I wanted to write a test for a method in Groovy that throws an IOException. The only way for me to simulate this in the test is to force the method to throw this exception
This is what the original code looks like:
public void cleanUpBermudaFiles(RequestMessage requestMessage)
{
final File sourceDirectory = new File(preferenceService.getPreference("bermuda.landingstrip") + File.separator + requestMessage.getWorkflowId().getValue());
if(sourceDirectory!=null && sourceDirectory.exists())
{
deleteDirectory(sourceDirectory);
}
else
{
LOG.error("Directory must exist in order to delete");
}
}
private void deleteDirectory(File directoryToDelete)
{
try {
FileUtils.deleteDirectory(directoryToDelete);
} catch (Exception e) {
LOG.error("Failed to delete Bermuda files directory located at:" + directoryToDelete.getPath() + "with an exception" + e.getMessage());
}
}
MY TEST: (I'm looking for a way to make deleteDirectory throw IOException)
public void testCleanUpBermudaFailure()
{
workflowId = new WorkflowId("123456")
workflowDirectory = new File(srcDirectory, workflowId.value)
workflowDirectory.mkdir()
File.createTempFile('foo','.lst', workflowDirectory)
def exception = {throw new IOException()}
expect(mockRequestMessage.getWorkflowId()).andReturn(workflowId)
expect(mockPreferenceService.getPreference("bermuda.landingstrip")).andReturn(srcDirectory.path)
replay(mockPreferenceService, mockRequestMessage)
fileCleanUpService.preferenceService = mockPreferenceService
fileCleanUpService.metaClass.deleteDirectory = exception
fileCleanUpService.cleanUpBermudaFiles(mockRequestMessage)
verify(mockPreferenceService, mockRequestMessage)
assert srcDirectory.listFiles().length == 0, 'CleanUp failed'
}
If the service class is a Groovy class, you would want to mock FileUtils like:
FileUtils.metaClass.static.deleteDirectory = { File f -> throw new IOException() }
However, as ataylor pointed out, you cannot intercept calls if it's a Java class. You can find a nice blog post about it here.
You are mocking a no-arg call to deleteDirectory, but the real deleteDirectory takes one argument of type File. Try this:
def exception = { File directoryToDelete -> throw new IOException() }
...
fileCleanUpService.metaClass.deleteDirectory = exception
Related
I want to get the method name and line number when an error occur, I am using Core 5.
try
{
//My code
}
catch (Exception ex)
{
_logger.LogError(ex, "Method Name / Line Number");
}
Update:
I found a Solution like this:
_logger.LogError(ex, "\n=> ex Error: " + ex + "\n=> Action Name: " + ex.TargetSite.ReflectedType.Name + "\n=> Error Message: " + ex.Message + "\n=> Line Number: " + ex.LineNumber());
A simple call to ToString() on exception will give you the complete information needed. For example when we run the following code:
public static void Main()
{
try
{
//my code
throw new ArgumentException();
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
The output would be somewhat like:
System.ArgumentException: Value does not fall within the expected range.
at ConsoleApp.Program.Main() in C:\Users\USER\source\Playground\ConsoleApp1\Program.cs:line 20
where Main() is the method name and 20 is the line number.
To get the format as required in question we can write a wrapper around the exception and fetch the line number from it:
using System;
using System.Reflection;
namespace ConsoleApp
{
class Program
{
public static void Main()
{
try
{
//my code
throw new ArgumentException();
}
catch (Exception ex)
{
Console.WriteLine(MethodBase.GetCurrentMethod().Name + "/" + GetLineNumber(ex));
}
}
public static int GetLineNumber(Exception ex)
{
var lineNumber = 0;
const string lineSearch = ":line ";
var index = ex.StackTrace.LastIndexOf(lineSearch);
if (index != -1)
{
var lineNumberText = ex.StackTrace.Substring(index + lineSearch.Length);
if (int.TryParse(lineNumberText, out lineNumber))
{
}
}
return lineNumber;
}
}
}
Note: In the extract line method, we are fetching the top most exception. This comes in handy when we have a chain of exceptions in our stack trace.
I have to skip execution of the test case #bannerVerificationSMMDView only when the viewPort is Large
#Before
public void beforestartUp(Scenario scenario) throws IOException {
boolean runTest = true;
if (viewPort.contains("LARGE")) {
System.out.println("for Scenario " + scenario.getName() + " tagname are");
List<String> tags = (List<String>) scenario.getSourceTagNames();
for (String tagName : tags) {
if (tagName.contains("bannerVerificationLView"))
runTest = false;
}
try {
Assume.assumeTrue(runTest);
} catch (AssumptionViolatedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Not sure why, but exception is not getting caught
Throw a AssumptionViolatedException to skip the execution of scenario.
