How to cover exceptions in Visual Studio Code Coverage - exception

I am new to code-coverage, and I am trying to get my unit tests to cover %100 of my code.
My first question is, is this possible/feasible?
My second, more specific question is, I have the following method:
/// <summary>
/// Clears frames, control groups, display groups
/// </summary>
public bool Clear()
{
try
{
this.Frames.Clear();
this.ControlGroups.Clear();
this.DisplayGroups.Clear();
return true;
}
catch (Exception ex)
{
Milltown.MTCore.mtException mtEx = new Milltown.MTCore.mtException((int)PFExceptions.Exception_Hidden_FuctionLevel, ex,
PFCommonVariables.ApplicationPlatform, PFCommonVariables.ApplicationDataSource, "PFSystem:Clear");
return false;
}
}
My unit test for this method is:
//System Clear Test
Assert.IsTrue(MySystem.Clear());
Assert.AreEqual(0,MySystem.Frames.Count);
Assert.AreEqual(0,MySystem.ControlGroups.Count);
Assert.AreEqual(0, MySystem.DisplayGroups.Count);
Code coverage shows that I am covering the lines inside the try block, but not the catch block. How can I cover the code in catch blocks?

Improving your coverage is a good goal. Don't get too focused on the 100% number: it can be very misleading. More coverage is better than less, but even at 100%, you could be missing many aspects of your code (see http://nedbatchelder.com/blog/200710/flaws_in_coverage_measurement.html for examples in Python). And the last 5% of coverage may not tell you as much as you would like.
As for your exceptions, you'll need a way to force an exception to be thrown from one of your methods. A common way to do this is to mock out the implementation so you can decide what the sub-objects will actually do during the test, without being tied to a particular implementation.

It is possible, it is feasible. It is also very hard to accomplish, and not everyone is sure that the benefits outweigh the costs.
In regards to achieving your specific goal - look at the ExpectedExceptionAttribute, and in your test setup the objects to throw these exceptions.

Related

How to mock a CQ5 Page object containing a cq5 tag

I have a method on which I'd like to run a JUnit test. I'm mocking the cq5 page using JMockit.
My test method looks like this
#Mocked
Page page;
#Mocked
PageManager pageManager;
Tag testTag = pageManager.createTag("someID","someTitle","someDescription");//i've left out the try catch for brevety
System.out.println(testTag.getTitle()); // always null here
public void testSomeMethod() {
new Expectations() {
// variables declared here are mocked by default
{
page.getProperties();
propertyMap.put("cq:tags", testTag);
returns(new ValueMapDecorator(propertyMap));
}
};
String propertyValue = methodToBeTested(page);
Assert.assertEquals(propertyValue, "someTitle");
}
And the actual method to be tested does this :-
public static String getTopic(Page page) {
String topic = null;
Tag[] tags = page.getTags();
System.out.println(tags.size()); // returns 0 when I run the test.
for (int i = 0; i < tags.length; i++) {
Tag tag = tags[i];
topic = tag.getTitle();
}
}
return topic;
}
This always returns null when I run the test; however the method to be tested works correctly in the real scenario.
I suspect I'm not setting/mocking PageManager correctly, and consequently, my testTag is null
How do I mock this correctly to get the output I'm looking for?
You're getting to this testing from the wrong side. The way mocks (usually - I've never worked with jmockit specifically) work is, you create a blank object that acts as an impostor. This impostor is not a true PageManager - it only acts as one, and introduces himself as one whenever asked. When someone asks that impostor to do something (like calling it's method), the impostor does not know what to do, so it does nothing and returns null. However, you can tell the impostor how to behave in certain situations. Namely, you can tell it what to do when a method is called.
In your case, you don't need to create actual tags to test that method - you only need to mock a page object that, when asked for it's tags, will return an array containing a mocked tag which, in turn, when asked for it's title, will respond with the title you actually want to use in your test.
I don't know jmockit, so I cannot provide any code snippet. This, however, is a general question not strictly connected to CQ5/AEM
You may not be able to find any 'setter' methods for all objects you are trying to mock and this is anyways not the correct approach to mock.
The best way as mentioned by is to use mocked pages. You can use the Expectations class (mockit.Expectations) to mock the values to be returned by certain methods in the object.
See this example of mocking a 'SlingHttpServletRequest' object in a MockedClass class.
#Test
public void testMethod(#Mocked final SlingHttpServletRequest request){
String indicator ;
new Expectations() {
{
request.getParameter("archive");
returns("true");
}
};
indicator = OriginalClass.originalMethod(request);
Assert.assertEquals(indicator, "true");
}
In a similar way, you can mock other objects and their desired values.
I have answered the same question here: https://forums.adobe.com/thread/2536290
I ran into the same issue. in order to resolve Tags, they must exists under /content/cq:tags/your/tag or /etc/tags (legacy).
The Page#getTags implementation makes a call to TagManager#getTags which in turn tries to resolve the actual tag resource in the repo. Since you are testing in an AEM context, you have to load these tags in the appropriate location for the MockTagManager to resolve them.
What this means is that you need to load your tags into the AEM test context just like you've loaded your resources (via json).
Take a look at the aem-mock TagManager impl here: wcm-io-testing/MockTagManager.java at develop · wcm-io/wcm-io-testing · GitHub start with the resolve method and debug your way to figure out where you need to add those tags.

