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CITCON Asia-Pacific 2009

without comments

The location for CITCON Asia-Pacific 2009 has just been announced, and the winner is: Brisbane! Huzzah.

Written by Tom Adams

September 14th, 2008 at 4:45 pm

Posted in Agile,BDD,TDD

Tagged with

Instinct 0.1.9 Release

without comments

I’m happy to announce the release of Instinct 0.1.9. This is a maintenance release that also allowed me to introduce some new features such as custom lifecycles. Other tidbits include multiple specification failures reported, Scala examples, additional Functional Java matchers (List, Either, Option), Maven bundle and a seperate source JAR.

Downloads are available from the project site.

Here’s the full list of changes:

  • Core Features
    • Custom specification lifecycles can now be plugged in using the @Context annotation. This would allow for example, a Spring application context to be initialised and wired into each specification method allowing integration-style specifications using a Spring beans.
    • Multiple errors are now displayed when a specification fails with more than one exception.
  • Expectation API
    • Added fj.data.List matchers: expect.that(List.nil().cons(1)).isEqualTo(List.nil().cons(1))
    • Added fj.data.Option matchers: expect.that(Some(1)).isSome(1), expect.that(foo.bar()).isNone().
    • Added fj.data.Either matchers: expect.that(error()).isLeft(runtimeException), expect.that(foo.bar()).isRight(42).
  • Scala integration
    • Added Scala stack example, showing the use of Instinct under Scala to spec out Scala code.
  • Maven integration
    • Added Maven bundle to allow uploading to central Maven repository.
  • Packaging
    • Moved source code out of main jar into instinct-<version>-sources.jar (for Maven).
    • Moved javadoc into jar instead of zip instinct-<version>-javadoc.jar (for Maven).
  • Infrastructure
    • Upgraded to Functional Java 2.10.
    • Downgraded (again) to CGLib 2.1.3 (for Maven integration).
  • Bugs
    • (Issue 21) Expected exception try-catch should only wrap specs, not before and after.
    • (Issue 19) Throwing exception out of mocked code confused expected exception handling.
    • (Issue 40) Formatting of multiple exception report could be nicer.

Written by Tom Adams

August 8th, 2008 at 4:10 pm

Posted in BDD,Instinct,Java,Scala

Error handling with Either, or, Why Either rocks!

with 3 comments

Instinct, like most xUnit-like frameworks provides the ability to run methods, and have the status of those methods reported. In xUnit frameworks these methods are called tests, in Instinct they’re called specifications.

Specifications are ordinary instance methods that are marked in a way (naming convention or annotation) that tells Instinct to run them. Each specification has a lifecycle associated with it, where both the creator of the method (the developer specifying code) and the framework itself performs pre- and post-specification steps (Instinct tries to take away and simplify a lot of the drudgery involved in traditional testing).

Specifications have the following lifecycle (the default implementation can be overridden):

  1. The context class for the specification is created.
  2. The mockery is reset, all mocks now contain no expectations.
  3. Specification actors are auto-wired.
  4. Before specification methods are run.
  5. The specification is run.
  6. After specification methods are run.
  7. Mock expectations are verified.

Any step of this lifecycle can throw exceptions causing the specification to fail. For example a before specification method may throw a NullPointerException, or a specification may pass while a mock used in it may not have an expectation met.

The framework needs flexibility in choosing which parts of the lifecycle to run, which parts are important when executing the specification, what failures constitute stopping the run of a specification, etc.

Here’s the code we’re starting with:

private SpecificationResult runSpecification(final SpecificationMethod specificationMethod) {
  final long startTime = clock.getCurrentTime();
  try {
    final Class<?> contextClass = specificationMethod.getContextClass();
    final Object instance = invokeConstructor(contextClass);
    runSpecificationLifecycle(instance, specificationMethod);
    return createSpecResult(specificationMethod, SPECIFICATION_SUCCESS, startTime);
  } catch (Throwable exceptionThrown) {
    final SpecificationRunStatus status = new SpecificationRunFailureStatus(exceptionSanitiser.sanitise(exceptionThrown));
    return createSpecResult(specificationMethod, status, startTime);
  }
}

private void run(final Object contextInstance, final SpecificationMethod specificationMethod) {
  Mocker.reset();
  actorAutoWirer.autoWireFields(contextInstance);
  try {
    runMethods(contextInstance, specificationMethod.getBeforeSpecificationMethods());
    runSpecificationMethod(contextInstance, specificationMethod);
  } finally {
    try {
      runMethods(contextInstance, specificationMethod.getAfterSpecificationMethods());
    } finally {
      Mocker.verify();
    }
  }
}

This implementation of of the specification runner is overly simplistic. It runs everything within a large try-catch block, which means there’s no way to tell which part of the specification failed (before, spec, after, etc.). It also cannot collect up errors, so if an error occurs in a specification and a mock fails to verify, only the verification error is propagated. These are currently two of the highest priority user reported issues on Instinct.

