Add basic exporter

.gitignore

@@ -35,3 +35,4 @@ out/
 
 ### VS Code ###
 .vscode/
+*.lst

build.gradle.kts

@@ -26,6 +26,7 @@ repositories {
 
 dependencies {
 	implementation("org.springframework.boot:spring-boot-starter-web")
+	testImplementation("junit:junit:4.13.1")
 	compileOnly("org.projectlombok:lombok")
 	annotationProcessor("org.projectlombok:lombok")
 	testImplementation("org.springframework.boot:spring-boot-starter-test")

src/main/java/org/misoenergy/hackday/kessel_run/PCGenExporter.java

@@ -0,0 +1,33 @@
+package org.misoenergy.hackday.kessel_run;
+
+import java.io.File;
+import java.io.IOException;
+
+public class PCGenExporter {
+
+    public PCGenExporter() {
+    }
+
+    public void export(File file) {
+        try {
+            createOutputFile(file);
+        } catch (IOException e) {
+            handleFailedOutput(e);
+        }
+    }
+
+    private void createOutputFile(File file) throws IOException {
+        if (file.createNewFile()) {
+            System.out.println("File created: " + file.getName());
+        } else {
+            System.out.println("File already exists. Deleting and re-running");
+            file.delete();
+            createOutputFile(file);
+        }
+    }
+
+    private void handleFailedOutput(Exception e) {
+        System.out.println("An error occurred.");
+        e.printStackTrace();
+    }
+}

src/test/java/org/misoenergy/hackday/kessel_run/KesselRunApplicationTests.java

@@ -3,6 +3,12 @@ package org.misoenergy.hackday.kessel_run;
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;
 
+import java.io.File;
+import java.io.IOException;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.internal.verification.VerificationModeFactory.times;
+
 @SpringBootTest
 class KesselRunApplicationTests {
 

src/test/java/org/misoenergy/hackday/kessel_run/PCGenExporterTest.java

@@ -0,0 +1,58 @@
+package org.misoenergy.hackday.kessel_run;
+
+import org.junit.jupiter.api.Test;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.io.*;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+@RunWith(MockitoJUnitRunner.class)
+public class PCGenExporterTest {
+
+
+    PCGenExporter exporter;
+
+    @Test
+    void exporterExists() {
+        exporter = new PCGenExporter();
+    }
+
+    @Test
+    void exporterCreatesFileWhenNoneExists() {
+        exporter = new PCGenExporter();
+        File file = new File("sw5eClasses.lst");
+        deleteFileIfExists(file);
+        exporter.export(file);
+        assertTrue(file.isFile());
+    }
+
+    @Test
+    void exporterRecreatesFileWhenExists() throws IOException {
+        exporter = new PCGenExporter();
+        File file = new File("sw5eClasses.lst");
+
+        deleteFileIfExists(file);
+        createFileWithData(file);
+
+        exporter.export(file);
+        BufferedReader reader = new BufferedReader(new FileReader(file));
+
+        assertTrue(reader.readLine() == null);
+
+    }
+
+    void deleteFileIfExists(File file) {
+        if(!file.exists()) {
+            file.delete();
+        }
+    }
+
+    void createFileWithData(File file) throws IOException {
+        FileWriter writer = new FileWriter(file);
+        writer.write("If this exists when tested, Fail!");
+        writer.close();
+    }
+}