How to use contents = to add to a Scala Panel?

Sorry this must be a very silly question.. but everywhere I've been seeing Scala code examples where you just do
contents+= on a BoxPanel or some layout Panel. I figured because they have contents as mutable.buffer so you can just add and remove components.
But how do you add a component to Scala Panel? It accepts a seq so do you have to give it a list or something? I know you can just call peer.add but I want to see how Scala code does it. :)
For example contents = new Button {} isn't working.
Sorry for this simple question I'm very new to Scala..
EDIT:
Thanks for the replies. My question now though becomes.. can you ever just have a class extending Panel? Would you be able to set contents for it at all? Or is it never done and everyone always just uses the Panels associated with a layout manager?
The Panel class itself is abstract, meaning it can't be instantiated directly, and is intended as a "base" for concrete implementations of panels.
It doesn't seem to have a "common" method for adding components probably because each subclass implements its own, sometimes mutually incompatible custom one:
BoxPanel, as you've noted, has a settable Buffer,
FlowPanel seems to mandate adding components as constructor arguments,
GridBagLayout and some others implement addition via the layout Map,
etc.
As you might see from the above examples, it would be hard to specify what a general "add" method would mean in all of those cases.
EDIT in response: of course you can, there's nothing stopping you from subclassing a Panel yourself and override the contents method, e.g.:
val myPanel = new Panel() {
private val myContents = (new Content += new Button())
override def contents = myContents
}
You can also use Panel as a type parameter for your methods that process panels in a general way, etc. It's just that you can't have an instance that's just a Panel, because, again, the class is abstract, so you can't instantiate it.
Note that this is not unique to Scala, if JPanel was abstract in Java (like Component is) the outcome would be the same.
I want to see how Scala code does it.
https://github.com/scala/scala-swing/blob/v1.0.0-RC2/src/main/scala/scala/swing/Container.scala#L35
I, too, practiced on some Swing code when I first learned some Scala.
Here is a Panel component that renders itself as a simple game grid:
https://github.com/som-snytt/House-of-Mirrors-Fork/blob/act/src/main/scala/hom/LightBox.scala#L286
To see how the Scala and Swing pieces fit together, see SuperMixin:
https://github.com/scala/scala-swing/blob/v1.0.0-RC2/src/main/scala/scala/swing/Component.scala#L51
Assembly:
https://github.com/som-snytt/House-of-Mirrors-Fork/blob/act/src/main/scala/hom/HouseOfMirrors.scala#L18
This is what you asked about directly:
https://github.com/som-snytt/House-of-Mirrors-Fork/blob/act/src/main/scala/hom/HouseOfMirrors.scala#L45
If you have a button:
val button=new Button{
text="Click me!"
}
or
val label=new Label{
text="Look, i'm a label!"
}
or
object myField extends TextField{ columns=2 }
then you just use:
contents=new BoxPanel(Orientation.Vertical){
contents+=button
border=Swing.EmptyBorder(10,20,10,20)
}
or in a more simpler form:
contents=new FlowPanel(){
contents+=new Label("This is my button:")
contents+=new Button("Click me!")
border=Swing.EmptyBorder(10,20,10,20)
}

