diff --git a/graphwalker-cli/src/main/java/org/graphwalker/cli/CLI.java b/graphwalker-cli/src/main/java/org/graphwalker/cli/CLI.java
index 82ea9140..e287db84 100644
--- a/graphwalker-cli/src/main/java/org/graphwalker/cli/CLI.java
+++ b/graphwalker-cli/src/main/java/org/graphwalker/cli/CLI.java
@@ -101,19 +101,20 @@ enum Command {
   public static void main(String[] args) {
     CLI cli = new CLI();
     try {
-      cli.run(args);
+      int status = cli.run(args);
+      System.exit(status);
     } catch (Exception e) {
       // We should have caught all exceptions up until here, but there
       // might have been problems with the command parser for instance...
       System.err.println(e + System.lineSeparator());
-      logger.error("An error occurred when running command: " + StringUtils.join(args, " "), e);
+      logger.error("An unexpected error occurred when running command: " + StringUtils.join(args, " "), e);
     }
   }
 
   /**
    * Parses the command line.
    */
-  private void run(String[] args) {
+  public int run(String[] args) {
     Options options = new Options();
     JCommander jc = new JCommander(options);
     jc.setProgramName("graphwalker");
@@ -145,12 +146,12 @@ private void run(String[] args) {
 
       if (options.help) {
         jc.usage();
-        return;
+        return 0;
       } else if (options.version) {
         System.out.println(printVersionInformation());
-        return;
+        return 0;
       } else if (jc.getParsedCommand() == null) {
-        throw new MissingCommandException("Missing a command. Add '--help'");
+        throw new MissingCommandException("Missing a command. Use the '--help' option to list all available commands.");
       }
 
       // Parse for commands
@@ -174,19 +175,24 @@ private void run(String[] args) {
         runCommandSource();
       } else if (jc.getParsedCommand().equalsIgnoreCase("check")) {
         command = Command.CHECK;
-        runCommandCheck();
+        return runCommandCheck();
       }
     } catch (UnsupportedFileFormat | MissingCommandException e) {
       System.err.println(e.getMessage() + System.lineSeparator());
+      return 1;
     } catch (ParameterException e) {
-      System.err.println("An error occurred when running command: " + StringUtils.join(args, " "));
+      System.err.println("An error occurred when running command: '" + StringUtils.join(args, " ") + "'.");
       System.err.println(e.getMessage() + System.lineSeparator());
       jc.usage();
+      return 1;
     } catch (Exception e) {
-      System.err.println("An error occurred when running command: " + StringUtils.join(args, " "));
-      System.err.println(e.getMessage() + System.lineSeparator());
       logger.error("An error occurred when running command: " + StringUtils.join(args, " "), e);
+      System.err.println("An error occurred when running command: '" + StringUtils.join(args, " ") + "'.");
+      System.err.println(e.getMessage() + System.lineSeparator());
+      return 2;
     }
+
+    return 0;
   }
 
   private void setLogLevel(Options options) {
@@ -210,7 +216,7 @@ private void setLogLevel(Options options) {
     }
   }
 
-  private void runCommandCheck() throws Exception, UnsupportedFileFormat {
+  private int runCommandCheck() throws Exception, UnsupportedFileFormat {
     List<Context> contexts = getContextsWithPathGenerators(check.model.iterator());
     if (check.blocked) {
       org.graphwalker.io.common.Util.filterBlockedElements(contexts);
@@ -221,8 +227,10 @@ private void runCommandCheck() throws Exception, UnsupportedFileFormat {
       for (String issue : issues) {
         System.out.println(issue);
       }
+      return 1;
     } else {
       System.out.println("No issues found with the model(s).");
+      return 0;
     }
   }
 
@@ -252,7 +260,7 @@ private void runCommandMethods() throws Exception, UnsupportedFileFormat {
 
     for (Context context : contexts) {
       for (Vertex.RuntimeVertex vertex : context.getModel().getVertices()) {
-        if (null != vertex.getName()) {
+        if (vertex.getName() != null) {
           names.add(vertex.getName());
         }
       }
@@ -296,6 +304,7 @@ private void runCommandOnline() throws Exception, UnsupportedFileFormat {
         + online.port
         + "/graphwalker/getNext");
       System.out.println("Press Control+C to end...");
+
       try {
         server.start();
         Thread.currentThread().join();
@@ -308,7 +317,7 @@ private void runCommandOnline() throws Exception, UnsupportedFileFormat {
         server.stop();
       }
     } else {
-      throw new ParameterException("--service expected either WEBSOCKET or RESTFUL");
+      throw new ParameterException("--service expected either WEBSOCKET or RESTFUL.");
     }
   }
 