Here’s my first attempt at isolating which part of the specification failed, each of the constants passed to fail define the location of the failure.

public SpecificationResult run(final SpecificationMethod specificationMethod) {
  try {
    final Class<?> contextClass = specificationMethod.getContextClass();
    final Object instance = invokeConstructor(contextClass);
    Mocker.reset();
    try {
      actorAutoWirer.autoWireFields(instance);
      try {
        runMethods(instance, specificationMethod.getBeforeSpecificationMethods());
        try {
          runSpecificationMethod(instance, specificationMethod);
          return result(specificationMethod, SPECIFICATION_SUCCESS);
        } catch (Throwable t) {
          return fail(specificationMethod, t, SPECIFICATION);
        } finally {
          try {
            try {
              runMethods(instance, specificationMethod.getAfterSpecificationMethods());
            } catch (Throwable t) {
              return fail(specificationMethod, t, AFTER_SPECIFICATION);
            }
          } finally {
            try {
              Mocker.verify();
            } catch (Throwable t) {
              return fail(specificationMethod, t, MOCK_VERIFICATION);
            }
          }
        }
      } catch (Throwable t) {
        return fail(specificationMethod, t, BEFORE_SPECIFICATION);
      }
    } catch (Throwable t) {
      return fail(specificationMethod, t, AUTO_WIRING);
    }
  } catch (Throwable t) {
      return fail(specificationMethod, t, CLASS_INITIALISATION);
  }
}

Obviously, this is very ugly, it’s also hard to reason about. But, as we now have the location of the failure we can make decisions as to whether we fail the specification, or not, so we’ve solved our first issue. But we haven’t made our second task any easier, we aren’t generally able to keep processing (we still validate mocks in the above code upon specification failure) and we don’t collect all the errors that occur.

And at about this time enters Either (in Scala):

The Either type represents a value of one of two possible types (a disjoint union). The data constructors; Left and Right represent the two possible values. The Either type is often used as an alternative to Option where Left represents failure (by convention) and Right is akin to Some.

Either can be used in place of conventional exception handling in Java, or, to wrap APIs that use conventional exception handling (a more thorough treatment of this issue is given in Lazy Error Handling in Java, Part 3: Throwing Away Throws). Here’s an example of the latter, using both Either and Option (discussed later).

public Either<Throwable, List<Field>> wireActors(final Object contextInstance) {
  try {
    return right(actorAutoWirer.autoWireFields(contextInstance));
  } catch (Throwable t) {
    return left(t);
  }
}

...

public Option<Throwable> verifyMocks() {
  try {
    Mocker.verify();
    return none();
  } catch (Throwable t) {
    return some(t);
  }
}

At a high level, the good thing about using Either is that your methods no longer lie; they don’t declare that they’ll return an Int, or, maybe, they’ll throw an exception, they come right out and say it: I’ll return either an exception or an Int. This is akin to conventional checked exceptions in Java (which Scala does away with), where a checked exception is used to represent a recoverable failure (enforced by the compiler) and an unchecked exception to represent an unrecoverable failure (not compiler enforced). Scala takes the correct approach here, it uses unchecked exceptions to represent the bottom value in non-terminating functions, and Either to represent recoverable failure.

Either is also much more flexible than exceptions, you can map across it, convert it into an option, add them into a container, and generally treat them like any other data structure [1].