Flashpunk. Ways of adding entity to the World

Okay when I was going through different resources on Flashpunk I found three ways of adding entities to the world:
add(new Entity(10, 10));
//***************
var _entity:Entity;
//In constructor:
_entity = new Entity(10,10);
add(_entity);
//***************
FP.world.add(new Entity(10,10));
So my question is which one should I use and when.
Thank you.
add(new Entity(10, 10));
This will only work in whichever context add() is defined. I haven't used this specific library, but assuming that will be in a class called something similar to World and anything that inherits from it.
var entity:Entity = new Entity(10, 10);
add(entity);
This just breaks up the first example into two lines. It will also let you refer to that specific Entity before and after adding it to the world, whereas in the other example you have no way to reference the Entity you added.
FP.world.add(new Entity(10,10));
Here I'm assuming there's a class FP with the static property world representing a current relevant instance of the World. It does the same thing as the first example except that you can do this in any context. I would avoid using this; you'll find yourself using it as an excuse to add things to the world from unexpected locations in your code, leading to reduced code readability, frustration and a much harder debugging experience.
My preference is example 2. It's more readable, it suggests that you're using add within an appropriate context, and it lets you make changes to the Entity that you create:
var entity:Entity = new Entity();
entity.property = newValue;
add(entity);

Naming member functions/methods with a single underscore, good style or bad?

In some languages where you cannot override the () operator, I have seen methods with a single underscore, usually for 'helper' classes. Something likes this:
class D10
{
public function _()
{
return rand(1,10);
}
}
Is it better to have the function called Roll()? Is a underscore fine? After all, there is only one function, and it removes the need to look up the name of the class.
Any thoughts?
I would say it is a bad style. You can not infer behaviour from the name of the function if it simply an underscore.
In order to know what it does you need to read the code, or documentation.
(On a side note, I don't think D10 is a good name for a class either).
I guess it's a matter of taste. But I don't like it.
I believe having full self-explanatory names is always a better practice.
You won't save much time using only one keystroke to call your function but you'll likely loose more time remembering what it does afterwards.
But again, it is very subjective.
It may be legal, and whoever you're working with might not mind (even more so if you're working alone) but if it were me it would make me crazy. Spelling out D10.roll() doesn't take up much of your time, and it makes your code that much easier to follow since the name is self-explanatory.
The bottom line, though, is that elegance is in the eye of the beholder; if everyone who's working on your code agrees that that's a simple and clear identifier, nobody is going to stop you.
To me, this is quite obviously bad style.
Method names are names, and are supposed to be descriptive. They're not "proper names" like you have for people*, places and so on, they're names that describe the actions taken by the code contained within.
* Although of course many names for people were almost literally descriptive originally, but that's not generally the indended use nowadays.
I don't think the structure is optimal to begin with. I would simply do this:
class Dice
{
public int D10()
{
return rand(1,10);
}
public int D6()
{
return rand(1,6);
}
// And so on...
}
Then it will be made clear that we're actually taking about dice here and we don't have to create one class for every possible dice.
If you really need to abstract away what dice you're using, I hope that you're using a language that handle functions as first class objects, in which case you would do this:
void RussianRoulette(SOMEFUNCTIONSIGNATURE dice)
{
if (dice() == 1)
print "BANG";
else
print "click";
}
RussionRoulette(Dice.D6); // Regular russian roulette
RussionRoulette(Dice.D100); // For the faint of heart
RussionRoulette(Dice.D1); // Die! :)

