Ruby replacing entire file instead of appending to it

Question

The following ruby code is replacing the entire contents of the file. How can I just append to the end of the file and keep it's existing contents intact?

File.open("db/seeds.rb", "w") do |f|
    f.write "Blog::Engine.load_seed"
end

Answer 1

Use append mode ("a"):

File.open("db/seeds.rb", "a") do |f|

Here is a link to the docs, on the different modes you can specify when opening a file.

Answer 2

Write in append mode 'a'

File.write('db/seeds.rb', "Blog::Engine.load_seed", nil , mode: 'a')