#Before(value="#bannerVerificationSMMDView")
public void before(Scenario scenario) {
if(viewPort.contains("LARGE"))
throw new AssumptionViolatedException("Skipping as view is LARGE");
}
If you are on cucumber version 3 plus, you can use a #BeforeStep annotation instead, keep everything else same. This will allow you to run any previous steps in the scenario and if condition is not met then skip the rest of the steps in the scenario
I'm trying create a generic Java Agent to instrument any Java application's methods.
I've followed this tutorial https://javapapers.com/core-java/java-instrumentation/ and created a java agent.
The java agent is supposed to look for a particular class ( I'm restricting it to one class now since it's not working for me)
Once the class is found, I'm using JavaAssist API to add a local variable to the beginning of each method and capture the current time. In the end of the method I'd like to simply print the time it took for the method to execute. (Pretty much following all the typical examples about Java agent.
I run my test application ( a web server using Vert.x ) with --javaagent flag pointing to the Java agent jar file I created ( the code is down below).
This works just fine for methods that either don't have return value and no parameters or return/take a primitive type.
However when a method is returning or taking a parameter that is an object from a another class (that has not been loaded yet I think) I get a CannotCompileException exception with the message that that class which is in the parameters list or in the return statement is not found.
For example the instrumentation for this method works:
#Override
public void start() throws Exception {
logger.debug("started thread {}", Thread.currentThread().getName());
for (int port : ports) {
HttpServer httpServer = getVertx().createHttpServer(httpServerOptions);
Router router = setupRoutes();
httpServer.requestHandler(router::accept);
logger.info("Listening on port {}", port);
httpServer.listen(port);
}
}
However for this method that returns io.vertx.ext.web.Router:
private Router setupRoutes() {
Router router = Router.router(getVertx());
router.get(STATUS_PATH).handler(this::statusHandler);
router.route().handler(BodyHandler.create());
router.post().handler(this::handleBidRequest);
router.put().handler(this::handleBidRequest);
router.get(SLEEP_CONTROLLER_PATH).handler(this::sleepControllerHandler);
return router;
}
I get an exception and the output of my java agent is :
Instrumenting method rubiconproject.com.WebServerVerticle.setupRoutes()
Could not instrument method setupRoutes error: cannot find io.vertx.ext.web.Router
This the code for my java agent:
import java.lang.instrument.Instrumentation;
import transformers.TimeMeasuringTransformer;
public class TimeCapturerAgent {
public static void premain(String agentArgs, Instrumentation inst) {
System.out.println(TimeCapturerAgent.class.getCanonicalName() + " is loaded...... ");
inst.addTransformer(new TimeMeasuringTransformer());
}}
package transformers;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.security.ProtectionDomain;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
public class TimeMeasuringTransformer implements ClassFileTransformer {
public TimeMeasuringTransformer() {
System.out.println("TimeMeasuringTransformer added ");
}
#Override
public byte[] transform(ClassLoader loader,
String className,
Class<?> classBeingRedefined,
ProtectionDomain protectionDomain,
byte[] classfileBuffer) throws IllegalClassFormatException {
if(className != null && className.contains("WebServerVerticle")) {
System.out.println("Instrumenting class " + className);
return modifyClass(classfileBuffer);
}
return null;
}
private byte[] modifyClass(byte[] originalClassfileBuffer) {
ClassPool classPool = ClassPool.getDefault();
CtClass compiledClass;
try {
compiledClass = classPool.makeClass(new ByteArrayInputStream(originalClassfileBuffer));
System.out.println("Created new compiled Class " + compiledClass.getName());
} catch (IOException e) {
e.printStackTrace();
return null;
}
instrumentMethods(compiledClass);
byte [] newClassByteCode = createNewClassByteArray(compiledClass);
compiledClass.detach();
return newClassByteCode;
}
private byte[] createNewClassByteArray(CtClass compiledClass) {
byte[] newClassByteArray = null;
try {
newClassByteArray = compiledClass.toBytecode();
} catch (IOException e) {
e.printStackTrace();
} catch (CannotCompileException e) {
e.printStackTrace();
} finally {
return newClassByteArray;
}
}
private void instrumentMethods(CtClass compiledClass) {
CtMethod[] methods = compiledClass.getDeclaredMethods();
System.out.println("Class has " + methods.length + " methods");
for (CtMethod method : methods) {
try {
System.out.println("Instrumenting method " + method.getLongName());
method.addLocalVariable("startTime", CtClass.longType);
method.insertBefore("startTime = System.nanoTime();");
method.insertAfter("System.out.println(\"Execution Duration "
+ "(nano sec): \"+ (System.nanoTime() - startTime) );");
} catch (CannotCompileException e) {
System.out.println("Could not instrument method " + method.getName()+" error: " + e.getMessage());
continue;
}
}
}}
I am using java 8 stream and I can not throw the exceptions inside the foreach of stream.
