`repypp.py` should have unit tests

[aaaaalbert]

repypp.py, the Repy preprocessor, does not have unit tests. This makes testing parts of the build scripts in SeattleTestbed/common difficult.

Things we should probably test:

• Correct #include statements
• Erroneous #include statements:
  • include non-existing files,
  • have multiple arguments,
  • have no arguments at all.

(We will want to have realistic-looking Repy programs and realistic-looking libraries to #include for these purposes).

[aaaaalbert]

@XuefengHuang suggested we also test calling repypp.py with too few / many arguments. Good point!

I'll also add that we should test lines like
include some_lib.repy # Ensure that comments are ignored, even if preceded by whitespace

[XuefengHuang]

I have added some unit tests to check different situations as the issue describes. This is my PR(#163).

[asm582]

I have tested this on linux - ubuntu and below are the test cases that pass:

-rw-rw-r-- 1 cib cib 878 May 15 22:07 ut_seattlelibv2_repypp_samearguments.py
-rw-rw-r-- 1 cib cib 777 May 15 22:07 ut_seattlelibv2_repypp_noargument.py
-rw-rw-r-- 1 cib cib 1648 May 15 22:07 ut_seattlelibv2_repypp_multiplearguments.py
-rw-rw-r-- 1 cib cib 1133 May 15 22:07 ut_seattlelibv2_repypp_include_specifiedfile.py
-rw-rw-r-- 1 cib cib 1113 May 15 22:07 ut_seattlelibv2_repypp_include_non-existingfiles.py
-rw-rw-r-- 1 cib cib 1037 May 15 22:07 ut_seattlelibv2_repypp_include_noargument.py
-rw-rw-r-- 1 cib cib 1560 May 15 22:07 ut_seattlelibv2_repypp_include_multiplearguments.py
-rw-rw-r-- 1 cib cib 1274 May 15 22:07 ut_seattlelibv2_repypp_include_filecontent.py
-rw-rw-r-- 1 cib cib 1549 May 15 22:07 test_repypp_library.pyc

Below is the test case that fail:-

cib@cib-VirtualBox:~/xeufeng/seattlelib_v2/RUNNABLE$ python utf.py -f ut_seattlelibv2_repypp_specialcomments.py
Testing module: seattlelibv2

Running: ut_seattlelibv2_repypp_specialcomments.py [ FAIL ]

Standard out :
..............................Produced..............................
Error opening source file 'testfile_repypp_example1.repy # Ensure that comments are ignored, even if preceded by whitespace'
the result of repypp.py produces is not correct!

..............................Expected..............................

None

and test case leaves and trace of file that i think can be removed by os.remove, below is the file:

-rw-rw-r-- 1 cib cib 86 May 15 22:11 testfile_repypp_example3.repy