@@ -320,8 +329,9 @@ private void runCommandConvert() throws Exception, UnsupportedFileFormat {
     try {
       contexts = inputFactory.create(Paths.get(inputFileName));
     } catch (DslException e) {
-      System.err.println("When parsing model: '" + inputFileName + "' " + e.getMessage() + System.lineSeparator());
-      throw new Exception("Model syntax error");
+      throw new Exception("The following syntax error occurred when parsing: '" + inputFileName + "'."
+                          + System.lineSeparator()
+                          + "Syntax Error: " + e.getMessage() + System.lineSeparator());
     }
 
     if (convert.blocked) {
@@ -343,11 +353,12 @@ private void runCommandSource() throws Exception, UnsupportedFileFormat {
       contexts = inputFactory.create(Paths.get(modelFileName));
       if (isNullOrEmpty(contexts)) {
         logger.error("No valid models found in: " + modelFileName);
-        throw new RuntimeException("No valid models found in: " + modelFileName);
+        throw new RuntimeException("No valid models found in: '" + modelFileName + "'.");
       }
     } catch (DslException e) {
-      System.err.println("When parsing model: '" + modelFileName + "' " + e.getMessage() + System.lineSeparator());
-      throw new Exception("Model syntax error");
+      throw new Exception("The following syntax error occurred when parsing: '" + modelFileName + "'."
+                          + System.lineSeparator()
+                          + "Syntax Error: " + e.getMessage());
     }
 
     if (source.blocked) {
@@ -376,7 +387,7 @@ private void runCommandSource() throws Exception, UnsupportedFileFormat {
         }
       } catch (IOException e) {
         logger.error(e.getMessage());
-        throw new RuntimeException("Could not read the file: " + templateFileName);
+        throw new RuntimeException("Could not read the file: '" + templateFileName + "'.");
       }
       String templateStr = templateStrBuilder.toString();
 
@@ -446,10 +457,12 @@ public List<Context> getContextsWithPathGenerators(Iterator itr) throws Exceptio
       try {
         contexts = factory.create(Paths.get(modelFileName));
       } catch (DslException e) {
-        System.err.println("When parsing model: '" + modelFileName + "' " + e.getMessage() + System.lineSeparator());
-        throw new Exception("Model syntax error");
+        throw new Exception("The following syntax error occurred when parsing: '" + modelFileName + "'."
+                            + System.lineSeparator()
+                            + "Syntax Error: " + e.getMessage());
       }
-      // TODO fix all occurences of get(0) is not safe
+
+      // TODO fix all occurrences of get(0) is not safe
       contexts.get(0).setPathGenerator(GeneratorFactory.parse((String) itr.next()));
 
       if (triggerOnce &&
@@ -464,9 +477,9 @@ public List<Context> getContextsWithPathGenerators(Iterator itr) throws Exceptio
         }
 
         if (elements == null) {
-          throw new ParameterException("--start-element Did not find matching element in the model: " + modelFileName);
+          throw new ParameterException("--start-element Did not find matching element in the model: '" + modelFileName + "'.");
         } else if (elements.size() > 1) {
-          throw new ParameterException("--start-element There are more than one matching element in the model: " + modelFileName);
+          throw new ParameterException("--start-element There are more than one matching element in the model: '" + modelFileName + "'.");
         }
         contexts.get(0).setNextElement(elements.get(0));
       }
@@ -501,8 +514,9 @@ private List<Context> getContexts(Iterator itr) throws Exception, UnsupportedFil
       try {
         contexts = factory.create(Paths.get(modelFileName));
       } catch (DslException e) {
-        System.err.println("When parsing model: '" + modelFileName + "' " + e.getMessage() + System.lineSeparator());
-        throw new Exception("Model syntax error");
+        throw new Exception("The following syntax error occurred when parsing: '" + modelFileName + "'."
+                            + System.lineSeparator()
+                            + "Syntax Error: " + e.getMessage());
       }
       executionContexts.addAll(contexts);
     }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/CLITestRoot.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/CLITestRoot.java
index 8a9d6dee..3761cdae 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/CLITestRoot.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/CLITestRoot.java
@@ -12,10 +12,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -49,17 +49,23 @@ protected Result runCommand(String args[]) {
     System.setOut(outStream);
     System.setErr(errStream);
 