So armed with this new knowledge, here’s the new specification lifecycle broken out from the runner itself (note, there are eleven steps in the lifecycle, including validation, however only these are exposed).

interface SpecificationLifecycle {
  <T> Either<Throwable, ContextClass> createContext(Class<T> contextClass);
  Option<Throwable> resetMockery();
  Either<Throwable, List<Field>> wireActors(Object contextInstance);
  Option<Throwable> runBeforeSpecificationMethods(
      Object contextInstance, List<LifecycleMethod> beforeSpecificationMethods);
  Option<Throwable> runSpecification(
      Object contextInstance, SpecificationMethod specificationMethod);
  Option<Throwable> runAfterSpecificationMethods(
      Object contextInstance, List<LifecycleMethod> afterSpecificationMethods);
  Option<Throwable> verifyMocks();
}

Now we need to make use of this in the specification runner, one step of which is determining the overall result, from the sequence of steps. Here’s my first attempt at this, using Functional Java’s Either to represent the result of each of the steps.

public <T extends Throwable> Either<List<T>, SpecificationResult> determineLifecycleResult(
    final Either<T, Unit> createContextResult,
    final Either<T, Unit> restMockeryResult,
    final Either<T, Unit> wireActorsResult,
    final Either<T, Unit> runBeforeSpecificationMethodsResult,
    final Either<T, SpecificationResult> runSpecificationResult,
    final Either<T, Unit> runAfterSpecificationMethodsResult,
    final Either<T, Unit> verifyMocksResult) {
  List<T> errors = List.nil();
  if (createContextResult.isLeft()) {
    errors = errors.cons(createContextResult.left().value());
  }
  if (restMockeryResult.isLeft()) {
    errors = errors.cons(restMockeryResult.left().value());
  }
  if (wireActorsResult.isLeft()) {
    errors = errors.cons(wireActorsResult.left().value());
  }
  if (runBeforeSpecificationMethodsResult.isLeft()) {
    errors = errors.cons(runBeforeSpecificationMethodsResult.left().value());
  }
  if (runSpecificationResult.isLeft()) {
    errors = errors.cons(runSpecificationResult.left().value());
  }
  if (runAfterSpecificationMethodsResult.isLeft()) {
    errors = errors.cons(runAfterSpecificationMethodsResult.left().value());
  }
  if (verifyMocksResult.isLeft()) {
    errors = errors.cons(verifyMocksResult.left().value());
  }
  return errors.isNotEmpty() ? Either.<List<T>, SpecificationResult>left(errors)
      : Either.<List<T>, SpecificationResult>right(runSpecificationResult.right().value());
}

All those ifs are a bit ugly (what happens when we have more?), and we’ve got a mutable list, surely we can do better? We’ve spotted a pattern here, and we could clean this up by folding across a list of results, pulling out the left of each Either, however Either does this for us, using Either.lefts() (it performs the fold for you).

Here’s the next cut, making use of a list of results and Either.left():

public <T extends Throwable> Either<List<Unit>, Unit> determineLifecycleResult(
    final List<Either<T, Unit>> allResults, final Either<T, Unit> specificationResult) {
  final List<T> errors = lefts(allResults);
  return errors.isEmpty() ?
      Either.<List<T>, Unit>right(specificationResult.right().value()) :
      Either.<List<T>, Unit>left(errors);
}

So what’s this doing? It takes a list of results and goes through each of the lefts (the errors) returning them as a list. As Either is a disjunction (we’ll have an error or a result, but not both), if any of the results contain an error on the left, our list will be non-empty, meaning our specification failed to run. In this case we return the errors on the left. If we have no errors (i.e. the list is empty) we return the real result on the right.

This code can be simplified further by using Option instead of Either. Option would allow us to place any exception into the some data constructor, the Unit we’re placing into Either becomes the none (we’re used to thinking of void as nothing in Java anyway). The only hassle comes if we want to treat the Option as an Either (say in the lefts call above), in that case we’d need to lift the Option into an Either.

Option<Throwable> option = ...
Either<Throwable, Unit> either = option.toEither(unit()).swap();

Option also allows use to pull each some out of a list of Options, in a similar way to how we pulled the lefts out of a list of Eithers.

