Best Practices for Ruby Expressions

 Ruby Expressions | Best Practices

Writing ruby expressions in a good/optimized way doesn't only increases the efficiency of the code but also increases the code readability. Here are some good way to write ruby expressions.

1. Use of unless
If we are checking an if condition that do not have else part than we should use unless.
example:

# Bad code
if ! names.empty?
  puts names
end

# Good code
unless names.empty?
  puts names
end

2.  Nil condition
If anything that returns nil. So instead of checking for nil we can directly use if condition on it, as ruby considers nil as false.
example:

# Bad code
if attachment.file_path != nil
  puts "we have a path"
end

# Good code
if attachment.file_path
  puts "we have a path"
end

3. Not everything evaluates to false
For example "" is treated as true,  0 is treated as true, [] empty array is treated as true.
example:

# Bad code
unless name.length
  puts"name is required"
end

Here name.length is never going to be false as 0 would be considered as true. So we need to be careful about this.

4. Inline conditionals
Inline conditional should be used for better readability.
example:

# Bad code
if password.length < 8
  puts "short password"
end
unless username
  puts "username not set"
end

# Good code
puts "short password" if password.length <8
puts "username not set" unless username

6. Using short-circuit assignment 
We can use || operator for short-circuit assignment. In the example below if the first assignment before || is nil than only it will go for the other part. For example in first one, the nil is encountered and than it checks for the other one i.e. 1, it assigns 1 to result. In second one, as soon as it gets 1, it doesn't check of nil. In the third one, as soon as it gets 1, it doesn't check for 2 and assigns 1 to result.

result = nil || 1        # output 1
result = 1 || nil       # output 1
result = 1 || 2          # output 1

If the first part of the expression is evaluated to true than second part is not even going to get touched.
example: check of the names, if there are no names than set the names to an empty array

# Bad code
names = Users.names
names = [] unless names

# Good code
names = User.names || []