diff --git a/.gitignore b/.gitignore
index 05d601f..866c9fd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,6 +39,7 @@ target/
 
 # Test
 test-output/
+scripts/codacy-coverage-reporter-assembly.jar
 
 # Local helpers
 local/
diff --git a/.travis.yml b/.travis.yml
index db0b00b..68bb321 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,9 +14,9 @@ install:
   - ant package
 
 script:
+  - xvfb-run ant report
   - docker run -v=$(pwd):/app --workdir=/app coala/base coala --ci
-  - ant report
 
 after_success:
   - curl https://secure.central.sonatype.com/maven2/com/codacy/codacy-coverage-reporter/1.0.13/codacy-coverage-reporter-1.0.13-assembly.jar > codacy-coverage-reporter-assembly.jar
-  - java -cp codacy-coverage-reporter-assembly.jar com.codacy.CodacyCoverageReporter -l Java -r test/site/jacoco/report.xml
+  - java -cp codacy-coverage-reporter-assembly.jar com.codacy.CodacyCoverageReporter -l Java -r test-output/site/jacoco/report.xml
diff --git a/lib/test/commons-io-2.5-javadoc.jar b/lib/test/commons-io-2.5-javadoc.jar
new file mode 100644
index 0000000..b957529
Binary files /dev/null and b/lib/test/commons-io-2.5-javadoc.jar differ
diff --git a/lib/test/commons-io-2.5.jar b/lib/test/commons-io-2.5.jar
new file mode 100644
index 0000000..1234918
Binary files /dev/null and b/lib/test/commons-io-2.5.jar differ
diff --git a/scripts/upload-coverage-report.sh b/scripts/upload-coverage-report.sh
new file mode 100755
index 0000000..8fd4c30
--- /dev/null
+++ b/scripts/upload-coverage-report.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+root=$(dirname "${BASH_SOURCE}")/..
+
+# Download https://secure.central.sonatype.com/maven2/com/codacy/codacy-coverage-reporter/1.0.13/codacy-coverage-reporter-1.0.13-assembly.jar
+# curl https://secure.central.sonatype.com/maven2/com/codacy/codacy-coverage-reporter/1.0.13/codacy-coverage-reporter-1.0.13-assembly.jar > codacy-coverage-reporter-assembly.jar
+cd ${root}
+# Set the token first: 
+# export CODACY_PROJECT_TOKEN=%Project_Token%
+COMMIT=$(git log -n 1 --pretty=format:"%H")
+echo ${COMMIT}
+java -cp ./scripts/codacy-coverage-reporter-assembly.jar com.codacy.CodacyCoverageReporter -l Java --commitUUID ${COMMIT} -r ./test-output/site/jacoco/report.xml
+cd - > /dev/null
diff --git a/src/rprocessing/Runner.java b/src/rprocessing/Runner.java
index 85fcf1f..d4a7a22 100644
--- a/src/rprocessing/Runner.java
+++ b/src/rprocessing/Runner.java
@@ -1,11 +1,11 @@
 package rprocessing;
 
 import org.renjin.eval.EvalException;
+
 import rprocessing.exception.NotFoundException;
 import rprocessing.exception.REvalException;
 import rprocessing.lancher.StandaloneSketch;
 import rprocessing.util.Printer;
-import rprocessing.util.RScriptReader;
 import rprocessing.util.StreamPrinter;
 
 /**
@@ -17,11 +17,11 @@ public class Runner {
 
   public static RunnableSketch sketch;
 
-  @SuppressWarnings("unused")
-  private static final String CORE_TEXT =
-      RScriptReader.readResourceAsText(Runner.class, "r/core.R");
+  // private static final String CORE_TEXT =
+  // RScriptReader.readResourceAsText(Runner.class, "r/core.R");
 
