gaganawhad/activerecord-cheatsheet.md

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This cheatsheet has been moved to Obisidian for now. Don't make edits here!!!!! Cheatsheet for git, rails, unix etc.

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activerecord-cheatsheet.md

Jsonb AR querying:

All records where a particular key is present:

Groupings::Collection.where("document ? 'name'")

OR

Groupings::Collection.where("document ? :key", {key: 'name'}).
Search for records where document attribute is not null:

Contents::Audio.s3.where("document->>'s3_file_path' IS NOT NULL")
Article on jsonb querying: https://nandovieira.com/using-postgresql-and-jsonb-with-ruby-on-rails
Query all records for a specific value stored in the jsonb column.

Contents::Document.where("document ->> 'file_content_type' = ?", 'application/octet-stream')

Helpful resource https://makandracards.com/makandra/37851-how-to-query-postgresql-s-json-fields-from-rails

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browser-console.md

    Open load all github files that are not loaded.

document.querySelectorAll('.load-diff-button').forEach(node => node.click())

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git-cheatsheet.md

Git

Version of git

git --version
View user name and email for current user:

git config user.name

git config user.email
Change user name and email for current repository:

git config user.name "Gagan"

git config user.email "blah@blah.com"
Change user name and email for all repositories:

git config --global user.name "Gagan"

git config --global user.email "blah@blah.com"
Set the colors for git:

git config --global color.ui true

Set default pager for git

#Default is less. Setting to '' will stop the use of pager
git config --global core.pager ''

Remote

Add a git remote:

git remote add <remote-name> gt@giturl.git
Remove a git remote:

git remote rm <remote-name>
View git remotes: git remote -v

Pulling, adding, committing and related commands

To add the same file in patches, so that they can be committed under different commits:

git add filename -p
To stage all the files that are delete locally:

git rm $(git ls-files --deleted)
To see the difference of files that are staged

git diff --cached or git diff --staged
To see more context than just 3 lines in a git diff

git diff -U7
To change your last commit message do

git commit --amend
To push from a branch to github do

git push origin <local-branchname>(:<remote-branchname>)
Dry run your push

git push --dry-run origin <local-branchname>(:<remote-branchname>)

It is often better to test out what changes will happen with you push. The options to use to do that is --dry-run

Listing files

deleted files:

git ls-files --deleted
all untracked files:

git ls-files -o
all files that git has ignored:

git ls-files --exclude-standard
untracked files that git doesn't ignore (i.e. all new files):

git ls-files --other --exclude-standard
Files that match a pattern:

git ls-files vendor*
Removing ignored file from the repository:

To delete a file from the repository but keep it in your working directory (this might come in handy when the file has been ignored)

git rm --cached <file>

Clean

Remove untracked files dry run: git clean -n

clean untacked files

git clean -f

OR rm -r $(git ls-files --other --exclude-standard)

clean untracked files and directories

git clean -f -d

git clean untraced files including ignored files

git clean -f -x

options -d removes directory -n dry-run, -f force, -x remove files ignored by .gitignore

Reverting

To revert changes done to a particular file in a particular commit you can use the command.

git checkout <sha-of-commit> <path-to-file>

Checkout

When in the middle of conflict while merging branches

And you want to keep the changes in a file as the were in the trunk:

git checkout --ours index.html

or you want to keep changes in a file as they were in the branch:

git checkout --theirs layouts/default.html

tagging

Adding a tag git tag -a '<tag-number>' -m 'tag-message'
push all tags git push --tags
delete tag locally git tag -d <tag-number>
delete a tag in the repository that has been remove locally git push origin :refs/tags/<tag-number>
add a tag to the sha git tag <tag-number> <sha-of-commit> -m "message of tag"

branching & merging

To see all branches including all branches (ie local and remote):

git branch -a
To create a new branch from a particular commit that exists in the log of current branch

git branch branchname sha-of-commit
Delete a branch in repository that is deleted locally

git push origin :feature/sass i.e. add colon before the branch name
Create a branch from a previous commit: git branch branchname <sha1-of-commit>
List existing remote branches: git ls-remote --heads
Use a mergetool to help resolve conflicts git mergetool

gui

Git's Graphical user interface git gui

bisect

Find the commit that introduces a bug using git bisect. See http://robots.thoughtbot.com/git-bisect git bisect start

git bisect good <sha-of-good-commit>

git bisect bad <sha-of-bad-commit>

git bisect run rspec spec/features/my_broken_spec.rb #To automate the bisect feature.