+    int status = -1;
+
     try {
-      CLI.main(args);
+      CLI cli = new CLI();
+      status = cli.run(args);
     } finally {
       System.setOut(oldOutStream);
       System.setErr(oldErrStream);
 
       String outMsg = stdOutput.toString();
       String errMsg = errOutput.toString();
+
       logger.info("stdout: " + outMsg);
       logger.info("stderr: " + errMsg);
-      return new Result(outMsg, errMsg);
+      logger.info("status: " + status);
+
+      return new Result(outMsg, errMsg, status);
     }
   }
 
@@ -82,10 +88,12 @@ public class Result {
 
     private final String output;
     private final String error;
+    private final int status;
 
-    public Result(String output, String error) {
+    public Result(String output, String error, int status) {
       this.output = output;
       this.error = error;
+      this.status = status;
     }
 
     public String getOutput() {
@@ -95,5 +103,9 @@ public String getOutput() {
     public String getError() {
       return error;
     }
+
+    public int getStatus() {
+      return status;
+    }
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/CheckTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/CheckTest.java
index 91ddf664..fba60dd4 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/CheckTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/CheckTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -41,6 +41,7 @@ public class CheckTest extends CLITestRoot {
   public void check() throws IOException {
     String args[] = {"check", "-m", "graphml/online/ShoppingCart.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), containsString("No issues found with the model(s)."));
   }
@@ -49,6 +50,7 @@ public void check() throws IOException {
   public void checkWithBlocked() throws IOException {
     String args[] = {"check", "-m", "graphml/online/ShoppingCart.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), containsString("No issues found with the model(s)."));
   }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/ConvertFilesTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/ConvertFilesTest.java
index e32f852a..9f54eece 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/ConvertFilesTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/ConvertFilesTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -46,8 +46,9 @@ public class ConvertFilesTest extends CLITestRoot {
   public void convertGraphmlToJava() throws IOException {
     String args[] = {"convert", "--input", "graphml/UC01_GW2.graphml", "--format", "java"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
-    //TODO:Fix test
-//    Assert.assertTrue(tempFile.length() > 0);
+    // TODO: Fix test
+    // assertTrue(tempFile.length() > 0);
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/CorrectModelsTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/CorrectModelsTest.java
index 3071ffc5..a556bd26 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/CorrectModelsTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/CorrectModelsTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -67,9 +67,10 @@ public class CorrectModelsTest extends CLITestRoot {
   public void simplestModel() {
     String args[] = {"offline", "-m", "graphml/CorrectModels/simplestModel.graphml", "random(vertex_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), is("{\"currentElementName\":\"e1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v1\"}" + System.lineSeparator()));
+                                      "{\"currentElementName\":\"v1\"}" + System.lineSeparator()));
   }
 
   /**
@@ -79,17 +80,18 @@ public void simplestModel() {
   public void shortestAllPathsVertexCoverage() {
     String args[] = {"offline", "-m", "graphml/CorrectModels/shortestAllPathsVertexCoverage.graphml", "shortest_all_paths(vertex_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), is("{\"currentElementName\":\"e1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v2\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e4\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v4\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e6\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e3\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v3\"}" + System.lineSeparator()));
+                                      "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v2\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e4\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v4\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e6\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e3\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v3\"}" + System.lineSeparator()));
   }
 
   /**
@@ -99,6 +101,7 @@ public void shortestAllPathsVertexCoverage() {
   public void loginNoErrors() {
     String args[] = {"offline", "-o", "-m", "graphml/Login.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
   }
 
@@ -109,11 +112,12 @@ public void loginNoErrors() {
   public void noStartVertex() {
     String args[] = {"offline", "-e", "v1", "-m", "graphml/CorrectModels/modelWithNoStartVertex.graphml", "a_star(reached_edge(e4))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), is("{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v2\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e4\"}" + System.lineSeparator()));
+                                      "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v2\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e4\"}" + System.lineSeparator()));
   }
 
