[GSOC][RFC] microproject: use test_path_is_* functions in test scripts

[Vincenzo MEZZELA <vincenzo.mezzela@gmail.com>]

Hello everyone,

I'm Vincenzo, a Master's degree student in Computer Engineering and 
Cybersecurity.

As I'm approaching the end of my academic journey, I'm eager to 
contribute to the Git project
and the GSoC represents a good opportunity to do so. Upon exploring the 
online documentation
of git for the application to the GSoC I'm keen to begin the required 
microproject.

Among the microproject proposed here 
https://git.github.io/SoC-2024-Microprojects/ , I would like to
work on replacing 'test -(e|f|g|...)' with test_path_is* .

Can you confirm if this task has already been taken by someone else?


Approach:

As far as I understood, The work consists in replacing the shell 'test' 
command in the test
script under 't/' directory with the ones present in the 
t/test_lib_functions.sh as follows:

- test -f --> test_path_is_file

- test -d --> test_path_is_dir

- test -e --> test_path_exists


To approximately measure the number of required replacement, I run the 
following commands from the
't/' directory (branch master):

> # Files  that requires a replacement
 > git grep -r 'test -[efdx]' 2>/dev/null| awk '{print $1}' | uniq -c | 
sort -n -r
>>    190 t7301-clean-interactive.sh:
>>     147 t7300-clean.sh:
>>      21 t2004-checkout-cache-temp.sh:
>>      17 t2401-worktree-prune.sh:
>>      16 t2003-checkout-cache-mkdir.sh:
>>      14 t0601-reffiles-pack-refs.sh:
>>      13 t4200-rerere.sh:
>>      12 t9146-git-svn-empty-dirs.sh:
>>      12 t7603-merge-reduce-heads.sh:
>>      12 lib-submodule-update.sh:
>>    ...
 >>
 > # Number of replacements
 > git grep -r 'test -[efdx]' 2>/dev/null| awk '{print $1}' | uniq -c | 
sort -n -r | awk '{sum += $1} END {print sum}'
 >> 853
 > # Number of files that requires a patch
 > git grep -r 'test -[efdx]' 2>/dev/null| awk '{print $1}' | uniq -c | 
wc -l
 >> 169

Although the replacement work might not be difficult, it spans over many 
different test files.
Do you want me to submit a patch for each of them as part of the 
microproject?
If not, How many patches do you expect me to submit?

Thanks,
Vincenzo