List<Option<Throwable>> results = ...
List<Throwable> errors = somes(results);
Option<Throwable> overall = errors.isEmpty() ?
    Option.<Throwable>none() :
    some((Throwable) new AggregatingException(errors));

Given that we’ve now decoupled the lifecycle from the runner and we know have a better way of handling errors, here’s the pattern of the new runner code:

private SpecificationResult runLifecycle(final long startTime,
    final SpecificationLifecycle lifecycle, final SpecificationMethod specificationMethod) {
  ...
  List<Option<Throwable>> lifecycleStepErrors = nil();
  final Either<Throwable, ContextClass> createContextResult =
      lifecycle.createContext(specificationMethod.getContextClass());
  lifecycleStepErrors = lifecycleStepErrors.cons(createContextResult.left().toOption());
  if (createContextResult.isLeft()) {
    return fail(...);
  } else {
    final ContextClass contextClass = createContextResult.right().value();
    ...
    lifecycleStepErrors = lifecycleStepErrors.cons(contextValidationResult.left().toOption());
    if (contextValidationResult.isSome()) {
      return fail(...);
    } else {
      ...
      lifecycleStepErrors = lifecycleStepErrors.cons(...left().toOption());
      if (...isSome()) {
        return fail(...);
      } else {
        ...
        if (...isSome()) {
          return fail(...);
        } else {
          ...
          if (...isSome()) {
            return fail(...);
          } else {
            ...
            if (...isSome()) {
              return fail(...);
            } else {
              ...
              return determineResult(..., lifecycleStepErrors);
            }
          }
        }
      }
    }
  }
}

See the pattern there? Let’s see it in slow motion. Assume each of the lifecycle results is called a, b, c, etc.

if (a.isLeft()) {
  return fail()
} else {
  if (b.isLeft()) {
    return fail()
  } else {
    if (c.isLeft() {
    } else {
      ...
    }
  }
}

What we’re doing is binding through each lifecycle result, if we get an error, we fail fast, if we don’t, we execute the next step. There’s some other muck going on here too, we’re destructively updating the list of errors (lifecycleStepErrors), and the last few steps (run the specification, run after methods, verify mocks) are always executed, regardless of whether any fail. So how do we clean the code up? We anonymously bind through Either on the right, and sequence through the rest accumulating errors. What???

Here’s a simple example that contains eleven steps representative of running a specification. For the first eight (a through h), each step’s predecessor must succeed (i.e. we have at most one error). For the last three (i through k), we execute all of them regardless of whether they fail and accumulate the errors. We make use of the new Validation class in Functional Java (in version 2.9) to perform the last three steps (full source; this example has been further refined in the trunk).

class X {
  // The first sequence of steps...
  Either<Throwable, Unit> a;
  Either<Throwable, Unit> b;
  Either<Throwable, Unit> c;
  Either<Throwable, Unit> d;
  Either<Throwable, Unit> e;
  Either<Throwable, Unit> f;
  Either<Throwable, Unit> g;
  Either<Throwable, Unit> h;
  // The second sequence of steps...
  Either<Throwable, Unit> i;
  Either<Throwable, Unit> j;
  Either<Throwable, Unit> k;

  // Execute the first sequence of steps, fail on the first error.
  Either<Throwable, Unit> t1() {
    return a.left()
        .sequence(b).right()
        .sequence(c).right()
        .sequence(d).right()
        .sequence(e).right()
        .sequence(f).right()
        .sequence(g).right()
        .sequence(h);
  }

  // Execute the second sequence of steps, accumulate the errors.
  Option<NonEmptyList<Throwable>> t2() {
    return validation(t1()).nel().accumulate(
        Semigroup.<Throwable>nonEmptyListSemigroup(),
        Validation.<Throwable, Unit>validation(g).nel(),
        Validation.<Throwable, Unit>validation(h).nel(),
        Validation.<Throwable, Unit>validation(i).nel());
  }
}

Each of the fields in the above represents the result of executing a step in the specification lifecycle (including validation, which is beyond the SpecificationLifecycle itself), t1 represents the first eight steps, t2 the last three steps. t1 sequences through (anonymous bind) the result of each step, failing if any individual step fails. t2 executes [2] each step, continuing execution of the remaining steps if any step fails, and accumulates the errors.

Remember that this is what t1 looked like originally:

if (a.isLeft()) {
  return fail()
} else {
  if (b.isLeft()) {
    return fail()
  } else {
    if (c.isLeft() {
    } else {
      ...
    }
  }
}

Some simpler examples may make the binding clearer; consider Scala’s Option (used here for brevity). We can bind through Option using orElse:

scala> Some(7).orElse(Some(8))
res0: Option[Int] = Some(7)

Here we execute Some(7), if that fails (i.e. returns none), we execute Some(8). As we see, the result is Some(7). Let’s take a failure case:

scala> None.orElse(Some(8))
res1: Option[Int] = Some(8)

We execute None, if that fails (i.e. returns none), which it does, we execute Some(8). As we see, the result is Some(8).

