Dmitrii,

I use a different approach, where I tangle the source into files in modules
and then I import those modules from other blocks.
This allows me to organize my document with different sections for the code
and its tests, which then get exported into their corresponding files.


* Square Function

This function receives a number and returns its square

#+BEGIN_SRC python :tangle ./utils/math.py :mkdirp yes
def square(x):
    return x * x
#+END_SRC

** __init__.py (module setup)

#+begin_src python :tangle ./utils/__init__.py :mkdirp yes
from utils.math import square

#+end_src

** Test cases

1. The square of five should be 25
2. The square of zero should be 0
3. The square of a negative number should be positive

#+BEGIN_SRC python :tangle ./utils/test_square.py :mkdirp yes
from utils.math import square

def test_square_of_five():
    assert square(5) == 25

def test_square_of_zero():
    assert square(0) == 0

def test_square_of_negative():
    assert square(-5) > 0
#+END_SRC

*** Run tests

#+begin_src sh :results output raw
pytest ./utils
#+end_src

#+RESULTS:
============================= test session starts
==============================
platform linux -- Python 3.7.3, pytest-4.6.3, py-1.8.0, pluggy-0.12.0
rootdir: /app
collected 3 items

utils/test_square.py ...
[100%]

=========================== 3 passed in 0.08 seconds
===========================






On Wed, Apr 24, 2019 at 2:19 PM Dmitrii Korobeinikov <dim1212k@gmail.com>
wrote:

> Sorry for not answering these two days.
>
> You are right, that's an option.
> But I just don't think that's the best possible one - for usability.
>
> Introducing this would imply architectural decisions, so it might not be
> immediately clear if it's right or not.
> Especially that the improvement might not seem that big.
> So, I understand that.
>
> I have proposed buffer lenses today and they seem like something that can
> solve the issue from the user side. Hopefully they will get some traction.
>
> пн, 22 апр. 2019 г. в 23:31, Berry, Charles <ccberry@ucsd.edu>:
>
>>
>>
>> > On Apr 22, 2019, at 10:15 AM, Dmitrii Korobeinikov <dim1212k@gmail.com>
>> wrote:
>> >
>> > Thank you!
>> > That's a handy technique and it does help.
>> > As I understand, there's no way to extend that to multiple lines?
>>
>> AFAICS, no there is no way to split the :epilogue arg to multiple lines.
>>
>> Of course, you can always follow a src block that provides a function
>> with another src block that imports the code via noweb and then tests the
>> function with as many lines of code as you need.
>>
>> Chuck
>>
>>
>>
>>