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digitalmars.D.learn - unittest questions

reply Johannes Pfau <spam example.com> writes:
Hi, I wrote some unittests using the built-in d unittest and a came
across 2 problems:

1) I have some code that accepts both delegates and functions. How can a
unittest explicitly check the function part? Whenever I add a function
in an unittest block it becomes a delegate.
---------------------------------------------------
void add(T)(T handler) if (is(T == void function())){}
void add(T)(T handler) if (is(T == void delegate())){}

unittest
{
    //always a delegate
    void handler() {};
    add(&handler);
}
----------------------------------------------------

2) I know Errors should not be caught. But when I expect a function to
throw in debug mode, but not necessarily in release mode (assert), I
have to check for both Errors and Exceptions --> Throwable. Is it OK to
catch Throwables in this case?
----------------------------------------------------
unittest
{
    void handler() {};
    bool thrown = false;
    try
        add(&handler);
    catch(Throwable)
        thrown = true;

    assert(thrown);
}
----------------------------------------------------

-- 
Johannes Pfau
Aug 19 2010
next sibling parent bearophile <bearophileHUGS lycos.com> writes:
Johannes Pfau:

 1) I have some code that accepts both delegates and functions. How can a
 unittest explicitly check the function part? Whenever I add a function
 in an unittest block it becomes a delegate.

You may define it outside the unittest{} block (that is a function) and wrap everything inside a version(unittest){} block. Bye, bearophile
Aug 19 2010
prev sibling next sibling parent "Simen kjaeraas" <simen.kjaras gmail.com> writes:
Johannes Pfau <spam example.com> wrote:

 Hi, I wrote some unittests using the built-in d unittest and a came
 across 2 problems:

 1) I have some code that accepts both delegates and functions. How can a
 unittest explicitly check the function part? Whenever I add a function
 in an unittest block it becomes a delegate.
 ---------------------------------------------------
 void add(T)(T handler) if (is(T == void function())){}
 void add(T)(T handler) if (is(T == void delegate())){}

 unittest
 {
     //always a delegate
     void handler() {};
     add(&handler);
 }
 ----------------------------------------------------

You can use version statements[1] to place the function outside the unittest scope: version( unittest ) { void handler() {} } unittest { add( &handler ); } You could also use function literals[2]: unittest { add( function void() {} ); }
 2) I know Errors should not be caught. But when I expect a function to
 throw in debug mode, but not necessarily in release mode (assert), I
 have to check for both Errors and Exceptions --> Throwable. Is it OK to
 catch Throwables in this case?
 ----------------------------------------------------
 unittest
 {
     void handler() {};
     bool thrown = false;
     try
         add(&handler);
     catch(Throwable)
         thrown = true;

     assert(thrown);
 }
 ----------------------------------------------------

Yes. [1]: http://www.digitalmars.com/d/2.0/version.html#version http://www.digitalmars.com/d/2.0/version.html#PredefinedVersions [2]: http://www.digitalmars.com/d/2.0/expression.html#FunctionLiteral -- Simen
Aug 19 2010
prev sibling next sibling parent reply Jonathan M Davis <jmdavisprog gmail.com> writes:
On Thursday, August 19, 2010 11:08:33 Johannes Pfau wrote:
 Hi, I wrote some unittests using the built-in d unittest and a came
 across 2 problems:
 
 1) I have some code that accepts both delegates and functions. How can a
 unittest explicitly check the function part? Whenever I add a function
 in an unittest block it becomes a delegate.
 ---------------------------------------------------
 void add(T)(T handler) if (is(T == void function())){}
 void add(T)(T handler) if (is(T == void delegate())){}
 
 unittest
 {
     //always a delegate
     void handler() {};
     add(&handler);
 }
 ----------------------------------------------------
 
 2) I know Errors should not be caught. But when I expect a function to
 throw in debug mode, but not necessarily in release mode (assert), I
 have to check for both Errors and Exceptions --> Throwable. Is it OK to
 catch Throwables in this case?
 ----------------------------------------------------
 unittest
 {
     void handler() {};
     bool thrown = false;
     try
         add(&handler);
     catch(Throwable)
         thrown = true;
 
     assert(thrown);
 }
 ----------------------------------------------------

If you declare a nested function as static, it shouldn't be a delegate. Also, I don't believe that you need the semicolon after the function declaration. - Jonathan m Davis
Aug 19 2010
parent Johannes Pfau <spam example.com> writes:
On 20.08.2010 01:17, Jonathan M Davis wrote:
 If you declare a nested function as static, it shouldn't be a delegate. Also,
I 
 don't believe that you need the semicolon after the function declaration.
 
 - Jonathan m Davis

Thanks for all the answers. I guess I'll just declare the functions as static, that seems to be the best solution. -- Johannes Pfau
Aug 20 2010
prev sibling parent "Steven Schveighoffer" <schveiguy yahoo.com> writes:
On Thu, 19 Aug 2010 14:08:33 -0400, Johannes Pfau <spam example.com> wrote:

 Hi, I wrote some unittests using the built-in d unittest and a came
 across 2 problems:

 1) I have some code that accepts both delegates and functions. How can a
 unittest explicitly check the function part? Whenever I add a function
 in an unittest block it becomes a delegate.
 ---------------------------------------------------
 void add(T)(T handler) if (is(T == void function())){}
 void add(T)(T handler) if (is(T == void delegate())){}

 unittest
 {
     //always a delegate
     void handler() {};
     add(&handler);
 }
 ----------------------------------------------------

I know others have answered this, but to aid in your understanding of *why* it works this way, a unittest block is actually a function itself. So declaring a function inside it is like declaring a nested function. In essence, the compiler lumps together all of your unit test blocks into one function per module, and stores a pointer to that function in a ModuleInfo object. Then the runtime calls all of these functions on startup.
 2) I know Errors should not be caught. But when I expect a function to
 throw in debug mode, but not necessarily in release mode (assert), I
 have to check for both Errors and Exceptions --> Throwable. Is it OK to
 catch Throwables in this case?
 ----------------------------------------------------
 unittest
 {
     void handler() {};
     bool thrown = false;
     try
         add(&handler);
     catch(Throwable)
         thrown = true;

     assert(thrown);
 }
 ----------------------------------------------------

I'd say that the appropriate thing to do here is to catch the exceptions you would expect to be thrown i.e.: unittest { void handler() {}; bool thrown = false; try add(&handler); catch(DerivedFromException) thrown = true; catch(DerivedFromError) thrown = true; assert(thrown); } ideally, you should be able to predict which exception gets thrown so you only have one catch statement. The point of unit tests are to ensure behavior is within specifications. If your specification is that a function can throw anything, then I think the specification needs work. -Steve
Aug 23 2010