Taking it back to our simple Java example, we evaluate the result of step a [2], if it fails, we return the failure, if it succeeds, we evaluate step b, and so on. This is the same logic we saw in the nested if-else blocks earlier. If any of the first eight steps fail, we get back either one error (from t1), if any of the last three steps fail, we get back at most 3 errors (from t2)

If we apply this pattern to our specification runner code, we get the following:

private SpecificationResult runLifecycle(final long startTime, final SpecificationLifecycle lifecycle,
    final SpecificationMethod specificationMethod) {
  final Either<Throwable, ContextClass> createContext = lifecycle.createContext(specificationMethod.getContextClass());
  if (createContext.isLeft()) {
    return fail(startTime, specificationMethod, createContext.left().value(), false);
  } else {
    final ContextClass contextClass = createContext.right().value();
    final Either<Throwable, Unit> validation = validateSpecification(contextClass, specificationMethod);
    if (validation.isLeft()) {
      return fail(startTime, specificationMethod, validation.left().value(), false);
    } else {
      return runSpecification(startTime, lifecycle, contextClass, specificationMethod);
    }
  }
}

That looks bit better, but where’s the complexity gone? OK, here it is…

private SpecificationResult runSpecification(final long startTime, final SpecificationLifecycle lifecycle, final ContextClass contextClass,
    final SpecificationMethod specificationMethod) {
  final Object contextInstance = constructorInvoker.invokeNullaryConstructor(contextClass.getType());
  final Validation<Throwable, Unit> preSpecificationSteps =
      validate(resetMocks().f(lifecycle)).sequence(validation(wireActors().f(lifecycle, contextInstance)))
          .sequence(validate(befores().f(lifecycle, contextInstance, contextClass.getBeforeSpecificationMethods())));
  if (preSpecificationSteps.isFail()) {
    return fail(startTime, specificationMethod, preSpecificationSteps.fail(), Option.<Throwable>none());
  } else {
    final Option<Throwable> specification = specification().f(lifecycle, contextInstance, specificationMethod);
    final Option<NonEmptyList<Throwable>> result = preSpecificationSteps.nel().accumulate(throwables(), validate(specification).nel(),
        validate(afters().f(lifecycle, contextInstance, contextClass.getAfterSpecificationMethods())).nel(),
        validate(verifyMocks().f(lifecycle)).nel());
    if (result.isSome()) {
      return fail(startTime, specificationMethod, result.some().toList(), specification);
    } else {
      return success(startTime, specificationMethod);
    }
  }
}

Here’s the complete old and new versions of the code if you’re so inclined…

This code combined with the extracted lifecycle class is functionally equivalent to the first snippet of code I presented above. It may look verbose (it would be much simpler in Scala for example), but an interesting thing came out of it; it made explicit a bunch of places where I wasn’t handling exceptions correctly. It forced me to make a decision as to what to do in each case, so I got a much finer grained exception handling mechanism. Of course, I could get the same using try-catch (arguably more verbose), and I can choose to ignore left results (errors) if I want. The other thing it highlights is Java’s woeful generics implementation [3].

When I started down this path to error handling I had two objectives (two reported issues to resolve); to allow the runner of a specification to know which parts failed (this gives the flexibility to allow before specs to error and not be reported as expected exceptions) and to return all the errors resulting from running a specification. I didn’t initially intend to go down this path, however after talking in the office, decided that there was a better way to handle this than nested try-catch blocks. The resulting code is smaller (even using Java), simpler and much more flexible than the traditional Java method of exception handling. A win all round. There are some downsides however, firstly, the verbosity of Java’s typing leads to a mess of Either<Throwable, Unit> and this method of error handling will be foreign to a lot of Java developers today.

Epilogue

The concept of sequencing while accumulating errors has been generalised in Functional Java (from version 2.9) as validation, here is an example of it in action. Scalaz contains a similar concept, though this uses applicative functors over higher kinds (something which Java’s type system does not support), here’s a small example of its use.

Footnotes

  1. There’s no reason why you couldn’t catch an exception and wrap it up in a list, or your own data structure instead of using Either, but most of the work is already done for us (i.e. useful functions across Either have been defined) and it’s a useful convention.
  2. Java is strict, so we don’t get the benefit of lazy evaluation in this case, but could emulate it with a function.
  3. The problems I’ve encountered mainly have to do with covariance in type parameters and differences between the way methods returning types are treated vs. local variables (see the bottom of StandardSpecificationLifecycle for details).

