Improve code readability.

codegen-plugin/src/main/kotlin/io/spine/protodata/hello/CodeGenPlugin.kt

@@ -72,7 +72,7 @@ public class SizeOptionView : View<SizeOptionId,
             event.option.value,
             ArrayOfSizeOption::class.java
         )
-        builder().setSizeExpression(value.value)
+        builder().setValidationExpression(value.value)
     }
 }
 
@@ -86,9 +86,9 @@ private class SizeOptionViewRepository : ViewRepository<SizeOptionId,
         { message: FieldOptionDiscovered, _: EventContext? ->
             EventRoute.withId(
                 SizeOptionId.newBuilder()
-                    .setFile(message.file)
-                    .setType(message.type)
-                    .setField(message.field)
+                    .setFilePath(message.file)
+                    .setTypeName(message.type)
+                    .setFieldName(message.field)
                     .build()
             )
         }

codegen-plugin/src/main/kotlin/io/spine/protodata/hello/ProtobufSourceFileExt.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2023, 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.protodata.hello
+
+import com.google.protobuf.StringValue
+import io.spine.protobuf.AnyPacker
+import io.spine.protodata.ProtobufSourceFile
+
+internal fun ProtobufSourceFile.javaPackage(): String {
+
+    val optionName = "java_package"
+
+    val option = file.optionList.find {
+        it.name == optionName
+    }
+    check(option != null) { "Cannot find option '$optionName'" }
+
+    return AnyPacker.unpack(
+        option.value,
+        StringValue::class.java
+    ).value
+}
+
+internal fun ProtobufSourceFile.fieldNames(typeName: String): Iterable<String> {
+
+    val type = typeMap.values.find {
+        it.name.simpleName == typeName
+    }
+    check(type != null) { "Cannot find type '$typeName' in $filePath" }
+    return type.fieldList.map { it.name.value }
+}

codegen-plugin/src/main/kotlin/io/spine/protodata/hello/ValidateSizeOptionRenderer.kt

@@ -25,11 +25,9 @@
  */
 package io.spine.protodata.hello
 
-import com.google.protobuf.StringValue
 import com.squareup.kotlinpoet.ClassName
 import com.squareup.kotlinpoet.FileSpec
 import com.squareup.kotlinpoet.FunSpec
-import io.spine.protobuf.AnyPacker
 import io.spine.protodata.ProtobufSourceFile
 import io.spine.protodata.renderer.Renderer
 import io.spine.protodata.renderer.SourceFileSet
@@ -55,33 +53,33 @@ public class ValidateSizeOptionRenderer : Renderer<Kotlin>(Kotlin.lang()) {
         sizeOption: SizeOption,
         sources: SourceFileSet
     ) {
-        val protoFile = select<ProtobufSourceFile>().all().find {
-            it.file.path.value == sizeOption.id.file.value
+        val protobufSourceFile = select<ProtobufSourceFile>().all().find {
+            it.file.path.value == sizeOption.id.filePath.value
         }
-        check(protoFile != null) {
-            "Cannot find file: " + sizeOption.id.file.value
+        check(protobufSourceFile != null) {
+            "Cannot find 'ProtobufSourceFile' for " +
+                    sizeOption.id.filePath.value
         }
 
-        val className = sizeOption.id.type.simpleName
-        val fieldName = propertyName(sizeOption.id.field.value)
-        val packageName = javaPackageOption(protoFile)
-        val protoFieldNames = collectFieldNamesForType(className, protoFile)
-        val expression = buildExpression(
-            sizeOption.sizeExpression,
-            protoFieldNames
+        val packageName = protobufSourceFile.javaPackage()
+        val typeName = sizeOption.id.typeName.simpleName
+        val fieldName = sizeOption.id.fieldName.value.camelCase()
+        val validationExpression = buildExpression(
+            sizeOption.validationExpression,
+            protobufSourceFile.fieldNames(typeName)
         )
         val filePath = Path.of(
             packageName.replace('.', '/'),
-            className + "Ext.kt"
+            typeName + "Ext.kt"
         )
 