Log

To view recent commit on the current branch with each commit on one line git log --pretty=oneline

git ref log
View changes in one branch that do not exist in the other git log branch1 --not branch2
You can use the -- option in git log to see the commit history for a file, even if you have deleted the file git log -- [file_path]

See http://www.vogella.com/tutorials/Git/article.html#retrievefiles_finddeletedfile

You can use the above to find the commit which deleted a file and the browse the code at that commit in github.

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heroku-cheatsheet.md

Heroku:

To push develop to heroku

git push heroku develop:master
Add a remote to heroku repo url

heroku git:remote -a appname
Get a local dump for a pg database on heroku:

curl -o latest.dump $(heroku pgbackups:url)
Get pgbackup url

heroku pgbackups:url
Restore pg database from a url:
- NOTE: If you are going to restore a whole database from a dump, it makes sense to first clobber the existing one using heroku pg:reset. You can potentially hit some migratino problems otherwise.
heroku pgbackups:restore CRIMSON 'http://s3.url.com' --remote staging
To drop / reset the database

heroku pg:reset DATABASE
Deleting precompiled assets to force all assets to get precompiled again

heroku repo:purge_cache -a <appname>
- you need the heroku repo plugin to do that

If you have the following errors when pushing to heroku:

error: RPC failed; HTTP 500 curl 22 The requested URL returned error: 500 Internal Server Error

use heroku repo:reset -a <appname>

See running sql statements on the database:

heroku pg:ps --app dg-api-production

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node-cheatsheet.md

Node and npm

Upgrading npm

[sudo] npm i -g npm
To make sure my local npm files are in alignment with the the files in the respository:
```
npm i -g npm
rm -rf node_modules/
npm i
```
- To install a package to a specific version and update package.json and package-lock.json see following example:
```
  npm install eslint@4.18.2
```
Learn more about --save and --save-dev to make updates locally to node_modules when running the aforementioned command.
- Audit security issues:
```
npm audit
```
To fix security issues use
```
npm audit fix
```
- Running eslint I had trouble running eslint using npm run eslint. I also had trouble runniing it with ./node_modules//bin/eslint . .
I had to run it using ./node_modules/bin/eslint app/ --ext es6.

3k3:3

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postgresql.md

Listing all tables

\d
Listing all users

\du OR \du+

The use of + adds a description of every user. You can also list users by querying the pg_catalog.pg_user table.

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pry-cheatsheet.md

PRY

ls (list methods) in self
ls —grep finds specific names
cd <object> cds into the object... ie that is the new self.
? (show-doc) Class#method / object.method
$ (show-method) Class#method / object.method
next (next line without stepping through function calls)
step (next line respecting function call)
play -l 6 (play line number 6... same as copyig and pasting that line)
edit (opens up the editor to edit the file) / edit -m (edit current method)
edit <method> edits the specific method
try-again (I think that is a part of pry-rescue which re-runs the specific failing? test or rails request)
break <method> break on the method
break -d 1 disable first breakpoint.
up / down (go and and down the call stack)
whereami (get information on where you are in the call stack)
_ex_ recently raised exception
_file_ (last required file)
binding.pry open pry within the current binding
_ex_.bractrace gives backtrace of the exception
wtf gives first five lines of the backtrace
wtf??? with increasing question marks gives increasing lines of backtrace.
exit-program exit all future breakpoints and the current running process.

