git-bisect, but for n repos

This shows that you can do without a run script if you write the test on a single line.,Locate a good region of the object graph in a damaged repository, Automatically bisect a broken test case: $ git bisect start HEAD HEAD~10 -- # culprit is among the last 10 $ git bisect run sh -c "make || exit 125; ~/check_test_case.sh" $ git bisect reset # quit the bisect session This shows that you can do without a run script if you write the test on a single line. ,Once you have specified at least one bad and one good commit, git bisect selects a commit in the middle of that range of history, checks it out, and outputs something similar to the following:

git bisect <subcommand>
   <options>

git bisect start [--term-{new,bad}=<term> --term-{old,good}=<term>]
	  [--no-checkout] [--first-parent] [<bad> [<good>...]] [--] [<paths>...]
git bisect (bad|new|<term-new>) [<rev>]
git bisect (good|old|<term-old>) [<rev>...]
git bisect terms [--term-good | --term-bad]
git bisect skip [(<rev>|<range>)...]
git bisect reset [<commit>]
git bisect (visualize|view)
git bisect replay <logfile>
git bisect log
git bisect run <cmd>...
git bisect help

$ git bisect start
$ git bisect bad # Current version is bad
$ git bisect good v2 .6 .13 - rc2 # v2 .6 .13 - rc2 is known to be good

Bisecting: 675 revisions left to test after this(roughly 10 steps)

$ git bisect good

$ git bisect bad

Suggestion : 2

First, we need to initialize a repository to track our work.

mkdir test_git_bisect && cd test_git_bisect && git init

Let's say we are going to make a script that gets an epoch and converts it to

datetime

The python script parse_epochs.py we will use here is nothing special.

from time
import localtime, strftime

with open('epochs.txt', 'r') as handler:
   epochs = handler.readlines()
for epoch in epochs:
   current_datetime = strftime('%Y-%m-%d %H:%M:%S', localtime(int(epoch)))
print(current_datetime)

Let's amend the input now to make it faulty:

echo "random string" >> epochs.txt

and commit again:

git add. && git commit - m "Added faulty input"

Suggestion : 3

If you are inside an existing Git repository, step out of it. You need to find a different location since we will clone a new repository.,If you annotate in a terminal and the file is longer than the screen, Git by default uses the program less to scroll the output. Use /sometext <ENTER> to find “sometext” and you can cycle through the results with n (next) and N (last). You can also use page up/down to scroll. You can quit with q.,While git grep searches the current state of the repository, it is also possible to search through all changes for “sometext”:,With git grep you can find all lines in a repository which contain some string or regular expression. This is useful to find out where in the code some variable is used or some error message printed:

$ git status

fatal: not a git repository(or any of the parent directories): .git

$ git grep sometext
$ git grep "some text with spaces"

$ git clone https: //github.com/networkx/networkx
   $ cd networkx
$ git grep - i fixme

$ git log - S sometext

$ git log - S test_weakly_connected_component

Suggestion : 4

Think of a binary search but for debugging. You can bisect commits to find a bug by finding a commit where it doesn't repro. Check the commit halfway between master and that one. Depending on whether or not it repros, check the halfway point between those commits, etc.,After a good and bad commit have been declared, git will checkout the commit halfway between the two. You’ll see some output like this:,Git will automatically check out the next commit between the commit we just labeled as good, and our starting point bad commit:,I left that extra little message in the commit so we could be sure that the bisect was correct in finding the origin of the bug. Pretty amazing, huh? Now if only we had a test in place to speed up this process and make it a little less error prone.

refactor: Extract Function - > amountFor

refactor: prev - > renaming variables

commit c12489cca6cffbee4998bd3c45bfb36a387fb128
Author: Jimmy DC <jimmydalecleveland@gmail.com>
   Date: Wed Apr 8 08:48:23 2020 -0600

   refactor: Extract Function -> volumeCreditsFor()

   !! I introduced a bug here !!

# Here 's the original correct output: >
   $ node index.js 'Statement for BigCo\n' +
   '  Hamlet: $650.00 (55 seats)\n' +
   '  As You Like It: $580.00 (35 seats)\n' +
   '  Othello: $500.00 (40 seats)\n' +
   'Amount owed is $1,730.00\n' +
   'You earned 47 credits\n'

# Here is the output with the bug:
   >
   $ node index.js 'Statement for BigCo\n' +
   '  Hamlet: $650.00 (55 seats)\n' +
   '  As You Like It: $580.00 (35 seats)\n' +
   '  Othello: $500.00 (40 seats)\n' +
   'Amount owed is $1,730.00\n' +
   'You earned 137 credits\n'

git bisect start