Philip A Senger psenger

Localstack Cheat Sheet

Environment

I put everything in us-east-1 so this might not be for you.

export AWS_ACCESS_KEY_ID="test"
export AWS_SECRET_ACCESS_KEY="test"
export AWS_DEFAULT_REGION="us-east-1"

The Nullish Coalescing Operator `??`and Logical OR Operator `||`

value	const assign = value ?? 'right'	const assign = value \|\| 'right'
null	right	right
undefined	right	right
'""'	left	right
0	left	right
[]	left	left
NaN	right	right

Backup and Recovery of Postgres

Backup

pg_dump --dbname=<database_name> \
--inserts \
--format=d \
--create \
--file= \

Git Cleanup

Cleanup unnecessary files and optimize the local repository

Runs a number of housekeeping tasks within the current repository, such as compressing file revisions (to reduce disk space and increase performance), removing unreachable objects which may have been created from prior invocations of git add, packing refs, pruning reflog, rerere metadata or stale working trees. May also update ancillary indexes such as the commit-graph.

When common porcelain operations that create objects are run, they will check whether the repository has grown substantially since the last maintenance, and if so run git gc automatically. See gc.auto below for how to disable this behavior.

Running git gc manually should only be needed when adding objects to a repository without regularly running such porcelain commands, to do a one-off repository optimization, or e.g. to clean up a suboptimal mass-import. See the "PACKFILE OPTIMIZATION" section in git-fast-import(1) for more details on the import case.

Compare two branches to find commits in one but not the other

git-cherry - Find commits yet to be applied to upstream. Essential for rebase and merging.

Patch workflows

git-cherry is frequently used in patch-based workflows (see gitworkflows(7)) to determine if a series of patches has been applied by the upstream maintainer. In such a workflow you might create and send

a topic branch like this:

Finding a committed bug with Git CLI

git-bisect - Use binary search to find the commit that introduced a bug

Basic bisect commands: start, bad, good

As an example, suppose you are trying to find the commit that broke a feature that was known to work in version v2.6.13-rc2 of your project. You start a bisect session as follows:

	/**
	* Function: moveZeros
	* Description: This function moves all zeros in an array to the end of the array, while
	* preserving the order of the other elements. Without creating a new Array.
	* Note: this uses a common two-pointer method, is O(n) and does not create a new array
	* @param {Array} nums - The input array.
	* @return {Array} The modified input array.
	*/
	const moveZeros = (nums) => {
	let left = 0

	def auto_str(cls):
	def __str__(self):
	return '%s(%s)' % (
	type(self).__name__,
	', '.join('%s=%s' % item for item in vars(self).items())
	)

	cls.__str__ = __str__
	return cls

	# install_certifi.py
	#
	# sample script to install or update a set of default Root Certificates
	# for the ssl module. Uses the certificates provided by the certifi package:
	# https://pypi.python.org/pypi/certifi

	import os
	import os.path
	import ssl
	import stat

	## One liner to remove Duplicates from an array and keep order.

	old = ['a', 'b', 'a', 'c', 'b', 'a']
	new = list(dict.fromkeys(old).keys())