Re: Is it possible to test local funtion with lunit?

[Dirk Laurie <dirk.laurie@...>]

2014-07-31 6:37 GMT+02:00 Coda Highland <chighland@gmail.com>:
> On Wed, Jul 30, 2014 at 7:03 PM, albert_200200 <albert_200200@126.com> wrote:
>> Really thanks for your quick reply. Your following meaning I didn't
>> understand well. Do you mean every method I want to make sure it's correct
>> and to test,  I should make this method public, Is that your meaning?
>
> No, that's the opposite of what I was trying to say. I'm trying to say
> that tests shouldn't be poking at the internals. Tests should be just
> like user code -- they should test the functions that the user can
> call, and the private functions should be implementation details that
> the tests shouldn't have to know about.
>
> The other part I was saying is that there are ways to work around it
> if, in the end, you decide that you have some internal function that
> REALLY, REALLY needs tested on its own but shouldn't be exposed to the

One of my first lessons as a young programmer was taught to
me by my boss, who himself was a mathematician who did
not write programs. It was:

   A program without documentation is totally useless;
   documentation without a program is very useful.

I dismissed it as typical of the person who was saying it, and
told him so (it was that kind of organization). He "explained"
by handing me the specifications of a program, part of
a closed-source package, that could evaluate an integral
numerically to high precision. Then he told me to go and write
a program that could do what was described, with exactly the
same Fortran interface.

Any software you make public should have documentation
as accurate as the Lua manual, and your testing should be
designed to check that it does what your manual says.

What I have done in some of my modules is to make them
return two values. Then `require "mymod"` only accesses the
public part, but `mymod, private = dofile"mymod.lua"` also
returns a table containing some local functions, cached
while they were visible. Then `lunit` or a similar tool can test
`mymod`, and some special-purpose tool that I have control
over can test `private`.