Stylistic Question: Use of White Space

I have a particularly stupid insecurity about the aesthetics of my code... my use of white space is, frankly, awkward. My code looks like a geek dancing; not quite frightening, but awkward enough that you feel bad staring, yet can't look away.
I'm just never sure when I should leave a blank line or use an end of line comment instead of an above line comment. I prefer to comment above my code, but sometimes it seems strange to break the flow for a three word comment. Sometimes throwing an empty line before and after a block of code is like putting a speed bump in an otherwise smooth section of code. For instance, in a nested loop separating a three or four line block of code in the center almost nullifies the visual effect of indentation (I've noticed K&R bracers are less prone to this problem than Allman/BSD/GNU styles).
My personal preference is dense code with very few "speed bumps" except between functions/methods/comment blocks. For tricky sections of code, I like to leave a large comment block telling you what I'm about to do and why, followed by a few 'marker' comments in that code section. Unfortunately, I've found that some other people generally enjoy generous vertical white space. On one hand I could have a higher information density that some others don't think flows very well, and on the other hand I could have a better flowing code base at the cost of a lower signal to noise ratio.
I know this is such a petty, stupid thing, but it's something I really want to work on as I improve the rest of my skill set.
Would anyone be willing to offer some hints? What do you consider to be well flowing code and where is it appropriate to use vertical white space? Any thoughts on end of line commenting for two or three words comments?
Thanks!
P.S.
Here's a method from a code base I've been working on. Not my best, but not my worst by far.
/**
* TODO Clean this up a bit. Nothing glaringly wrong, just a little messy.
* Packs all of the Options, correctly ordered, in a CommandThread for executing.
*/
public CommandThread[] generateCommands() throws Exception
{
OptionConstants[] notRegular = {OptionConstants.bucket, OptionConstants.fileLocation, OptionConstants.test, OptionConstants.executable, OptionConstants.mountLocation};
ArrayList<Option> nonRegularOptions = new ArrayList<Option>();
CommandLine cLine = new CommandLine(getValue(OptionConstants.executable));
for (OptionConstants constant : notRegular)
nonRegularOptions.add(getOption(constant));
// --test must be first
cLine.addOption(getOption(OptionConstants.test));
// and the regular options...
Option option;
for (OptionBox optionBox : optionBoxes.values())
{
option = optionBox.getOption();
if (!nonRegularOptions.contains(option))
cLine.addOption(option);
}
// bucket and fileLocation must be last
cLine.addOption(getOption(OptionConstants.bucket));
cLine.addOption(getOption(OptionConstants.fileLocation));
// Create, setup and deploy the CommandThread
GUIInteractiveCommand command = new GUIInteractiveCommand(cLine, console);
command.addComponentsToEnable(enableOnConnect);
command.addComponentsToDisable(disableOnConnect);
if (!getValue(OptionConstants.mountLocation).equals(""))
command.addComponentToEnable(mountButton);
// Piggy-back a Thread to start a StatReader if the call succeeds.
class PiggyBack extends Command
{
Configuration config = new Configuration("piggyBack");
OptionConstants fileLocation = OptionConstants.fileLocation;
OptionConstants statsFilename = OptionConstants.statsFilename;
OptionConstants mountLocation = OptionConstants.mountLocation;
PiggyBack()
{
config.put(OptionConstants.fileLocation, getOption(fileLocation));
config.put(OptionConstants.statsFilename, getOption(statsFilename));
}
#Override
public void doPostRunWork()
{
if (retVal == 0)
{
// TODO move this to the s3fronterSet or mounts or something. Take advantage of PiggyBack's scope.
connected = true;
statReader = new StatReader(eventHandler, config);
if (getValue(mountLocation).equals(""))
{
OptionBox optBox = getOptionBox(mountLocation);
optBox.getOption().setRequired(true);
optBox.requestFocusInWindow();
}
// UGLY HACK... Send a 'ps aux' to grab the parent PID.
setNextLink(new PSCommand(getValue(fileLocation), null));
fireNextLink();
}
}
}
PiggyBack piggyBack = new PiggyBack();
piggyBack.setConsole(console);
command.setNextLink(piggyBack);
return new CommandThread[]{command};
}
It doesn't matter.
1) Develop a style that is your own. Whatever it is that you find easiest and most comfortable, do it. Try to be as consistent as you can, but don't become a slave to consistency. Shoot for about 90%.