         sources.createFile(
             filePath,
             generateFileContent(
                 packageName,
-                className,
+                typeName,
                 fieldName,
-                expression
+                validationExpression
             )
         )
     }
@@ -95,13 +93,15 @@ private fun generateFileContent(
 ) = FileSpec.builder(ClassName(packageName, typeName))
     .indent("    ")
     .addFunction(
-        FunSpec.builder("validate" + fieldName.camelCase() + "Count")
+        FunSpec.builder("validate" + fieldName + "Count")
             .receiver(ClassName(packageName, typeName, "Builder"))
             .beginControlFlow(
-                "check(%LCount == %L)", fieldName, expression
+                "check(%LCount == %L)",
+                fieldName.propertyName(),
+                expression
             )
             .addStatement(
-                "\"'%L' count does not match the validation expression.\"",
+                "\"%L count does not match the validation expression.\"",
                 fieldName
             )
             .endControlFlow()
@@ -112,41 +112,12 @@ private fun generateFileContent(
 
 private fun buildExpression(
     expression: String,
-    protoFieldNames: List<String>
-): String {
-    var result = expression
-    protoFieldNames.forEach { result = result.replace(it, propertyName(it)) }
-    return result
-}
-
-private fun javaPackageOption(protoFile: ProtobufSourceFile): String {
-
-    val optionName = "java_package"
-
-    val option = protoFile.file.optionList.find {
-        it.name == optionName
+    snakeCaseFieldNames: Iterable<String>
+) = mutableListOf(expression)
+    .plus(snakeCaseFieldNames)
+    .reduce { result, snakeCaseName ->
+        result.replace(snakeCaseName, snakeCaseName.propertyName())
     }
-    check(option != null) { "Cannot find option: $optionName" }
-
-    return AnyPacker.unpack(
-        option.value,
-        StringValue::class.java
-    ).value
-}
-
-private fun collectFieldNamesForType(
-    simpleTypeName: String,
-    protoFile: ProtobufSourceFile
-): List<String> {
-
-    val type = protoFile.typeMap.values.find {
-        it.name.simpleName == simpleTypeName
-    }
-    check(type != null) {
-        "Cannot find type '$simpleTypeName' in $protoFile"
-    }
-    return type.fieldList.map { it.name.value }
-}
 
-private fun propertyName(protoFieldName: String) =
-    protoFieldName.camelCase().replaceFirstChar { it.lowercase() }
+private fun String.propertyName() =
+    camelCase().replaceFirstChar { it.lowercase() }

codegen-plugin/src/main/proto/spine/protodata/hello/size_option.proto

@@ -32,7 +32,7 @@ import "spine/options.proto";
 
 option (type_url_prefix) = "type.spine.io";
 option java_package = "io.spine.protodata.hello";
-option java_outer_classname = "SizeOptionProjectionProto";
+option java_outer_classname = "SizeOptionProto";
 option java_multiple_files = true;
 
 import "spine/protodata/ast.proto";
@@ -42,14 +42,14 @@ message SizeOption {
 
   SizeOptionId id = 1;
 
-  string size_expression = 2;
+  string validation_expression = 2;
 }
 
 message SizeOptionId {
 
-  spine.protodata.FilePath file = 1;
+  spine.protodata.FilePath file_path = 1;
 
-  spine.protodata.TypeName type = 2;
+  spine.protodata.TypeName type_name = 2;
 
-  spine.protodata.FieldName field = 3;
+  spine.protodata.FieldName field_name = 3;
 }

model/src/test/kotlin/io/spine/protodata/hello/BoardBuilderExtTest.kt

@@ -34,22 +34,14 @@ class `Board builder extension should` {
     @Test
     fun `validate cell count`() {
 
-        Board.newBuilder()
-            .setSideSize(3)
+        val sideSize = 3
+        val builder = Board.newBuilder()
+            .setSideSize(sideSize)
 
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-            .addCell(Cell.newBuilder())
-
-            .validateCellCount()
+        repeat(sideSize * sideSize) {
+            builder.addCell(Cell.newBuilder())
+        }
+        builder.validateCellCount()
     }
 
     @Test