Written by Tom Adams

August 6th, 2008 at 2:27 pm

Testing in Scala using a Java tool

without comments

My first post on Graceless Failures, a blog about adventures on the path to learning Scala:

Scala, like a lot of other languages these days, ships with a unit testing framework – SUnit – built in. Many other Scala specific “testing” frameworks have sprung up in recent times that contain similar or vastly different feature sets to the traditional xUnit tools. These include Reductio, ScalaCheck, Specs, ScalaTest, and SUnit (built into the Scala distribution).

And as Scala is “just Java” you can also use Java frameworks such as JUnit and TestNG. Having only used Reductio, I can’t vouch for any others, though ScalaTest is getting good airplay on Artima and Specs seems to have the Scala BDD mindshare.

These tools can be loosely categorised as traditional unit testing tools, ala xUnit, or automated specification testing tools, ala QuickCheck. Reductio and ScalaCheck are incarnations of automated specification testing, while Specs, ScalaTest and SUnit are more your traditional xUnit frameworks.

However, I’m not to write about any of these frameworks, instead, I’m going to write about Instinct, a Java BDD framework that I’ve been developing for around 18 months, and for which I’ve recently started to add specific support for Scala into the codebase. Good fodder for blog posts!

Continue reading Testing in Scala using a Java tool.

Written by Tom Adams

July 29th, 2008 at 9:43 am

Instinct 0.1.8 Release

without comments

I’m happy to announce the release of Instinct 0.1.8. This is a maintenance release resolving some minor bugs and packaging issues from the 0.1.7 release.

Chris has been spiking some Spring integration and needed a way to turn off detection of specs based on naming conventions and annotations so this is in this release also. Currently it’s only available via the @Context annotation, so you’ll have to annotate each class you want to override the default behaviour on. If there’s enough interest in this, I’ll add a way to change this globally.

Downloads are available from the project site.

Here’s the full list of changes:

  • Core Features
    • Custom specification, before specification and after specification annotations and naming conventions can be provided via the Context annotation. This can also be used to turn off naming convention-based detection (using NoNamingConvention).
  • Infrastructure
    • Upgraded to: Functional Java 2.8.
  • Bugs
    • (Issue 36) Abstract classes are being run as a result of specification runner refactoring.
    • (Issue 37) Expected exceptions are being printed to console in Ant runner even though spec passes.
    • (Issue 38) Functional java jar is not included in release zip.

Written by Tom Adams

July 26th, 2008 at 2:22 pm

Posted in BDD,Instinct,Java

Instinct 0.1.7 Release

without comments

I’m happy to announce the release of Instinct 0.1.7. This is mainly a maintenance release, and includes the removal of in progress specification state, runners now emit pending reason, added Functional Java based matchers, upgrades to dependencies, Ant 1.7.1, CGLib 2.2, jMock 2.5.0 and Objenesis 1.1 and an internal re-write of specification runners.

Note that the upgrade to jMock 2.5.0 may cause issues with current mocks, you should consult the jMock documentation and release notes if you run into trouble. I’ve also added a new dependency on Functional Java, which is used both internally and can be used from two new matchers.

Downloads are available from the project site.

Here’s the full list of changes:

  • Core Features
    • Removed in progress specification state, use pending instead.
    • All runners now emit pending specification reason.
  • Expectation API
    • Added function matcher, e.g. expect.that(list).doesNotContain({int i => i > 3} (based on Functional Java’s fj.F).
    • Added fj.data.List matcher.
  • Infrastructure
    • Added dependency on Functional Java, used both internally and for use in expectation API.
    • Continued clean up of specification running code.
    • Upgraded to: Ant 1.7.1, CGLib 2.2, jMock 2.5.0 and Objenesis 1.1.
  • Bugs
    • (Issue 11) It would be nice not to have to depend on jmock when writing a BDD-style test involving no mocks.

