Why is this string value converted to an array? - ruby

Question

I have the following function:
def parse_var(var)
value = instance_variable_get(var)
puts(value)
puts(value.to_s)
value.is_a?(Numeric) ? value.to_s : "\"#{value}\""
end
Variables of certain form are converted into an array when they are interpolated. In the above function, when value equals [phone] x01024, value.to_s comes out to be ["[phone] x01024", nil]. The same thing also happens when I try "#{value}".
What is causing this?
Here's the context of the code in question:
Entity.rb (context of above code)
require 'securerandom'
# Entity.rb
class Entity
def initialize
generate_uuid
end
def to_cypher
first_char = self.class.name.chr.downcase
"MERGE (#{first_char}:#{self.class.name} {#{attrs_to_cypher.join(', ')}}) RETURN #{first_char};"
end
protected
def rand_bool
[true, false].sample
end
private
def attrs_to_cypher
self.instance_variables.map do |var|
"#{camelize(var.to_s[1..-1])}:#{parse_var(var)}"
end
end
def generate_uuid
#uuid = SecureRandom.uuid
end
def parse_var(var)
value = instance_variable_get(var)
puts(value)
puts(value.to_s)
value.is_a?(Numeric) ? value.to_s : "\"#{value}\""
end
def camelize(s)
(s == "uuid") ? "UUID" : s.downcase.split('_').map(&:capitalize).join
end
end
PhoneNumber.rb (where the value is coming from)
require 'faker'
require_relative 'Entity'
# PhoneNumber.rb
class PhoneNumber < Entity
def initialize(**opts)
super()
#type = opts[:type] || rand_bool ? "cell" : "home"
#number = opts[:number] || #type == "cell" ? Faker::PhoneNumber.cell_phone : Faker::PhoneNumber.phone_number,
#country_code = opts[:country_code] || nil
#area_code = opts[:area_code] || nil
end
end

Answer 1

The following line of code is causing a couple of issues
#number = opts[:number] || #type == "cell" ? Faker::PhoneNumber.cell_phone : Faker::PhoneNumber.phone_number,
First, the || operator has a higher precedence than the ? operator, so it actually looks like:
#number = (opts[:number] || #type == "cell") ? Faker::PhoneNumber.cell_phone : Faker::PhoneNumber.phone_number,
and you probably were wanting this:
#number = opts[:number] || (#type == "cell" ? Faker::PhoneNumber.cell_phone : Faker::PhoneNumber.phone_number),
As it stands, it doesn't matter what you pass into opts[:number], you'll always get a Faker::PhoneNumber assigned. (The line above, assigning type, looks like it would have this same precedence issue)
Second, you have a stray comma at the end of the line. This is turning the entire line into the first element of an array, and doesn't interfere with assigning the variable on the next line, so it's hard to catch:
opts = { number: '123' }
type = "cell"
number = opts[:number] || type == "cell" ? "truthy" : "falsey",
country = "some value"
p number # => ["truthy", "some value"]
p country # => "some value"

Answer 2

Your variable contains ["[phone] x01024", nil], not a string. You rely on puts(value) output to determine it’s value which is plain wrong:
puts ["[phone] x01024", nil]
#⇒ [phone] x01024
#
puts(nil) returns an empty string, making you think the original value is a string.
To overcome this issue you might:
value = [*value].compact.join