-  private static final boolean VERBOSE = Boolean.parseBoolean(System.getenv("VERBOSE_RLANG_MODE"));
+  private static final boolean VERBOSE = Boolean.parseBoolean(System
+      .getenv("VERBOSE_RLANG_MODE"));
 
   private static void log(final Object... objs) {
     if (!VERBOSE) {
@@ -39,7 +39,8 @@ public static void main(final String[] args) throws Exception {
     }
     try {
       sketch = new StandaloneSketch(args);
-      runSketchBlocking(sketch, new StreamPrinter(System.out), new StreamPrinter(System.err));
+      runSketchBlocking(sketch, new StreamPrinter(System.out), new StreamPrinter(
+          System.err));
     } catch (final Throwable t) {
       System.err.println(t);
       System.exit(-1);
@@ -47,14 +48,15 @@ public static void main(final String[] args) throws Exception {
   }
 
   public static synchronized void runSketchBlocking(final RunnableSketch sketch,
-      final Printer stdout, final Printer stderr) throws REvalException, NotFoundException {
+      final Printer stdout, final Printer stderr) throws REvalException,
+      NotFoundException {
     runSketchBlocking(sketch, stdout, stderr, null);
   }
 
   public static synchronized void runSketchBlocking(final RunnableSketch sketch,
       final Printer stdout, final Printer stderr,
-      final SketchPositionListener sketchPositionListener)
-      throws REvalException, NotFoundException {
+      final SketchPositionListener sketchPositionListener) throws REvalException,
+      NotFoundException {
     final String[] args = sketch.getPAppletArguments();
 
