First integration test

pom.xml

@@ -103,6 +103,17 @@
             <version>3.8.1</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.junit.vintage</groupId>
+                    <artifactId>junit-vintage-engine</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
 
         <dependency>
             <groupId>org.junit.jupiter</groupId>
@@ -172,6 +183,21 @@
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>2.22.2</version>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <version>2.22.2</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>integration-test</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <trimStackTrace>false</trimStackTrace>
+                </configuration>
+            </plugin>
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>

src/test/java/edu/kit/typicalc/view/AbstractIT.java

@@ -0,0 +1,27 @@
+package edu.kit.typicalc.view;
+
+import org.junit.Before;
+import org.junit.Rule;
+
+import com.vaadin.testbench.IPAddress;
+import com.vaadin.testbench.ScreenshotOnFailureRule;
+import com.vaadin.testbench.TestBenchTestCase;
+import org.openqa.selenium.firefox.FirefoxDriver;
+
+/**
+ * Base class for all our integration tests, allowing us to change the applicable driver,
+ * test URL or other configurations in one place.
+ */
+public abstract class AbstractIT extends TestBenchTestCase {
+
+    @Rule
+    public ScreenshotOnFailureRule rule = new ScreenshotOnFailureRule(this,
+            true);
+
+    @Before
+    public void setUp() {
+        setDriver(new FirefoxDriver());
+        getDriver().get("http://127.0.0.1:8080");
+    }
+
+}

src/test/java/edu/kit/typicalc/view/ScreenshotIT.java

@@ -0,0 +1,93 @@
+package edu.kit.typicalc.view;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+
+import edu.kit.typicalc.view.main.MainViewImpl;
+import org.junit.Test;
+import org.openqa.selenium.HasCapabilities;
+
+import com.vaadin.testbench.Parameters;
+import com.vaadin.testbench.commands.TestBenchCommandExecutor;
+
+/**
+ * This example contains usage examples of screenshot comparison feature.
+ * <p>
+ */
+public class ScreenshotIT extends AbstractIT {
+
+    /**
+     * We'll want to perform some additional setup functions, so we override the
+     * setUp() method.
+     */
+    @Override
+    public void setUp() {
+        super.setUp();
+
+        // Set a fixed viewport size so the screenshot is always the same
+        // resolution
+        testBench().resizeViewPortTo(1000, 500);
+
+        // Define the directory for reference screenshots and for error files
+        Parameters.setScreenshotReferenceDirectory("src/test/resources/screenshots");
+        Parameters.setScreenshotErrorDirectory("target/screenshot_errors");
+    }
+
+    @Test
+    public void initialView() throws Exception {
+        // Change this calculation after running the test once to see how errors
+        // in screenshots are verified.
+        // The output is placed in target/screenshot_errors
+
+        generateReferenceIfNotFound("initialView");
+
+        // Compare screen with reference image with id "oneplustwo" from the
+        // reference image directory. Reference image filenames also contain
+        // browser, version and platform.
+        assertTrue(
+                "Screenshot comparison for 'initialView' failed, see "
+                        + Parameters.getScreenshotErrorDirectory()
+                        + " for error images",
+                testBench().compareScreen("initialView"));
+    }
+
+    /**
+     * Generates a reference screenshot if no reference exists.
+     * <p>
+     * This method only exists for demonstration purposes. Normally you should
+     * perform this task manually after verifying that the screenshots look
+     * correct.
+     *
+     * @param referenceId
+     *            the id of the reference image
+     * @throws IOException
+     */
+    private void generateReferenceIfNotFound(String referenceId)
+            throws IOException {
+        String refName = ((TestBenchCommandExecutor) testBench())
+                .getReferenceNameGenerator().generateName(referenceId,
+                        ((HasCapabilities) getDriver()).getCapabilities());
+        File referenceFile = new File(
+                Parameters.getScreenshotReferenceDirectory(), refName + ".png");
+        if (referenceFile.exists()) {
+            return;
+        }
+
+        if (!referenceFile.getParentFile().exists()) {
+            referenceFile.getParentFile().mkdirs();
+        }
+
+        File errorFile = new File(Parameters.getScreenshotErrorDirectory(),
+                referenceFile.getName());
+
+        // Take a screenshot and move it to the reference location
+        testBench().compareScreen(referenceId);
+        errorFile.renameTo(referenceFile);
+
+        System.out.println("Created new reference file in " + referenceFile);
+
+    }
+
+}

src/test/resources/checkstyle-suppressions.xml

@@ -5,5 +5,6 @@
 
 <suppressions>
   <suppress files="src/main/resources/*" checks=".*" />
+  <suppress files="src/test/resources/*" checks=".*" />
 </suppressions>