2) When you're modifying another developer's code, or working on a group project, use the stylistic conventions that exist in the codebase or that have been laid out in the style guide. Don't complain about it. If you are in a position to define the style, present your preferences but be willing to compromise.
If you follow both of those you'll be all set. Think of it as speaking the same language in two different ways. For example: speaking differently around your friends than you do with your grandfather.
It's not petty to make pretty code. When I write something I'm really proud of, I can usually take a step back, look at an entire method or class, and realize exactly what it does at a glance - even months later. Aesthetics play a part in that, though not as large of a part as good design. Also, realize you can't always write pretty code, (untyped ADO.NET anyone?) but when you can, please do.
Unfortunately, at this higher level at least, I'm not sure there are any hard rules you can adhere to to always produce aesthetically pleasing code. One piece of advice I can offer is to simply read code. Lots of it. In many different frameworks and languages.
I like to break up logical "phrases" of code with white space. This helps others easily visualize the logic in the the method - or remind me when I go back and look at old code. For example, I prefer
reader.MoveToContent();
if( reader.Name != "Limit" )
return false;
string type = reader.GetAttribute( "type" );
if( type == null )
throw new SecureLicenseException( "E_MissingXmlAttribute" );
if( String.Compare( type, GetLimitName(), false ) != 0 )
throw new SecureLicenseException( "E_LimitValueMismatch", type, "type" );
instead of
reader.MoveToContent();
if( reader.Name != "Limit" )
return false;
string type = reader.GetAttribute( "type" );
if( type == null )
throw new SecureLicenseException( "E_MissingXmlAttribute" );
if( String.Compare( type, GetLimitName(), false ) != 0 )
throw new SecureLicenseException( "E_LimitValueMismatch", type, "type" );
The same break can almost be accomplished with braces but I find that actually adds visual noise and reduces the amount of code that can be visually consumed simultaneously.
Commens on code line
As for comments at the end of the line - almost never. The're not really bad, just easy to miss when scanning through code. And they clutter up the line taking away from the code making it harder to read. Our brains are already wired to grok line by line. When the comment is at the end of the line we have to split the line into two concrete concepts - code and comment. I say if it's important enough to comment on, put it on the line proceeding the code.
That being said, I do find one or two line hint comments about the meaning of a specific value are sometimes OK.
I find code with very little whitespace hard to read and navigate in, since I need to actually read the code to find logical structure in it. Clever use of whitespace to separate logical parts in functions can increase the ease of understanding the code, not only for the author but also for others.
Keep in mind that if you are working in an environment where your code is likely to be maintained by others, they will have spent the majority of their time looking at code that was not written by you. If your style distinctly differs from what they are used to seeing, your smooth code may be a speed bump for them.
I minimize white space. I put the main comment block above the code block and Additional end of line comments on the Stuff that may not be obvious to another dveloper. I think you are doing that already
My preferred style is probably anathema to most developers, but I will add occasional blank lines to separate what seem like appropriate 'paragraphs' of code. It works for me, nobody has complained during code reviews (yet!), but I can imagine that it might seem arbitrary to others. If other people don't like it I'll probably stop.
The most important thing to remember is that when you join an existing code base (as you almost always will in your professional career) you need to adhere to the code style guide dictated by the project.
Many developers, when starting a project afresh, choose to use a style based on the Linux kernel coding-style document. The latest version of that doc can be viewed at http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/CodingStyle;h=8bb37237ebd25b19759cc47874c63155406ea28f;hb=HEAD.
Likewise many maintainers insist that you use Checkpatch before submitting changes to version control. You can see the latest version that ships with the Linux kernel in same tree I linked to above at scripts/checkpatch.pl (I would link to it but I'm new and can only post one hyperlink per answer).
While Checkpatch is not specifically related to your question about whitespace usage, it will certainly help you eliminate trailing whitespace, spaces before tabs, etc.