stream.forEach(m -> {
try {
if (isInitial) {
isInitial = false;
String outputName = new SimpleDateFormat(Constants.HMDBConstants.HMDB_SDF_FILE_NAME).format(new Date());
if (location.endsWith(Constants.LOCATION_SEPARATOR)) {
savedPath = location + outputName;
} else {
savedPath = location + Constants.LOCATION_SEPARATOR + outputName;
}
File output = new File(savedPath);
FileWriter fileWriter = null;
fileWriter = new FileWriter(output);
writer = new SDFWriter(fileWriter);
}
writer.write(m);
} catch (IOException e) {
throw new ChemIDException(e.getMessage(),e);
}
});
and this is my exception class
public class ChemIDException extends Exception {
public ChemIDException(String message, Exception e) {
super(message, e);
}
}
I am using loggers to log the errors in upper level. So I want to throw the exception to top. Thanks
Try extending RuntimeException instead. The method that is created to feed to the foreach does not have that type as throwable, so you need something that is runtime throwable.
WARNING: THIS IS PROBABLY NOT A VERY GOOD IDEA
But it will probably work.
Why are you using forEach, a method designed to process every element, when all you want to do, is to process the first element? Instead of realizing that forEach is the wrong method for the job (or that there are more methods in the Stream API than forEach), you are kludging this with an isInitial flag.
Just consider:
Optional<String> o = stream.findFirst();
if(o.isPresent()) try {
String outputName = new SimpleDateFormat(Constants.HMDBConstants.HMDB_SDF_FILE_NAME)
.format(new Date());
if (location.endsWith(Constants.LOCATION_SEPARATOR)) {
savedPath = location + outputName;
} else {
savedPath = location + Constants.LOCATION_SEPARATOR + outputName;
}
File output = new File(savedPath);
FileWriter fileWriter = null;
fileWriter = new FileWriter(output);
writer = new SDFWriter(fileWriter);
writer.write(o.get());
} catch (IOException e) {
throw new ChemIDException(e.getMessage(),e);
}
which has no issues with exception handling. This example assumes that the Stream’s element type is String. Otherwise, you have to adapt the Optional<String> type.
If, however, your isInitial flag is supposed to change more than once during the stream processing, you are definitely using the wrong tool for your job. You should have read and understood the “Stateless behaviors” and “Side-effects” sections of the Stream API documentation, as well as the “Non-interference” section, before using Streams. Just converting loops to forEach invocations on a Stream doesn’t improve the code.
I have a below action in a controller which throw HttpException with status code 404:
public async Task<ActionResult> Edit(int id)
{
Project proj = await _service.GetProjectById(id);
if( proj == null)
{
throw new HttpException(404, "Project not found.");
}
}
To test this scenario, I have written below test case where I am catching AggregationException and rethrowing InnerException which is expected as HttpException:
[TestMethod]
[ExpectedException(typeof(HttpException),"Project not found.")]
public void Edit_Project_Load_InCorrect_Value()
{
Task<ActionResult> task = _projectController.Edit(3);
try
{
ViewResult result = task.Result as ViewResult;
Assert.AreEqual("NotFound", result.ViewName, "Incorrect Page title");
}
catch (AggregateException ex)
{
throw ex.InnerException;
}
}
This test run succefully and return ExpectedException. I have two questions here:
Is this right approach for writing unit test or there is more
gracious way of testing it.
Is this possible to check in Unit Test
that user is getting correct error page( NotFound in this case).
There is a nicer way to test this. We wrote a class called AssertHelpers.cs that has this method in it. The reason this is nicer than ExpectedException is that ExpectedException does not actually verify it was thrown, it just allows the test to pass when it is thrown.
For example, if you change your 404 code to return 200 your test will not fail.
public static void RaisesException<TException>(Action dataFunction, string exceptionIdentifier = null)
{
bool threwException = false;
try
{
dataFunction();
}
catch (Exception e)
{
threwException = true;
Assert.IsInstanceOfType(e, typeof(TException));
if (exceptionIdentifier != null)
Assert.AreEqual(exceptionIdentifier, e.Message);
}
if (!threwException)
Assert.Fail("Expected action to raise exception with message: " + exceptionIdentifier);
}