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digitalmars.D.learn - Dlang tour - Unittesting example

reply Joe <jma freedomcircle.com> writes:
There appears to be a problem with the example at

https://tour.dlang.org/tour/en/gems/unittesting

If compiled with -unittest, the resulting program crashes. It 
happens with ldc2 on Linux but it can also be seen if you click 
on "Export" and run it with dmd -unittest.
Oct 01 2018
parent reply bauss <jj_1337 live.dk> writes:
On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. It 
 happens with ldc2 on Linux but it can also be seen if you click 
 on "Export" and run it with dmd -unittest.


I think it's more likely a problem with your OS.

I am unable to reproduce that with either of dmd or ldc.
Oct 02 2018
next sibling parent reply Joe <jma freedomcircle.com> writes:
On Tuesday, 2 October 2018 at 09:59:28 UTC, bauss wrote:

 On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. It 
 happens with ldc2 on Linux but it can also be seen if you 
 click on "Export" and run it with dmd -unittest.


 I think it's more likely a problem with your OS.

 I am unable to reproduce that with either of dmd or ldc.


Well then it's also a problem with run.dlang.io, since as I said 
it also happens when you run it there.
Oct 02 2018
parent reply Joe <jma freedomcircle.com> writes:
On Tuesday, 2 October 2018 at 12:25:19 UTC, Joe wrote:

 On Tuesday, 2 October 2018 at 09:59:28 UTC, bauss wrote:

 On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. It 
 happens with ldc2 on Linux but it can also be seen if you 
 click on "Export" and run it with dmd -unittest.


 I think it's more likely a problem with your OS.

 I am unable to reproduce that with either of dmd or ldc.


 Well then it's also a problem with run.dlang.io, since as I 
 said it also happens when you run it there.


I forgot to mention: at the end, it reports "1/1 unittests 
FAILED". I see three tests--two in the struct and the separate 
one--but the assertion failure is in line 49 (the standalone) so 
apparently the other two are not being run (or reported).
Oct 02 2018
next sibling parent reply Basile B. <b2.temp gmx.com> writes:
On Tuesday, 2 October 2018 at 12:30:36 UTC, Joe wrote:

 On Tuesday, 2 October 2018 at 12:25:19 UTC, Joe wrote:

 On Tuesday, 2 October 2018 at 09:59:28 UTC, bauss wrote:

 On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. 
 It happens with ldc2 on Linux but it can also be seen if you 
 click on "Export" and run it with dmd -unittest.


 I think it's more likely a problem with your OS.

 I am unable to reproduce that with either of dmd or ldc.


 Well then it's also a problem with run.dlang.io, since as I 
 said it also happens when you run it there.


 I forgot to mention: at the end, it reports "1/1 unittests 
 FAILED". I see three tests--two in the struct and the separate 
 one--but the assertion failure is in line 49 (the standalone) 
 so apparently the other two are not being run (or reported).


The problem is the NaN madness.
Since several values are NaN there's this strange stuff:

void main()
{
     import std.stdio;
     import std.math : isNaN;
     double d;

     writeln(d.init);    // nan
     writeln(d);         // nan
     writeln(d.nan);     // nan

     assert(d.isNaN);
     assert(d == d.nan);  // fails
     assert(d == d.init); // fails
}

the last assert is just crazy.
Oct 02 2018
next sibling parent ag0aep6g <anonymous example.com> writes:
On 10/02/2018 03:24 PM, Basile B. wrote:

 The problem is the NaN madness.
 Since several values are NaN there's this strange stuff:
 
 void main()
 {
      import std.stdio;
      import std.math : isNaN;
      double d;
 
      writeln(d.init);    // nan
      writeln(d);         // nan
      writeln(d.nan);     // nan
 
      assert(d.isNaN);
      assert(d == d.nan);  // fails
      assert(d == d.init); // fails
 }
 
 the last assert is just crazy.


NaN simply isn't equal to itself. Has nothing to do with there being 
multiple NaNs. `d == d`, `double.nan == double.nan`, `double.init == 
double.init` are all false, too.
Oct 02 2018
prev sibling parent Joe <jma freedomcircle.com> writes:
On Tuesday, 2 October 2018 at 13:24:09 UTC, Basile B. wrote:

 The problem is the NaN madness.
 Since several values are NaN there's this strange stuff:

 void main()
 {
     import std.stdio;
     import std.math : isNaN;
     double d;

     writeln(d.init);    // nan
     writeln(d);         // nan
     writeln(d.nan);     // nan

     assert(d.isNaN);
     assert(d == d.nan);  // fails
     assert(d == d.init); // fails
 }

 the last assert is just crazy.


OK, so changing the example from

     // .init a special built-in property that
     // returns the initial value of type.
     assert(vec.x == double.init);

to

     import std.math : isNaN;
     assert(vec.x.isNaN);

doesn't cause the crash. Although I'm a bit puzzled still, I 
thought (coming from Python) that when you ran the unittest 
version it would report which tests passed and which failed, not 
run through main().
Oct 02 2018
prev sibling parent Steven Schveighoffer <schveiguy gmail.com> writes:
On 10/2/18 8:30 AM, Joe wrote:

 On Tuesday, 2 October 2018 at 12:25:19 UTC, Joe wrote:

 On Tuesday, 2 October 2018 at 09:59:28 UTC, bauss wrote:

 On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. It 
 happens with ldc2 on Linux but it can also be seen if you click on 
 "Export" and run it with dmd -unittest.


 I think it's more likely a problem with your OS.

 I am unable to reproduce that with either of dmd or ldc.


 Well then it's also a problem with run.dlang.io, since as I said it 
 also happens when you run it there.


 
 I forgot to mention: at the end, it reports "1/1 unittests FAILED". I 
 see three tests--two in the struct and the separate one--but the 
 assertion failure is in line 49 (the standalone) so apparently the other 
 two are not being run (or reported).


I will note that the granularity of the unittests is based on how many 
*modules* were tested. There is only one unittest function in each 
ModuleInfo (as provided by the compiler to the runtime), so that's the 
number that's being reported. So in this case, it's not missing 
unittests, it's running all given unit tests.

-Steve
Oct 02 2018
prev sibling parent Jonathan M Davis <newsgroup.d jmdavisprog.com> writes:
On Tuesday, October 2, 2018 3:59:28 AM MDT bauss via Digitalmars-d-learn 
wrote:

 On Tuesday, 2 October 2018 at 04:13:01 UTC, Joe wrote:

 There appears to be a problem with the example at

 https://tour.dlang.org/tour/en/gems/unittesting

 If compiled with -unittest, the resulting program crashes. It
 happens with ldc2 on Linux but it can also be seen if you click
 on "Export" and run it with dmd -unittest.


 I think it's more likely a problem with your OS.

 I am unable to reproduce that with either of dmd or ldc.


IIRC, we use stdc for formatting floating values and not pure D code
(because correctly converting floating point values to strings is really,
really complicated to implement). So, the result is going to depend on the
system that it's run on. It fails on my system (64-bit FreeBSD). Honestly,
this is basically the same thing as comparing floating point values with ==.
You shouldn't do it. So, I'd argue that it's just plain a bad example.

- Jonathan M Davis
Oct 02 2018