From d16d7deb1b3c5b2b2b35109dfea935e65860a02e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=A9lio=20Costa?= <tweenzx@gmail.com>
Date: Thu, 8 Oct 2026 18:42:52 -0300
Subject: [PATCH] Add a CI lint job: javac -Xlint:all as errors and javadoc
 doclint

A new `lint` job (JDK 21) runs `mvn -P lint test-compile javadoc:javadoc`:
main and test sources compile with -Xlint:all and fail on any warning, and
javadoc runs with doclint (every group but `missing`) and fails on any
warning, so a broken reference or bad HTML in a doc comment fails the PR
instead of shipping in the Maven Central javadoc jar. The settings live in a
`lint` profile, so the JDK 11/17/21 test matrix is unchanged.

MillionSendException now declares serialVersionUID (the only -Xlint finding),
set to the value the JVM already computed for it, so its serialized form is
unchanged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .github/workflows/ci.yml                      | 11 +++++++
 pom.xml                                       | 31 +++++++++++++++++++
 .../com/millionsend/MillionSendException.java |  3 ++
 3 files changed, 45 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7e46954..58336c6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,3 +22,14 @@ jobs:
           java-version: ${{ matrix.java }}
           cache: maven
       - run: mvn -q -B verify
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4.4.0
+      - uses: actions/setup-java@cf277c60eb25467037889841efdb72551f06f6c3 # v4.9.1
+        with:
+          distribution: temurin
+          java-version: '21'
+          cache: maven
+      - run: mvn -B -ntp -P lint test-compile javadoc:javadoc
diff --git a/pom.xml b/pom.xml
index d60e8ac..67fdf30 100644
--- a/pom.xml
+++ b/pom.xml
@@ -72,6 +72,37 @@
   </build>
 
   <profiles>
+    <!--
+      CI's `lint` job, on the newest JDK only: -Xlint categories vary by javac
+      version, so the test matrix stays out of it. Doclint skips `missing`
+      because getters and builder methods carry no doc comment.
+    -->
+    <profile>
+      <id>lint</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-compiler-plugin</artifactId>
+            <configuration>
+              <failOnWarning>true</failOnWarning>
+              <compilerArgs>
+                <arg>-Xlint:all</arg>
+              </compilerArgs>
+            </configuration>
+          </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-javadoc-plugin</artifactId>
+            <version>3.12.0</version>
+            <configuration>
+              <doclint>all,-missing</doclint>
+              <failOnWarnings>true</failOnWarnings>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
     <!--
       Central Portal release: sources + javadoc jars, GPG signatures, and the
       Central bundle upload are release-only requirements — the profile keeps
diff --git a/src/main/java/com/millionsend/MillionSendException.java b/src/main/java/com/millionsend/MillionSendException.java
index a5754a4..5360923 100644
--- a/src/main/java/com/millionsend/MillionSendException.java
+++ b/src/main/java/com/millionsend/MillionSendException.java
@@ -10,6 +10,9 @@
  */
 public class MillionSendException extends Exception {
 
+  // The default the JVM computed before this was declared, so the serialized form is unchanged.
+  private static final long serialVersionUID = -5469809787528467192L;
+
   private final String name;
   private final Integer statusCode;