   /**
@@ -123,11 +127,12 @@ public void noStartVertex() {
   public void dontUseBlocked() {
     String args[] = {"offline", "-b", "false", "-m", "graphml/CorrectModels/blockedVertex.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), is("{\"currentElementName\":\"e1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v2\"}" + System.lineSeparator()));
+                                      "{\"currentElementName\":\"v1\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"e2\"}" + System.lineSeparator() +
+                                      "{\"currentElementName\":\"v2\"}" + System.lineSeparator()));
   }
 
   /**
@@ -137,9 +142,10 @@ public void dontUseBlocked() {
   public void useBlocked() {
     String args[] = {"offline", "-m", "graphml/CorrectModels/blockedVertex.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), is("{\"currentElementName\":\"e1\"}" + System.lineSeparator() +
-                                             "{\"currentElementName\":\"v1\"}" + System.lineSeparator()));
+                                      "{\"currentElementName\":\"v1\"}" + System.lineSeparator()));
   }
 
   /**
@@ -149,23 +155,24 @@ public void useBlocked() {
   public void dontUseBlockedJson() {
     String args[] = {"offline", "-b", "false", "-g", "json/graphWithBlockedElements.json"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(Arrays.asList(result.getOutput().split(System.lineSeparator())),
-                      hasItems("{\"currentElementName\":\"e1\"}",
-                               "{\"currentElementName\":\"e2\"}",
-                               "{\"currentElementName\":\"e3\"}",
-                               "{\"currentElementName\":\"e4\"}",
-                               "{\"currentElementName\":\"e5\"}",
-                               "{\"currentElementName\":\"e6\"}",
-                               "{\"currentElementName\":\"e7\"}",
-                               "{\"currentElementName\":\"e8\"}",
-                               "{\"currentElementName\":\"e9\"}",
-                               "{\"currentElementName\":\"e10\"}",
-                               "{\"currentElementName\":\"v1\"}",
-                               "{\"currentElementName\":\"v2\"}",
-                               "{\"currentElementName\":\"v3\"}",
-                               "{\"currentElementName\":\"v4\"}",
-                               "{\"currentElementName\":\"v5\"}"));
+               hasItems("{\"currentElementName\":\"e1\"}",
+                        "{\"currentElementName\":\"e2\"}",
+                        "{\"currentElementName\":\"e3\"}",
+                        "{\"currentElementName\":\"e4\"}",
+                        "{\"currentElementName\":\"e5\"}",
+                        "{\"currentElementName\":\"e6\"}",
+                        "{\"currentElementName\":\"e7\"}",
+                        "{\"currentElementName\":\"e8\"}",
+                        "{\"currentElementName\":\"e9\"}",
+                        "{\"currentElementName\":\"e10\"}",
+                        "{\"currentElementName\":\"v1\"}",
+                        "{\"currentElementName\":\"v2\"}",
+                        "{\"currentElementName\":\"v3\"}",
+                        "{\"currentElementName\":\"v4\"}",
+                        "{\"currentElementName\":\"v5\"}"));
   }
 
   /**
@@ -175,23 +182,24 @@ public void dontUseBlockedJson() {
   public void useBlockedJson() {
     String args[] = {"offline", "-g", "json/graphWithBlockedElements.json"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(Arrays.asList(result.getOutput().split(System.lineSeparator())),
-                      hasItems("{\"currentElementName\":\"e1\"}",
-                               "{\"currentElementName\":\"e2\"}",
-                               "{\"currentElementName\":\"e3\"}",
-                               "{\"currentElementName\":\"e4\"}",
-                               "{\"currentElementName\":\"e7\"}",
-                               "{\"currentElementName\":\"e8\"}",
-                               "{\"currentElementName\":\"e9\"}",
-                               "{\"currentElementName\":\"v1\"}",
-                               "{\"currentElementName\":\"v2\"}",
-                               "{\"currentElementName\":\"v3\"}",
-                               "{\"currentElementName\":\"v4\"}"));
+               hasItems("{\"currentElementName\":\"e1\"}",
+                        "{\"currentElementName\":\"e2\"}",
+                        "{\"currentElementName\":\"e3\"}",
+                        "{\"currentElementName\":\"e4\"}",
+                        "{\"currentElementName\":\"e7\"}",
+                        "{\"currentElementName\":\"e8\"}",
+                        "{\"currentElementName\":\"e9\"}",
+                        "{\"currentElementName\":\"v1\"}",
+                        "{\"currentElementName\":\"v2\"}",
+                        "{\"currentElementName\":\"v3\"}",
+                        "{\"currentElementName\":\"v4\"}"));
 