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rails-cheetsheet.md

Bundler

Find inverse dependencies of a gem gem dependency <gemname> --reverse-dependencie
Edit installed gem in bundler

export BUNDLER_EDITOR=mvim && bundle open gemname
List out all the gems that will be updated if you run the bundle update command: bundle outdated
clean out all the unrequired gems under certain conditions.

bundle clean

Rake

List all possible rake tasks rake -T
To see routes: bundle exec rake routes
To list all the middleware bundle exec rake middleware

Rails

Start the rails server with debugger options

rails server --debugger
To test out some code without changing any data:

rails console --sandbox Any modifications that are made will be rolled back on exit.

Rails Generators

igrations:

To migrate:

rake db:migrate
To go back one migration:

rake db:rollback
To go back two migrations:

rake db:rollback STEP=2
Adding a column

rails generate migration AddActiveToNews active:boolean
Adding paperclip columns:

rails generate migration add_paperclip_columns_to_my_model image_file_name:string image_content_type:string image_file_size:integer image_updated_at:datetime
Mailers:

To automatically generate mailer and associated directories

rails generate mailer MyMailer

RubyGems

Create a gem executible gem build scriptura.gemspec
Publish a gem gem push <gem-file-name example gem push scriptura-0.0.3.gem

HTTParty

Making an Http get request using tokens:

 HTTParty.get("http://api.local.dg:3000/v0/collections/wjfmvjzo/resources", :query => {"page[number]" => '1', "page[size]" => '366'}, :headers => {'Authorization' => "Token token=\"api-token\""})

Local bootstrap:
Use: FILE=/Users/gagan/projects/desiring-god-new/db/dumps/dg_production_a926_20161228T103557-0600.dump rake db:bootstrap

RVM

To get the information about all possibilities of using the rvm command:

rvm
To see a list of installed rubies:

rvm list; #My terminal does not show the system installed ruby with this command
To go to the system installed version of rvm

rvm system
To make system version of ruby default ,

rvm system --default
to uninstall rvm

rvm implode apparently

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unix-cheatsheet.md

Unix

Grep

Excluding directories in your grep

When it is in the current directory:

grep -r -F "Date" . --exclude-dir={.git,tmp,log,vendor}

When it is in the tree but not the current directory

grep -r -F "Date" . --exclude="*spec/cassettes*"

Curl

Only get headers from the url

curl -s -D - https://www.desiringgod.org -o /dev/null

Only get headers from the url behind http digest auth

curl -s -D - http://staging.desiringgod.org -o /dev/null --digest -u <username>

Then enter password. or try:

curl -s -D - https://dgbeta.org -o /dev/null --digest -u <username>:<password>

Bash

Run command multiple times: for i in {1..10}; do commandNameHere; done http://www.cyberciti.biz/faq/bsd-appleosx-linux-bash-shell-run-command-n-times/

find and replace

find and replace recursively within a folder:

perl -p -i -e 's/oldstring/newstring/g' `find ./ -name '*.rb'` or

perl -p -i -e 's/oldstring/newstring/g' `grep -ril oldstring *`

Replace backreference with lower case:

\l change the case
\L also changes the case

Using a variable to replace existing matching expression

Following script changes ResourceType.find('Article), or ResourceType.find('Books') to ResourceType.find('articles') ResourceType.find('books') perl -p -i -e "s/ResourceType.find\('(.)/ResourceType.find('\l\$1/g" spec/redirectors/v_2014/resource_library_spec.rb
Following script replaces %r{<something>} to hello(<something>) in lib/scripts
perl -p -i -e "s/%r\{(.*)}/hello(\$1)/g" lib/scripts/

Looping

Repeat command multiple times over

for i in {1..10}; do rspec spec/features/resource_library/sermons_spec.rb; done

Renaming files in a pattern using unix

for f in *worker* ; do mv "$f" "echo $f | sed s/worker/job/"; done

Renaming files in a pattern using ruby

> folder_path = '/Users/gagan/projects/desiring-god-new/app/jobs'
> Dir.glob(folder_path + '/*').each do |f|
>     File.rename(f, folder_path + '/' + File.basename(f).gsub('worker', 'job') + File.extname(f))
> end

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