
+        return noReaction()
     }
 
     @React
-    fun on(@External e: FileOptionDiscovered): NoEvents {
+    fun on(@External e: FileOptionDiscovered): NoReaction {
         val isApiLevelOption = findMatching(e.option) != null
         val optionValue = e.option.value
         if (isApiLevelOption && optionValue.isTrue()) {
             alter {
                 addOption(e.option)
             }
         }
-        return nothing()
+        return noReaction()
     }
 
     @React

mc-java-annotation/src/main/kotlin/io/spine/tools/mc/java/annotation/OuterClassAnnotationDiscovery.kt

@@ -31,12 +31,12 @@ import io.spine.protodata.ast.File
 import io.spine.protodata.ast.event.FileEntered
 import io.spine.protodata.java.javaMultipleFiles
 import io.spine.server.entity.alter
+import io.spine.server.event.NoReaction
 import io.spine.server.event.React
 import io.spine.server.procman.ProcessManager
 import io.spine.server.procman.ProcessManagerRepository
 import io.spine.server.route.EventRouting
 import io.spine.tools.mc.annotation.ApiOption.Companion.findMatching
-import io.spine.server.model.Nothing as NoEvents
 
 /**
  * A process manager which discovers the API annotation options set on the outer
@@ -48,7 +48,7 @@ internal class OuterClassAnnotationDiscovery:
     ProcessManager<File, OuterClassAnnotations, OuterClassAnnotations.Builder>() {
 
     @React
-    fun on(@External e: FileEntered): NoEvents {
+    fun on(@External e: FileEntered): NoReaction {
         // The check here is a safety net. We should get only events for
         // proto files with `java_multiple_files` set to `true`. See `Repository.setEventRouting`.
         if (!e.header.javaMultipleFiles()) {
@@ -67,7 +67,7 @@ internal class OuterClassAnnotationDiscovery:
                 }
             }
         }
-        return nothing()
+        return noReaction()
     }
 
     class Repository :

mc-java-base/src/main/kotlin/io/spine/tools/mc/java/OverrideAnnotation.kt

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2024, 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.mc.java
+
+import com.intellij.psi.PsiAnnotation
+import io.spine.tools.java.reference
+import io.spine.tools.mc.java.OverrideAnnotation.create
+import io.spine.tools.psi.java.Environment.elementFactory
+
+/**
+ * Creates a [PsiAnnotation] for marking overridden methods.
+ *
+ * ## Implementation note
+ * We do not cache the created instance of [PsiAnnotation] because PSI elements are mutable.
+ * We want to avoid unwanted propagation of modifications made by one renderer to others.
+ *
+ * @see create
+ */
+public object OverrideAnnotation {
+
+    /**
+     * Creates a new [PsiAnnotation] with [Override].
+     */
+    public fun create(): PsiAnnotation {
+        val reference = Override::class.java.reference
+        val annotation = elementFactory.createAnnotationFromText("@$reference", null)
+        return annotation
+    }
+}

mc-java-base/src/main/kotlin/io/spine/tools/mc/java/base/FieldPathExts.kt

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2024, 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
+ *
+ * http://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.mc.java.base
+
+import io.spine.base.FieldPath
+import io.spine.base.fieldPath
+import io.spine.protodata.ast.Field
+import io.spine.protodata.ast.MessageType
+import io.spine.protodata.ast.field
+import io.spine.protodata.ast.isMessage
+import io.spine.protodata.type.TypeSystem
+
+/**
+ * Tells if this [FieldPath] doesn't denote a nested field.
+ */
+public val FieldPath.isNotNested: Boolean
+    get() = fieldNameList.size == 1
+
+/**
+ * Returns this [FieldPath] as a single [String], where the field names
+ * are separated with a dot.
+ *
+ * For example, `citizen.passport.firstName`.
+ */
+public val FieldPath.joined: String
+    get() = fieldNameList.joinToString(".")
+
+/**
+ * Returns the root field's name of this [FieldPath].
+ *
+ * @throws [NoSuchElementException] if the path is empty.
+ */
+public val FieldPath.root: String
+    get() = fieldNameList.first()
+
+/**
+ * Resolves the given [FieldPath] against the given [MessageType] within
+ * this [TypeSystem].
+ *
+ * This method navigates through the nested messages and fields as specified by
+ * the [fieldPath], returning the final [Field] that the path points to.
+ *
+ * @param fieldPath The field path to resolve.
+ * @param message The message where the root of the [fieldPath] is declared.
+ */
+public fun TypeSystem.resolve(fieldPath: FieldPath, message: MessageType): Field {
+    val currentField = message.field(fieldPath.root)
+    if (fieldPath.isNotNested) {
+        return currentField
+    }
+
+    check(currentField.type.isMessage) {
+        "Can't resolve the field path `$fieldPath` because `${currentField.name}` segment " +
+                "doesn't denote a message. The type of this field is `${currentField.type}`. " +
+                "Only messages can have nested field."
+    }
+
+    val currentFieldMessage = currentField.type.message
+    val remainingFields = fieldPath.fieldNameList.drop(1)
+    val remainingPath = fieldPath { fieldName.addAll(remainingFields) }
+    val nextMessageInfo = findMessage(currentFieldMessage)
+
+    check(nextMessageInfo != null) {
+        "`$currentFieldMessage` was not found in the passed Proto files or their dependencies."
+    }
+
+    val nextMessage = nextMessageInfo.first
+    return resolve(remainingPath, nextMessage)
+}