     assertThat(Arrays.asList(result.getOutput().split(System.lineSeparator())),
-                      not(hasItems("{\"currentElementName\":\"e5\"}",
-                                   "{\"currentElementName\":\"e6\"}",
-                                   "{\"currentElementName\":\"v5\"}")));
+               not(hasItems("{\"currentElementName\":\"e5\"}",
+                            "{\"currentElementName\":\"e6\"}",
+                            "{\"currentElementName\":\"v5\"}")));
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/IOErrorsTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/IOErrorsTest.java
index 5f6ef434..e30eedaf 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/IOErrorsTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/IOErrorsTest.java
@@ -12,10 +12,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -41,9 +41,10 @@ public class IOErrorsTest extends CLITestRoot {
   public void nonExistentFile() {
     String args[] = {"offline", "-m", "sdsdtkdsjhsl.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
-    assertThat(result.getError(), is("An error occurred when running command: " +
-                                            "offline -m sdsdtkdsjhsl.graphml random(edge_coverage(100))" +
-                                            System.lineSeparator() + "Could not read the file." + System.lineSeparator() + System.lineSeparator()));
+    assertThat(result.getStatus(), is(2));
     assertThat(result.getOutput(), is(""));
+    assertThat(result.getError(), is("An error occurred when running command: 'offline -m sdsdtkdsjhsl.graphml random(edge_coverage(100))'."
+                                     + System.lineSeparator()
+                                     + "Could not read the file." + System.lineSeparator() + System.lineSeparator()));
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/IncorrectModelsTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/IncorrectModelsTest.java
index f9a43ea5..9e7a6bba 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/IncorrectModelsTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/IncorrectModelsTest.java
@@ -12,10 +12,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -42,12 +42,11 @@ public void wrongVertexSyntax() {
     String args[] = {"offline", "-m", "graphml/IncorrectModels/wrongVertexSyntax.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
     assertThat(result.getError(),
-                      is("When parsing model: 'graphml/IncorrectModels/wrongVertexSyntax.graphml' The string '1' did not conform to GraphWalker syntax rules."
-                         + System.lineSeparator()
-                         + System.lineSeparator()
-                         + "An error occurred when running command: offline -m graphml/IncorrectModels/wrongVertexSyntax.graphml random(edge_coverage(100))"
-                         + System.lineSeparator()
-                         + "Model syntax error" + System.lineSeparator() + System.lineSeparator()));
+               is("An error occurred when running command: 'offline -m graphml/IncorrectModels/wrongVertexSyntax.graphml random(edge_coverage(100))'."
+                  + System.lineSeparator()
+                  + "The following syntax error occurred when parsing: 'graphml/IncorrectModels/wrongVertexSyntax.graphml'."
+                  + System.lineSeparator()
+                  + "Syntax Error: The string '1' did not conform to GraphWalker syntax rules." + System.lineSeparator() + System.lineSeparator()));
     assertThat(result.getOutput(), is(""));
   }
 
@@ -58,9 +57,9 @@ public void wrongVertexSyntax() {
   public void onlyOneVertex() {
     String args[] = {"offline", "-m", "graphml/IncorrectModels/singleVertex.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
-    assertThat(result.getError(), is("An error occurred when running command: " +
-                                            "offline -m graphml/IncorrectModels/singleVertex.graphml random(edge_coverage(100))" +
-                                            System.lineSeparator() + "No start context found" + System.lineSeparator() + System.lineSeparator()));
+    assertThat(result.getError(), is("An error occurred when running command: 'offline -m graphml/IncorrectModels/singleVertex.graphml random(edge_coverage(100))'."
+                                     + System.lineSeparator()
+                                     + "No start context found" + System.lineSeparator() + System.lineSeparator()));
     assertThat(result.getOutput(), is(""));
   }
 
