Refactor: use git log -S ... -p ... and strip diffs

[Kraymer]

ublame is pretty close of what git log -S ... -p ... do : its diff is more concise and readable but it is way slower.

This refactoring consists in capturing git log -S ... -p ... output and stripping it to achieve current ublame output :

Algo would be :

• extract diff by regex capturing text between @ and @ / commit hexa lines
• if diff contain token keep it, otherwise discard it

❯ git log -G "ublame_cli" -p ublame/__init__.py
commit 90e286119ac29090f54115bc5a908f1488d0d98b
Author: Fabrice Laporte <fabrice@yescapa.com>
Date:   Sun Nov 15 10:25:49 2020 +0100

    feat: accept multiple patterns as input

───────────────────────────────────────────────────────────────────────────────
modified: ublame/__init__.py
───────────────────────────────────────────────────────────────────────────────
@ ublame/__init__.py:41 @ def repo_path_for(filename):
            return filename


def trim_diff(diff, token, context=3):
def trim_diff(diff, patterns, context=3):
    """Keep only context surrounding searched token."""
    if token in diff:
[...]
    return any(diffs) or found
 

@click.argument("patterns", nargs=-1, required=True)
def ublame_cli(filename, patterns):
    filename = os.path.abspath(filename)
    repo_path = repo_path_for(filename)
[...]

───────────────────────────────────────────────────────────────────────────────
added: ublame/__init__.py
───────────────────────────────────────────────────────────────────────────────
@ ublame/__init__.py:4 @
import blessed
import os
import click
from pydriller import RepositoryMining, GitRepository
 
...