Added log4j and a basic test class

build.gradle

@@ -25,6 +25,10 @@ repositories {
 }
 
 dependencies {
+    // Log4J does logging. We'll meet it properly in a later week...
+    implementation 'org.apache.logging.log4j:log4j-api:2.12.0'
+    implementation 'org.apache.logging.log4j:log4j-core:2.12.0'
+
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.0'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
 }

src/main/java/dotsandboxes/DotsAndBoxesUI.java

@@ -79,6 +79,10 @@ public class DotsAndBoxesUI {
                     grid.drawHorizontal(x, y, grid.getPlayer());
                 } catch (IllegalStateException ex) {
                     // do nothing
+                    // This is a little artificial, as normally we'd implement this with a check that the line isn't
+                    // already "drawn" and then not calling the function. But for the exercise, we wanted students
+                    // to write a test that would ensure an exception is thrown, so we're relying on an exception
+                    // being thrown!
                 }});
 
                 AnchorPane.setLeftAnchor(line, 0.0 + gap + dotDiameter + col * (gap + lineLength + gap + dotDiameter));

src/main/java/module-info.java

@@ -14,5 +14,6 @@
 module dotsAndBoxes {
     requires javafx.graphics;
     requires javafx.controls;
+    requires org.apache.logging.log4j;
     exports dotsandboxes;
 }
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src/test/java/dotsandboxes/DotsAndBoxesGridTest.java

+package dotsandboxes;
+
+import org.junit.jupiter.api.*;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assumptions.*;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class DotsAndBoxesGridTest {
+    /*
+     * Because Test classes are classes, they can have fields, and can have static fields.
+     * This field is a logger. Loggers are like a more advanced println, for writing messages out to the console or a log file.
+     */
+    private static final Logger logger = LogManager.getLogger(DotsAndBoxesGridTest.class);
+
+    /*
+     * Tests are functions that have an @Test annotation before them.
+     * The typical format of a test is that it contains some code that does something, and then one
+     * or more assertions to check that a condition holds.
+     *
+     * This is a dummy test just to show that the test suite itself runs
+     */
+    @Test
+    public void testTestSuiteRuns() {
+        logger.info("Dummy test to show the test suite runs");
+        assertTrue(true);
+    }
+
+    // FIXME: You need to write tests for the two known bugs in the code.
+}

src/test/resources/log4j2.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="WARN">
+    <Appenders>
+        <Console name="Console" target="SYSTEM_OUT">
+            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
+        </Console>
+    </Appenders>
+    <Loggers>
+        <Root level="debug">
+            <AppenderRef ref="Console"/>
+        </Root>
+    </Loggers>
+</Configuration>
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