I have this method in my models/images.rb model. I am starting with testing and having a hard time coming up with tests for it. Would appreciate your help.
def self.tags
t = "db/data.csv"
@arr = []
csvdata = CSV.read(t)
csvdata.shift
csvdata.each do |row|
row.each_with_index do |l, i|
unless l.nil?
@arr << l
end
end
end
@arr
end
First off a word of advice - CSV is probably the worst imaginable data format and is best avoided unless absolutely unavoidable - like if the client insists that manipulating data in MS Excel is a good idea (it is not).
If you have to use CSV don't use a method name like .tags which can confused for a regular ActiveRecord relation.
Testing methods that read from the file system can be quite difficult.
To start with you might want to alter the signature of the method so that you can pass a file path.
def self.tags(file = "db/data.csv")
# ...
end
That way you can pass a fixture file so that you can test it deterministically.
RSpec.describe Image do
describe "tags" do
let(:file) { Rails.root.join('spec', 'support', 'fixtures', 'tags.csv') }
it 'returns an array' do
expect(Image.tags(file)).to eq [ { foo: 'bar' }, { foo: 'baz' } ]
end
end
end
However your method is very ideosyncratic -
def self.tags
t = "db/data.csv"
@arr = []
self.tags makes it a class method yet you are declaring @arr as an instance variable.
Additionally Ruby's enumerable module provides so many methods for manipulating arrays that using an outer variable in a loop is not needed.
def self.tags(file = "db/data.csv")
csv_data = CSV.read(file)
csv_data.shift
csv_data.compact # removes nil elements
end
