TILs - Fueling Curiosity, One Insight at a Time

always use default props while writing react component, reduces the number of unexpected bugs which are hard to reproduce.

a tags without an href are not links, they are placeholders for links. Also, capybara only click on links which have the href attribute.

Difference between usage of size/count/length when dealing with ActiveRecord::Relations and got rid of many COUNT(*) queries. Good article on the same - http://work.stevegrossi.com/2015/04/25/how-to-count-with-activerecord/

Postgres VACUUM [https://www.postgresql.org/docs/9.1/static/sql-vacuum.html] - It reclaims storage occupied by dead tuples.

Rspec's subject is a special variable that refers to the object being tested. It's instantiated implicitly but can also be done explicitly. Handy to be used with shoulda matchers.

In Tmux, prefix+t shows the current time in big font size

about StringIO http://ruby-doc.org/stdlib-1.9.3/libdoc/stringio/rdoc/StringIO.html so useful in certain cases

looping through a collection of records in database using methods like all is very inefficient (it tries to instantiate all objects at once) and should resort to batch processing methods eg: find_each.

ansible lets u use ansible_distribution ( values : Ubuntu, CentOS etc), ansible_distribution_release (values : xenial, precise etc) to write dist specific commands

There is a global location for git ignore *nix - ~/.config/git/ignore

open chrome devtools, press cmd(ctrl) + shift + p and type show coverage and press enter, once you reload the page you can see the amount of JS fetched and how much is actually getting used on that page

ruby has a permutation method for Array. https://apidock.com/ruby/Array/permutation

Array.from() takes a second argument which is a map. Example: Array.from(Array(10), (element, index) => //some logic to fill the array)

this seems a pretty cool library http://shrinerb.com/

Rails console does lazy connection to database and this behaviour can be changed with by adding ActiveRecord::Base.connection to console config block.

"localization" referred as "l10n", and "internationalization" referred as "i18n". cause,
l10n => "l" in between 10chars(o, c, a, l, i, z, a, t, i, o) and then "n"
i18n => "i" in between 18chars and then "n"
Also Globalization (g11n), Localizability (l12y).
I didnt knew, never noticed, and I feel stupid now :P

[...Array(100).keys()] will return a range from 0 to 100

long read on load balancing https://blog.envoyproxy.io/introduction-to-modern-network-load-balancing-and-proxying-a57f6ff80236

more info on proxy javascript objects here https://docs.microsoft.com/en-us/scripting/javascript/reference/proxy-object-javascript

in es6 you can now proxy your object's operation like get, set etc. All you need to do it create a proxy on a object like const proxyObj = new Proxy(initialObj, handler) the initial object is the object that you want to create proxy for and handler object is the place where you override object's method like get and set.