[mvn] exec:java become final part of phase test

README.md

@@ -9,20 +9,19 @@ Requirements
 - Maven
 - Java SDK (21 here but it shouldn't matter)
 
-Build
+Build and use
 -----
 
-    mvn clean install
-
-Usage
------
-
-    mvn exec:java -Day=1
-    mvn exec:java -Day=10
-    mvn exec:java
+    mvn test -Day=1
+    mvn test -Day=10
+    mvn test
 
 When no day is given, it assumes today.
 
+From IntelliJ, you may run `mvn test` via the Maven panel.
+Access the Maven panel via its button on the right top bar,
+or via View>Tool Windows.
+
 Contributing
 ------------
 
@@ -31,7 +30,3 @@ Most of your work should go to implement the methods `String part1()` and `Strin
 
 The superclass `Day` provides a constructor to fetch the inputs `day1.input1`, ..., `day10.input`, ... 
 from `src/(main|test)/resources`.
-
-In development, you might want to chain the Maven goals:
-
-    mvn clean install exec:java

pom.xml

@@ -12,8 +12,6 @@
         <maven.compiler.source>21</maven.compiler.source>
         <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <exec.mainClass>${project.groupId}.Main</exec.mainClass>
-        <exec.args>${ay}</exec.args>
         <ay>${maven.build.timestamp}</ay>
         <maven.build.timestamp.format>d</maven.build.timestamp.format>
     </properties>
@@ -26,4 +24,25 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <version>3.1.1</version>
+                <executions>
+                    <execution>
+                        <phase>test</phase>
+                        <goals>
+                            <goal>java</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <mainClass>${project.groupId}.Main</mainClass>
+                    <arguments>${ay}</arguments>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>
\ No newline at end of file