@@ -71,9 +70,9 @@ public void onlyOneVertex() {
   public void singleStartVertex() {
     String args[] = {"offline", "-m", "graphml/IncorrectModels/singleStartVertex.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
-    assertThat(result.getError(), is("An error occurred when running command: " +
-                                            "offline -m graphml/IncorrectModels/singleStartVertex.graphml random(edge_coverage(100))" +
-                                            System.lineSeparator() + "No start context found" + System.lineSeparator() + System.lineSeparator()));
+    assertThat(result.getError(), is("An error occurred when running command: 'offline -m graphml/IncorrectModels/singleStartVertex.graphml random(edge_coverage(100))'."
+                                     + System.lineSeparator()
+                                     + "No start context found" + System.lineSeparator() + System.lineSeparator()));
     assertThat(result.getOutput(), is(""));
   }
 
@@ -85,12 +84,11 @@ public void badEdgeName() {
     String args[] = {"offline", "-m", "graphml/IncorrectModels/badEdgeName.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
     assertThat(result.getError(),
-                      is("When parsing model: 'graphml/IncorrectModels/badEdgeName.graphml' The string '1_badName' did not conform to GraphWalker syntax rules."
-                         + System.lineSeparator()
-                         + System.lineSeparator()
-                         + "An error occurred when running command: offline -m graphml/IncorrectModels/badEdgeName.graphml random(edge_coverage(100))"
-                         + System.lineSeparator()
-                         + "Model syntax error" + System.lineSeparator() + System.lineSeparator()));
+               is("An error occurred when running command: 'offline -m graphml/IncorrectModels/badEdgeName.graphml random(edge_coverage(100))'."
+                  + System.lineSeparator()
+                  + "The following syntax error occurred when parsing: 'graphml/IncorrectModels/badEdgeName.graphml'."
+                  + System.lineSeparator()
+                  + "Syntax Error: The string '1_badName' did not conform to GraphWalker syntax rules." + System.lineSeparator() + System.lineSeparator()));
     assertThat(result.getOutput(), is(""));
   }
 
@@ -102,12 +100,11 @@ public void badVertexName() {
     String args[] = {"offline", "-m", "graphml/IncorrectModels/badVertexName.graphml", "random(edge_coverage(100))"};
     Result result = runCommand(args);
     assertThat(result.getError(),
-                      is("When parsing model: 'graphml/IncorrectModels/badVertexName.graphml' The string '1_badName' did not conform to GraphWalker syntax rules."
-                         + System.lineSeparator()
-                         + System.lineSeparator()
-                         + "An error occurred when running command: offline -m graphml/IncorrectModels/badVertexName.graphml random(edge_coverage(100))"
-                         + System.lineSeparator()
-                         + "Model syntax error" + System.lineSeparator() + System.lineSeparator()));
+               is("An error occurred when running command: 'offline -m graphml/IncorrectModels/badVertexName.graphml random(edge_coverage(100))'."
+                  + System.lineSeparator()
+                  + "The following syntax error occurred when parsing: 'graphml/IncorrectModels/badVertexName.graphml'."
+                  + System.lineSeparator()
+                  + "Syntax Error: The string '1_badName' did not conform to GraphWalker syntax rules." + System.lineSeparator() + System.lineSeparator()));
     assertThat(result.getOutput(), is(""));
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/MethodsTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/MethodsTest.java
index 9d24f509..6dbbc8f7 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/MethodsTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/MethodsTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -44,39 +44,40 @@ public void methodsDontUseBlockedFeature() throws IOException {
     Result result = runCommand(args);
     assertThat(result.getError(), is(""));
     assertThat(Arrays.asList(result.getOutput().split("\\s+")),
-                      containsInAnyOrder("e1",
-                                         "e2",
-                                         "e3",
-                                         "e4",
-                                         "e5",
-                                         "e6",
-                                         "e7",
-                                         "e8",
-                                         "e9",
-                                         "e10",
-                                         "v1",
-                                         "v2",
-                                         "v3",
-                                         "v4",
-                                         "v5"));
+                containsInAnyOrder("e1",
+                                   "e2",
+                                   "e3",
+                                   "e4",
+                                   "e5",
+                                   "e6",
+                                   "e7",
+                                   "e8",
+                                   "e9",
+                                   "e10",
+                                   "v1",
+                                   "v2",
+                                   "v3",
+                                   "v4",
+                                   "v5"));
   }
 
