Welcome! ❤️

In this workshop:

• Why Rails?
• Some Ruby you probably haven't seen yet
• Writing production code

What makes Rails the best choice?

1. Ruby + Rails = ❤️

2. Convention over configuration

3. Fantastic communities

Rails isn't perfect!

Any questions? 🤔

Enough Rails, let's talk Rubyisms

Good

'Hello, Sean!'

"Hello, #{name}!"

trees = ['chestnut', 'mahogany', 'pine']

trees = %w[chestnut mahogany pine]

old_hash = { :apple => 'fruit', :banana => 'vegetable' }

new_hash = { apple: 'fruit', banana: 'vegetable' }

[[:apple, 'fruit'], [:banana, 'vegetable']].to_h
=> { :apple => 'fruit', :banana => 'vegetable' }

Identical!

1. { :a => 'b' }

2. { a: 'b' }

3. [[:a, 'b']].to_h

players = [...]
players.each do |player|
  player.delete
end

players.each { |player| player.delete }

players.each(&:delete)

Remember that function calls in Ruby do not have to have parentheses

players.each &:delete

But you should always use parentheses when chaining

Player.find_by(name: 'Sean').delete

• if and unless
• Guard statements
• Bang and question mark methods
• Hashes as parameters
• Symbols
• DSLs
• Different kinds of loops

Some common Ruby pitfalls...

Can you spot what's wrong?

a = 0
loop do
  a++
  break if a == 10
end
=> undefined method '+@' for nil:NilClass (NoMethodError)

a = 1
a += 1
puts a
=> 2

Can you spot what's wrong?

a = false
b = true
if a
  puts a
else if b
  puts b
end
=> syntax error, unexpected end-of-input

a = false
b = true
if a
  puts a
elsif b
  puts b
end
=> true

Why is the output unexpected?

[0..2].each do |i|
  puts "i = #{i}"
end
=> "i = 0..2"

(0..2).each do |i|
  puts "i = #{i}"
end
=> "i = 0"
=> "i = 1"
=> "i = 2"

Any questions? 🤔

Writing production level code

Production is scary!

How can we mitigate the badness?

Observe! The 6 production commandments

1. Write tests and run them before committing

test "username should be present" do
  blank_username = Player.new(username: '')
  assert_not blank_username.valid?
end

2. Use branches, and keep their contents atomic

3. Run Rubocop as much as possible

4. Don't fight the CI (continuous integration)

5. Never push changes directly to production

6. Review pull requests

In summary:

1. Write tests
2. Use branches
3. Run Rubocop
4. Listen to CI
5. Never push to production (directly)
6. Peer reviews

Any closing questions? 🤔