Method: Rack::Lint#check_headers

Defined in:

lib/rack/lint.rb

#check_headers(header) ⇒ Object

The Headers

# File 'lib/rack/lint.rb', line 402

def check_headers(header)
  ## The header must respond to +each+, and yield values of key and value.
  assert("headers object should respond to #each, but doesn't (got #{header.class} as headers)") {
     header.respond_to? :each
  }
  header.each { |key, value|
    ## The header keys must be Strings.
    assert("header key must be a string, was #{key.class}") {
      key.instance_of? String
    }
    ## The header must not contain a +Status+ key,
    assert("header must not contain Status") { key.downcase != "status" }
    ## contain keys with <tt>:</tt> or newlines in their name,
    assert("header names must not contain : or \\n") { key !~ /[:\n]/ }
    ## contain keys names that end in <tt>-</tt> or <tt>_</tt>,
    assert("header names must not end in - or _") { key !~ /[-_]\z/ }
    ## but only contain keys that consist of
    ## letters, digits, <tt>_</tt> or <tt>-</tt> and start with a letter.
    assert("invalid header name: #{key}") { key =~ /\A[a-zA-Z][a-zA-Z0-9_-]*\z/ }

    ## The values of the header must be Strings,
    assert("a header value must be a String, but the value of " +
      "'#{key}' is a #{value.class}") { value.kind_of? String }
    ## consisting of lines (for multiple header values, e.g. multiple
    ## <tt>Set-Cookie</tt> values) seperated by "\n".
    value.split("\n").each { |item|
      ## The lines must not contain characters below 037.
      assert("invalid header value #{key}: #{item.inspect}") {
        item !~ /[\000-\037]/
      }
    }
  }
end