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Douglas Teoh dteoh

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dteoh / mysql2-gem-install.md
Created Nov 22, 2019
Installing mysql2 gem
View mysql2-gem-install.md

Installing mysql2 gem

This is always an annoying process, especially when you are setting up a new computer. I assume you are using macOS + homebrew. I also assume that you want to run an older version of MySQL (although the instructions should be adaptable).

Installing MySQL

$ brew install mysql@5.7 # change the version if needed
@dteoh
dteoh / put_post_json_rails_5_integration_test.md
Created Jul 12, 2016
PUT or POST JSON in a Rails 5 ActionDispatch::IntegrationTest
View put_post_json_rails_5_integration_test.md

In Rails 5, the preferred base class for testing controllers is ActionDispatch::IntegrationTest.

If you have an API that receives parameters as JSON request bodies, here are some helper methods to facilitate testing:

class ActionDispatch::IntegrationTest
  def put_json(path, obj)
    put path, params: obj.to_json, headers: { 'CONTENT_TYPE' => 'application/json' }
  end
@dteoh
dteoh / .gitconfig
Created Mar 17, 2019
Use Neovim as git mergetool
View .gitconfig
[merge]
tool = vimdiff
[mergetool]
keepBackup = false
[mergetool "vimdiff"]
cmd = nvim -d $LOCAL $REMOTE $MERGED -c '$wincmd w' -c 'wincmd J'
@dteoh
dteoh / unused-this.md
Last active Jun 2, 2020
Solving "unused variable this." warnings when using ReasonML objects
View unused-this.md

unused variable this

You can create [objects in ReasonML][1]. For example:

let document = {
  pub title = "My Treatise";
  pub contents = "<a lot of words>"
};
@dteoh
dteoh / rspec_rails_set_session.md
Created May 29, 2020
Setting session variables in an RSpec Rails request spec
View rspec_rails_set_session.md

Setting session variables in an RSpec Rails request spec

You are writing a spec with type: :request, i.e. an integration spec instead of a controller spec. Integration specs are wrappers around Rails' ActionDispatch::IntegrationTest class. I usually write controller tests using this instead of type: :controller, mainly because it exercises more of the request and response handling stack. So instead of writing something like get :index to start the request, you would write get books_path or similar.

One of the issues with using type: :request is that you lose the ability to

@dteoh
dteoh / arel_select_star_from_table.rb
Last active Dec 2, 2019
Select all columns of an Arel table
View arel_select_star_from_table.rb
users = User.arel_table
query = users.project(users[Arel.star])
@dteoh
dteoh / custom_ar_relation_relay_connection.rb
Last active Oct 28, 2019
GrapQL Ruby: Custom Relay connection class for ActiveRecord::Relation objects
View custom_ar_relation_relay_connection.rb
# This custom relay connection class exists because the built-in connection
# class is broken when max_page_size is used.
#
# See: https://github.com/rmosolgo/graphql-ruby/issues/1109
class CustomArRelationRelayConnection < GraphQL::Relay::BaseConnection
def cursor_from_node(item)
cursor_col = item.class.implicit_order_column
encode(item.send(cursor_col).to_s)
end
@dteoh
dteoh / dictionary.md
Created Oct 23, 2019
Display dictionary definition on macOS
View dictionary.md
  1. Move mouse cursor to point at a word
  2. Press Command + Ctrl + D
@dteoh
dteoh / cors-curl.md
Created Sep 26, 2019
Check CORS headers with `curl`
View cors-curl.md
$ curl -X OPTIONS -H “Origin: REQUESTER-DOMAIN.com” -H “Access-Control-Request-Method: GET“ -s -v <TARGET URL HERE> 1> /dev/null
@dteoh
dteoh / macos_no_sleep.md
Created Feb 23, 2017
Preventing macOS from sleeping
View macos_no_sleep.md

There is a built-in command line utility caffeinate that can be used to prevent macOS from sleeping.

To prevent macOS from sleeping before a process with given PID exits:

$ caffeinate -w PID

To prevent macOS from sleeping for the next N seconds:

You can’t perform that action at this time.