     log("Tring to initialize RLangPApplet.");
diff --git a/src/test/e2e/core/E2eTestBase.java b/src/test/e2e/core/E2eTestBase.java
new file mode 100644
index 0000000..637b461
--- /dev/null
+++ b/src/test/e2e/core/E2eTestBase.java
@@ -0,0 +1,55 @@
+package test.e2e.core;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import rprocessing.Runner;
+import test.e2e.util.ImageUtils;
+import test.e2e.util.TempFile;
+
+public abstract class E2eTestBase {
+
+  protected static float THRESHOLD = (float) 0.01;
+  protected static String SAVE_CODE_TEMPLATE = "processing$saveFrame(\"%s\")\nprocessing$exit()";
+
+  protected String code;
+  protected String coreCode;
+  protected String referenceURI;
+
+  protected String referenceImage(String path) throws MalformedURLException {
+    return "https://processing.org/reference/images/" + path;
+  }
+
+  protected float diffImage(File file, String fileURL) throws MalformedURLException, IOException {
+    return ImageUtils.DiffImage(file, new URL(fileURL));
+  }
+
+  protected float diffImageWithProcessingReference(File file, String referenceURL)
+      throws MalformedURLException, IOException {
+    return diffImage(file, referenceImage(referenceURL));
+  }
+
+  protected void runSketch(String path) throws Exception {
+    String[] args = new String[] {path};
+    Runner.main(args);
+  }
+
+  protected void defaultOperation() throws Exception {
+    // Create temp sketch file and image file.
+    File saveFile = TempFile.createTempImage();
+    code = assembleCode(saveFile.getCanonicalPath());
+    File sketchFile = TempFile.createSketchTempFile(code);
+    System.out.println("## Code to test\n");
+    System.out.println(code);
+
+    // Run the sketch and save the image to saveFile.
+    this.runSketch(sketchFile.getCanonicalPath());
+
+    assert (diffImageWithProcessingReference(saveFile, referenceURI) < THRESHOLD);
+  }
+
+  protected String assembleCode(String filename) {
+    return coreCode + "\n" + String.format(SAVE_CODE_TEMPLATE, filename);
+  }
+}
diff --git a/src/test/e2e/core/primitives2d/TriangleTest.java b/src/test/e2e/core/primitives2d/TriangleTest.java
new file mode 100644
index 0000000..6439183
--- /dev/null
+++ b/src/test/e2e/core/primitives2d/TriangleTest.java
@@ -0,0 +1,27 @@
+package test.e2e.core.primitives2d;
+
+import static org.junit.Assert.fail;
+import org.junit.Test;
+import test.e2e.core.E2eTestBase;
+
+/**
+ * 
+ * @author github.com/gaocegege
+ */
+public class TriangleTest extends E2eTestBase {
+
+  public TriangleTest() {
+    coreCode = "processing$triangle(30, 75, 58, 20, 86, 75)";
+    referenceURI = "triangle_.png";
+  }
+
+  @Test
+  public void test() {
+    try {
+      defaultOperation();
+    } catch (Exception exception) {
+      System.err.println(exception);
+      fail("Should not have thrown any exception");
+    }
+  }
+}
diff --git a/src/test/e2e/util/ImageUtils.java b/src/test/e2e/util/ImageUtils.java
new file mode 100644
index 0000000..6b75ebe
--- /dev/null
+++ b/src/test/e2e/util/ImageUtils.java
@@ -0,0 +1,45 @@
+package test.e2e.util;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+
+import javax.imageio.ImageIO;
+
+import processing.core.PApplet;
+import processing.core.PImage;
+
+/**
+ * 
+ * @author github.com/gaocegege
+ */
+public class ImageUtils {
+  public static float DiffImage(File actualFile, URL testURL) throws IOException {
+    PImage actualImage = new PImage(ImageIO.read(actualFile));
+    PImage testImage = new PImage(ImageIO.read(testURL));
+
+    return imgDifference(actualImage, testImage);
+  }
+
+  private static float imgDifference(PImage i0, PImage i1) {
+    float diff = 0;
+    i0.loadPixels();
+    int[] ip0 = i0.pixels;
+    i1.loadPixels();
+    int[] ip1 = i1.pixels;
+    for (int n = 0; n < ip0.length; n++) {
+      int pxl0 = ip0[n], r0, g0, b0;
+      int pxl1 = ip1[n], r1, g1, b1;
+      r0 = (pxl0 >> 20) & 0xF;
+      g0 = (pxl0 >> 12) & 0xF;
+      b0 = (pxl0 >> 4) & 0xF;
+      r1 = (pxl1 >> 20) & 0xF;
+      g1 = (pxl1 >> 12) & 0xF;
+      b1 = (pxl1 >> 4) & 0xF;
+      diff += PApplet.abs(r0 - r1) + PApplet.abs(g0 - g1) + PApplet.abs(b0 - b1);
+    }
+    // Each colour channel can have a difference 0-15
+    // Considering 3 colour channels (ignoring alpha)
+    return diff / (ip0.length * 3 * 15);
+  }
+}
diff --git a/src/test/e2e/util/TempFile.java b/src/test/e2e/util/TempFile.java
new file mode 100644
index 0000000..e422021
--- /dev/null
+++ b/src/test/e2e/util/TempFile.java
@@ -0,0 +1,34 @@
+package test.e2e.util;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import org.apache.commons.io.FileUtils;
+
+/**
+ * TempFile creates the tempfile and delete it when exits.
+ * 
+ * @author github.com/gaocegege
+ */
+public class TempFile {
+  private static String SKETCH_PREFIX = "Processing.R.";
+  private static String SKETCH_SUFFIX = ".tmp.rpde";
+  private static String PNG_SUFFIX = ".tmp.png";
+
+  public static File createTempImage() throws IOException {
+    // this temporary file remains after the jvm exits.
+    File tempFile = File.createTempFile(SKETCH_PREFIX, PNG_SUFFIX);
+    tempFile.deleteOnExit();
+
+    return tempFile;
+  }
+
+  public static File createSketchTempFile(String code) throws IOException {
+    // this temporary file remains after the jvm exits.
+    File tempFile = File.createTempFile(SKETCH_PREFIX, SKETCH_SUFFIX);
+    tempFile.deleteOnExit();
+
+    FileUtils.writeStringToFile(tempFile, code, Charset.defaultCharset());
+    return tempFile;
+  }
+}