   @Test
   public void methodsUseBlockedFeature() throws IOException {
     String args[] = {"methods", "-m", "json/graphWithBlockedElements.json"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(Arrays.asList(result.getOutput().split("\\s+")),
-                      containsInAnyOrder("e1",
-                                         "e2",
-                                         "e3",
-                                         "e4",
-                                         "e7",
-                                         "e8",
-                                         "e9",
-                                         "v1",
-                                         "v2",
-                                         "v3",
-                                         "v4"));
+               containsInAnyOrder("e1",
+                                  "e2",
+                                  "e3",
+                                  "e4",
+                                  "e7",
+                                  "e8",
+                                  "e9",
+                                  "v1",
+                                  "v2",
+                                  "v3",
+                                  "v4"));
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/OnlineTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/OnlineTest.java
index 91405a34..a5d9bf57 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/OnlineTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/OnlineTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintHelpTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintHelpTest.java
index 5ac67d31..89534215 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintHelpTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintHelpTest.java
@@ -41,6 +41,7 @@ public class PrintHelpTest extends CLITestRoot {
   public void help() throws IOException {
     String args[] = {"--help"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), containsString("Usage: graphwalker [options] [command] [command options]"));
   }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintVersionTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintVersionTest.java
index c39754ee..9a71cbdd 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintVersionTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/PrintVersionTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -41,6 +41,7 @@ public class PrintVersionTest extends CLITestRoot {
   public void version() throws IOException {
     String args[] = {"--version"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertThat(result.getOutput(), containsString("org.graphwalker version: "));
   }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/RequirementsTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/RequirementsTest.java
index e4de582e..c09cbf1e 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/RequirementsTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/RequirementsTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -43,6 +43,7 @@ public class RequirementsTest extends CLITestRoot {
   public void requirements() throws IOException {
     String args[] = {"requirements", "-m", "graphml/online/ShoppingCart.graphml"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
 
     List<String> array = Arrays.asList(result.getOutput().split("\n"));
@@ -50,10 +51,10 @@ public void requirements() throws IOException {
       array.set(i, array.get(i).trim());
     }
     assertThat(array,
-                      containsInAnyOrder("UC01 2.2.1",
-                                         "UC01 2.2.2",
-                                         "UC01 2.2.3",
-                                         "UC01 2.3",
-                                         "UC01 2.4"));
+              containsInAnyOrder("UC01 2.2.1",
+                                 "UC01 2.2.2",
+                                 "UC01 2.2.3",
+                                 "UC01 2.3",
+                                 "UC01 2.4"));
   }
 }
diff --git a/graphwalker-cli/src/test/java/org/graphwalker/cli/SourceTest.java b/graphwalker-cli/src/test/java/org/graphwalker/cli/SourceTest.java
index 4f460271..18bc9a89 100644
--- a/graphwalker-cli/src/test/java/org/graphwalker/cli/SourceTest.java
+++ b/graphwalker-cli/src/test/java/org/graphwalker/cli/SourceTest.java
@@ -10,10 +10,10 @@
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
- * 
+ *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -41,6 +41,7 @@ public class SourceTest extends CLITestRoot {
   public void generatePerl() throws IOException {
     String args[] = {"source", "--input", "json/example.json", "template/perl.template"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertTrue(result.getOutput().length() > 1200 && result.getOutput().length() < 1300);
   }
@@ -49,6 +50,7 @@ public void generatePerl() throws IOException {
   public void generatePython() throws IOException {
     String args[] = {"source", "--input", "json/example.json", "template/python.template"};
     Result result = runCommand(args);
+    assertThat(result.getStatus(), is(0));
     assertThat(result.getError(), is(""));
     assertTrue(result.getOutput().length() > 950 && result.getOutput().length() < 1150);
   }
diff --git a/pom.xml b/pom.xml
index d32f1a8a..22ee4d2c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -433,7 +433,7 @@
       <plugin>
         <groupId>org.jacoco</groupId>
         <artifactId>jacoco-maven-plugin</artifactId>
-        <version>0.8.7</version>
+        <version>0.8.8</version>
         <executions>
           <execution>
             <goals>