Written by Tom Adams

July 25th, 2008 at 8:30 am

Posted in BDD,Functional,Instinct

Tagged with

Microsoft release Pex

without comments

My googlebot just informed me that Microsoft has released Pex, which “generates Unit Tests from hand-written Parameterized Unit Tests through Automated Exploratory Testing based on Dynamic Symbolic Execution” (what a mouthful!). At first glance, it looks very similar to JUnit’s Theories and Tony’s Reductio. The difference appears to be that Pex generates the tests statically (don’t know how long they hang around) rather than dynamically like Reductio and JUnit. Ah, QuickCheck for Microsofties…

Written by Tom Adams

June 3rd, 2008 at 2:25 pm

Instinct 0.1.6 Release

without comments

I’m happy to announce the release of Instinct 0.1.6. Thanks to all our new users and especially to the guys at VLC & SAP who’ve helped us apply Instinct in anger, and Sanjiv, who’s come on board with development.

Downloads are available from the project site.

This release includes a raft of updates, most notably auto-creation of specification doubles (mocks, stubs & dummies), automatic reset and verification of mocks, a cleanup of the state-based expectation API, fixes for Eclipse JUnit integration, custom classpath support in the Ant task and inherited contexts.

Here’s the full list of updates:

Core

  • Remove the need for @Context annotation.
  • Automatic creation of specification doubles: mocks, stubs and dummies.
  • Automatic reset and verification of mocks.
  • @BeforeSpecification?, @AfterSpecification?, @Specifications (and naming convention equivalents) can be used across base and subclasses.

Expectation API

  • Make expectations more like natural language. eg. isEqualTo(), doesNotEqual(), etc. Existing code using equalTo(), etc. will need to be updated.
  • Collection checkers: hasTheSameContentAs(Collection) and hasTheSameContentAs(E…). These only check content and not the order of elements.
  • Ensure all “collection” classes (Array, Map, Set, List, String, SharSequence?) have similar size checkers available.
  • Added file checker
  • Better error messages for hasBeanProperty and hasBeanPropertyWithValue.

JUnit integration

  • Fix Eclipse unrooted context.

Ant integration

  • Support for custom classpath.
  • Quiet specification result formatting (only shows errors and pending specs).
  • Use correct project logging level for errors, etc.

jMock integration

  • Support states: Mockery.states(String).

Infrastructure

  • Removed reliance on Boost, transferred all relevant Boost classes locally.
  • jMock 2.4.
  • Downgraded to CGLib 2.1.3 (for Maven integration).

Bugs

  • Miscellaneous NullPointerExceptions? and null related problems in state expectation API.
  • (defect-3) IterableChecker? should have a containsOnly method or something.
  • (defect-8) @BeforeSpecification? does not run if implemented in an abstract base class.
  • (defect-20) CEclipse Junit4 InstinctRunner? shows tests under the “Unrooted Tests” node.
  • (defect-22) Context treeview shows baseclass and subclass when only subclass is run.
  • (defect-23) Overridden specifications run twice.

Written by Tom Adams

December 14th, 2007 at 4:57 pm

Posted in Agile,BDD,Instinct,Java,TDD

Better Testing Through Behaviour

with 3 comments

Just finished my talk on Better Testing Through Behaviour at OSDC 2007. All in all it went pretty well.

The presentation is available as is the paper.

Chris sent me some pictures of my talk, here’s one.

Tom at OSDC 2007

There’s been some posts (good and indifferent) resulting from the talk:

And for those interested, the slides for OSDC 2007 are available on SlideShare, photos on flickr.

Written by Tom Adams

November 27th, 2007 at 1:46 pm

Instinct 0.1.5 Release

without comments

I’m happy to announce the release of Instinct 0.1.5. This release includes a raft of updates, most notable a behaviour expectation API (using jMock 2) and JUnit 4 integration. Here’s the full list of new stuff:

Core

  • Initial cut of pending specifications (doesn’t report correctly in JUnit).
  • Added marking of specifications with naming conventions.

Expectation API

  • Behavioural expectation API (i.e. mocking).
  • Expected exception (simple version, encoded in specification annotation).
  • Add regular expression checking to string checker.
  • Add empty checks to array checker.

Integration

  • Added JUnit 4 runner, with @ContextClasses annotation.
  • Moved old mocking code to jMock 2, removed jMock 1.2 dependency.

Properties

  • Prototype QuickCheck style properties API (like Popper/JUnit 4 Theories).

Bugs

  • Fixed Issue 4 – Add newlines between context output in brief runner.
  • Fixed concurrent modification issue with the JUnit runner.

Misc

  • Upgraded to jMock 2.2.
  • Upgraded to JUnit 4.4.

Written by Tom Adams

October 17th, 2007 at 9:28 pm

Posted in Agile,BDD,Instinct,Java,TDD