GH-438: Implement initial incremental compilation mechanism

pom.xml

@@ -99,6 +99,7 @@
     <!-- Dependencies -->
     <assertj.version>3.26.3</assertj.version>
     <immutables.version>2.10.1</immutables.version>
+    <jackson-bom.version>2.16.1</jackson-bom.version>
     <javax-annotation.version>1.3.2</javax-annotation.version>
     <jspecify.version>1.0.0</jspecify.version>
     <junit.version>5.11.3</junit.version>
@@ -152,6 +153,14 @@
 
   <dependencyManagement>
     <dependencies>
+      <dependency>
+        <groupId>com.fasterxml.jackson</groupId>
+        <artifactId>jackson-bom</artifactId>
+        <version>${jackson-bom.version}</version>
+        <scope>import</scope>
+        <type>pom</type>
+      </dependency>
+
       <dependency>
         <groupId>com.github.marschall</groupId>
         <artifactId>memoryfilesystem</artifactId>

protobuf-maven-plugin/pom.xml

@@ -34,27 +34,21 @@
     <maven>3.8.2</maven>
   </prerequisites>
 
-  <dependencyManagement>
-    <dependencies>
-      <dependency>
-        <groupId>org.junit</groupId>
-        <artifactId>junit-bom</artifactId>
-        <version>${junit.version}</version>
-        <scope>import</scope>
-        <type>pom</type>
-      </dependency>
-
-      <dependency>
-        <groupId>org.mockito</groupId>
-        <artifactId>mockito-bom</artifactId>
-        <version>${mockito.version}</version>
-        <scope>import</scope>
-        <type>pom</type>
-      </dependency>
-    </dependencies>
-  </dependencyManagement>
-
   <dependencies>
+    <dependency>
+      <!-- Used for the incremental cache file format. -->
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <scope>compile</scope>
+    </dependency>
+
+    <dependency>
+      <!-- Serialization of java.time classes -->
+      <groupId>com.fasterxml.jackson.datatype</groupId>
+      <artifactId>jackson-datatype-jsr310</artifactId>
+      <scope>compile</scope>
+    </dependency>
+
     <dependency>
       <groupId>javax.annotation</groupId>
       <artifactId>javax.annotation-api</artifactId>

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/invoker.properties

@@ -0,0 +1,19 @@
+#
+# Copyright (C) 2023 - 2024, Ashley Scopes.
+#
+# 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
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+invoker.goals.0=clean
+invoker.goals.1=package
+invoker.goals.2=package

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/pom.xml

@@ -0,0 +1,62 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (C) 2023 - 2024, Ashley Scopes.
+
+    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
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>@project.groupId@.it</groupId>
+    <artifactId>integration-test-parent</artifactId>
+    <version>@project.version@</version>
+    <relativePath>../setup/pom.xml</relativePath>
+  </parent>
+
+  <groupId>gh-438-incremental-compilation-no-changes</groupId>
+  <artifactId>gh-438-incremental-compilation-no-changes</artifactId>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java</artifactId>
+      <scope>compile</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>@project.groupId@</groupId>
+        <artifactId>@project.artifactId@</artifactId>
+
+        <configuration>
+          <incrementalCompilation>true</incrementalCompilation>
+        </configuration>
+
+        <executions>
+          <execution>
+            <goals>
+              <goal>generate</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/src/main/protobuf/org/example/avatar.proto

@@ -0,0 +1,33 @@
+//
+// Copyright (C) 2023 - 2024, Ashley Scopes.
+//
+// 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+package org.example;
+
+option java_multiple_files = true;
+option java_package = "org.example.users";
+
+enum AvatarFormat {
+  PNG = 0;
+  WEBP = 1;
+  SVG = 2;
+}
+
+message Avatar {
+  string binary_data = 1;
+  AvatarFormat format = 2;
+}

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/src/main/protobuf/org/example/channel.proto

@@ -0,0 +1,27 @@
+//
+// Copyright (C) 2023 - 2024, Ashley Scopes.
+//
+// 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+package org.example;
+
+option java_multiple_files = true;
+option java_package = "org.example";
+
+message Channel {
+  string id = 1;
+  string name = 2;
+}

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/src/main/protobuf/org/example/message.proto

@@ -0,0 +1,32 @@
+//
+// Copyright (C) 2023 - 2024, Ashley Scopes.
+//
+// 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+package org.example;
+
+option java_multiple_files = true;
+option java_package = "org.example";
+
+import "org/example/user.proto";
+import "org/example/channel.proto";
+
+message Message {
+  string id = 1;
+  string content = 2;
+  org.example.User author = 3;
+  org.example.Channel channel = 4;
+}

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/src/main/protobuf/org/example/user.proto

@@ -0,0 +1,31 @@
+//
+// Copyright (C) 2023 - 2024, Ashley Scopes.
+//
+// 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
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+syntax = "proto3";
+
+package org.example;
+
+option java_multiple_files = true;
+option java_package = "org.example";
+
+import "org/example/avatar.proto";
+
+message User {
+  string id = 1;
+  string name = 2;
+  optional string nickname = 3;
+  optional org.example.Avatar avatar = 4;
+}

protobuf-maven-plugin/src/it/gh-438-incremental-compilation-no-changes/test.groovy

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2023 - 2024, Ashley Scopes.
+ *
+ * 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.nio.file.Path
+
+Path baseDirectory = basedir.toPath().toAbsolutePath()
+
+return true