Code Complete, by Steve McConnell (available in the usual locations) is my bible on this sort of thing. It has a whole chapter on layout and style that is just excellent. The whole book is just chock full of useful and practical advice.
I use exactly the same amount of whitespace as you :) Whitespace before methods, before comment blocks. In C, C++ the brackets also provide some "pseudo-whitespace" as there is only a single opening/closing brace on some lines, so this also serves to break up the code density.
Your code is fine, just do what you (and others you might work with) are comfortable with.
The only thing I see wrong with some (inexperienced) programmers about whitespace is that they can be afraid to use it, which is not true in this case.
I did however notice that you did not use more than one consecutive blank line in your sample code, which, in certain cases, you should use.
Here is how I would refactor that method. Things can surely still be improved and I did not yet refactor the PiggyBack class (I just moved it to an upper level).
By using the Composed Method pattern, the code becomes easier to read when it's divided into methods that each do one thing and work on a single level of abstraction. Also less comments are needed. Comments that answer to the question "what" are code smells (i.e. the code should be refactored to be more readable). Useful comments answer to the question "why", and even then it would be better to improve the code so that the reason will be obvious (sometimes that can be done by having a test that will fail without the inobvious code).
public CommandThread[] buildCommandsForExecution() {
CommandLine cLine = buildCommandLine();
CommandThread command = buildCommandThread(cLine);
initPiggyBack(command);
return new CommandThread[]{command};
}
private CommandLine buildCommandLine() {
CommandLine cLine = new CommandLine(getValue(OptionConstants.EXECUTABLE));
// "--test" must be first, and bucket and file location must be last,
// because [TODO: enter the reason]
cLine.addOption(getOption(OptionConstants.TEST));
for (Option regularOption : getRegularOptions()) {
cLine.addOption(regularOption);
}
cLine.addOption(getOption(OptionConstants.BUCKET));
cLine.addOption(getOption(OptionConstants.FILE_LOCATION));
return cLine;
}
private List<Option> getRegularOptions() {
List<Option> options = getAllOptions();
options.removeAll(getNonRegularOptions());
return options;
}
private List<Option> getAllOptions() {
List<Option> options = new ArrayList<Option>();
for (OptionBox optionBox : optionBoxes.values()) {
options.add(optionBox.getOption());
}
return options;
}
private List<Option> getNonRegularOptions() {
OptionConstants[] nonRegular = {
OptionConstants.BUCKET,
OptionConstants.FILE_LOCATION,
OptionConstants.TEST,
OptionConstants.EXECUTABLE,
OptionConstants.MOUNT_LOCATION
};
List<Option> options = new ArrayList<Option>();
for (OptionConstants c : nonRegular) {
options.add(getOption(c));
}
return options;
}
private CommandThread buildCommandThread(CommandLine cLine) {
GUIInteractiveCommand command = new GUIInteractiveCommand(cLine, console);
command.addComponentsToEnable(enableOnConnect);
command.addComponentsToDisable(disableOnConnect);
if (isMountLocationSet()) {
command.addComponentToEnable(mountButton);
}
return command;
}
private boolean isMountLocationSet() {
String mountLocation = getValue(OptionConstants.MOUNT_LOCATION);
return !mountLocation.equals("");
}
private void initPiggyBack(CommandThread command) {
PiggyBack piggyBack = new PiggyBack();
piggyBack.setConsole(console);
command.setNextLink(piggyBack);
}
For C#, I say "if" is just a word, while "if(" is code - a space after "if", "for", "try" etc. doesn't help readability at all, so I think it's better without the space.
Also: Visual Studio> Tools> Options> Text Editor> All Languages> Tabs> KEEP TABS!
If you're a software developer who insists upon using spaces where tabs belong, I'll insist that you're a slob - but whatever - in the end, it's all compiled. On the other hand, if you're a web developer with a bunch of consecutive spaces and other excess whitespace all over your HTML/CSS/JavaScript, then you're either clueless about client-side code, or you just don't give a crap. Client-side code is not compiled (and not compressed with IIS default settings) - pointless whitespace in client-side script is like adding pointless Thread.Sleep() calls in server-side code.
I like to maximize the amount of code that can be seen in a window, so I only use a single blank line between functions, and rarely within. Hopefully your functions are not too long. Looking at your example, I don't like a blank line for an open brace, but I'll have one for a close. Indentation and colorization should suffice to show the structure.