Rails console initiates a "Display all 573 possibilities? (y or n)" dialog when I paste a multiline instruction into it

Question

I am copying the following snippet from my text-editor to my rails console:

request = Typhoeus::Request.new(
"https://track.customer.io/api/v1/customers/4", 
ssl_verifypeer: false,
method: :put,
headers: {
    "Content-Type" => "application/json",
    "User-Agent" => "#{Rails.configuration.customerio[:site_id]}:#{Rails.configuration.customerio[:api_key]}"},
body: '{
"email":"[email protected]", 
"name":"Name is here",
"id":"4",
"created_at":"#{Time.now}"}')

When I copy it all as one line:

request = Typhoeus::Request.new("https://track.customer.io/api/v1/customers/4", ssl_verifypeer: false,method: :put,headers: {"Content-Type" => "application/json","User-Agent" => "#{Rails.configuration.customerio[:site_id]}:#{Rails.configuration.customerio[:api_key]}"},body: '{"email":"[email protected]", "name":"Name is here","id":"4","created_at":"#{Time.now}"}')

Then console returns with a standard response:

 => #<Typhoeus::Request:0x00000101c517a8 @base_url="https://track.customer.io/api/v1/customers/4", @original_options=...

However, if I copy it line-by-line (as I did in the first code snippet) I get a strange error. The console asks me if I want to display all possibilities, as if I'm searching a directory or making a search query midway through the paste. Check it out:

1.9.3p393 :091 > request = Typhoeus::Request.new(
1.9.3p393 :092 >     "https://track.customer.io/api/v1/customers/4", 
1.9.3p393 :093 >     ssl_verifypeer: false,
1.9.3p393 :094 >     method: :put,
1.9.3p393 :095 >     headers: {
1.9.3p393 :096 >
Display all 573 possibilities? (y or n) 
1.9.3p393 :096 >       "Content-Type" => "application/json",
1.9.3p393 :097 >
Display all 573 possibilities? (y or n) 
1.9.3p393 :097 >       "User-Agent" => "#{Rails.configuration.customerio[:site_id]}:#{Rails.configuration.customerio[:api_key]}"},
1.9.3p393 :098 >     body: '{
1.9.3p393 :099'> "email":"[email protected]", 
1.9.3p393 :100'> "name":"Name is here",
1.9.3p393 :101'> "id":"4",
1.9.3p393 :102'> "created_at":"#{Time.now}"}')

If I select n both times, the request is created normally. However, if I select y, it lists 573 items, most of which I've put into this pastie: http://pastie.org/private/ksgzqhd50mvdi0t6cqe8g

Do you know what these results are and, more importantly, why they're being prompted at this strange time?

Answer 1

Sounds like the source you're copying the code from has two tab characters where "Content-Type"... and "User-Agent"... are indented. Two tab characters will invoke the auto-completion list in the console (the prompt you're seeing is when the number of possible completions exceeds a certain threshold).

Notice that if you copy and paste it from your own StackOverflow post you shouldn't see the auto-complete prompts because it is using spaces for the indentation and not tabs.

Edit:

To confirm my suspicion, turn on "show whitespace" in your editor to see if there are tab characters at the start of those two lines.

Personal opinion: I would recommend that you configure your editor to insert spaces for tab key presses if you haven't already done so. Tabs are the devil's whitespace :).