mc-java-base/src/main/kotlin/io/spine/tools/mc/java/field/AddFieldClass.kt

@@ -92,13 +92,12 @@ public open class AddFieldClass(
 
     private fun PsiClass.addTopLevelFieldMethods() {
         type.fieldList.forEach {
-            val accessor = TopLevelFieldAccessor(it, fieldSupertype, typeSystem!!)
+            val accessor = TopLevelFieldAccessor(it, fieldSupertype, typeSystem)
             addLast(accessor.method())
         }
     }
 
     private fun PsiClass.addFieldClasses() {
-        val typeSystem = typeSystem!!
         val deps = MessageTypeDependencies(type, setOf(SINGLE, ONEOF_NAME), typeSystem).asSet()
         deps.forEach {
             val fld = MessageTypedField(it, fieldSupertype, typeSystem)

mc-java-base/src/main/kotlin/io/spine/tools/mc/java/gradle/settings/CodegenSettings.kt

@@ -93,6 +93,11 @@ public class CodegenSettings @Internal public constructor(private val project: P
      */
     public val uuids: UuidSettings = UuidSettings(project)
 
+    /**
+     * Settings for the generated code of comparable messages.
+     */
+    public val comparables: ComparableSettings = ComparableSettings(project)
+
     /**
      * Settings for the generated validation code.
      */
@@ -187,6 +192,13 @@ public class CodegenSettings @Internal public constructor(private val project: P
         action.execute(uuids)
     }
 
+    /**
+     * Configures code generation for comparable messages.
+     */
+    public fun forComparables(action: Action<ComparableSettings>) {
+        action.execute(comparables)
+    }
+
     /**
      * Configures code generation for validation messages.
      */
@@ -212,6 +224,7 @@ public class CodegenSettings @Internal public constructor(private val project: P
             entities = self.entities.toProto()
             validation = self.validation.toProto()
             uuids = self.uuids.toProto()
+            comparables = self.comparables.toProto()
             classpath = cp
         }
     }

mc-java-base/src/main/kotlin/io/spine/tools/mc/java/gradle/settings/ComparableSettings.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2024, 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.mc.java.gradle.settings
+
+import io.spine.tools.mc.java.settings.Comparables
+import io.spine.tools.mc.java.settings.comparables
+import io.spine.tools.mc.java.settings.noParameter
+import org.gradle.api.Project
+
+/**
+ * Code generation settings for messages that have `compare_by` option.
+ */
+public class ComparableSettings(project: Project) :
+    SettingsWithActions<Comparables>(project, DEFAULT_ACTIONS) {
+
+    override fun toProto(): Comparables = comparables {
+        actions = actions()
+    }
+}
+
+/**
+ * The actions applied by default to comparable messages.
+ */
+private val DEFAULT_ACTIONS = mapOf(
+    "io.spine.tools.mc.java.comparable.action.AddComparator" to noParameter,
+    "io.spine.tools.mc.java.comparable.action.AddCompareTo" to noParameter,
+    "io.spine.tools.mc.java.comparable.action.ImplementComparable" to noParameter,
+)

mc-java-base/src/main/proto/spine/tools/mc/java/settings.proto

@@ -70,6 +70,9 @@ message Combined {
 
     // The classpath used to lookup types by their fully-qualified names.
     tools.java.Classpath classpath = 8;
+
+    // The code generation settings for comparable messages.
+    Comparables comparables = 11;
 }
 
 // Configuration related to validation code.
@@ -227,3 +230,12 @@ message Uuids {
     protodata.Actions actions = 3;
 }
 
+// Code generation settings for comparable messages.
+//
+// A message is comparable when it has `compare_by` option.
+//
+message Comparables {
+
+    // A collection of code generation actions.
+    protodata.Actions actions = 1;
+}

mc-java-base/src/testFixtures/kotlin/io/spine/tools/mc/java/Assertions.kt

@@ -33,6 +33,6 @@ import kotlin.text.RegexOption.DOT_MATCHES_ALL
  * Tells if [javaCode] contains a class which implements the given [superInterface].
  */
 fun implementsInterface(javaCode: String, superInterface: Class<*>): Boolean {
-    val regex = Regex("""implements.*${superInterface.reference}""", DOT_MATCHES_ALL)
+    val regex = Regex("implements[^{}]*${superInterface.reference}[^{}]*\\{", DOT_MATCHES_ALL)
     return regex.containsMatchIn(javaCode)
 }