Rails- upgrading to ruby 2.2.2 - no implicit conversion of Array into String (TypeError)

Question

very new to ruby and rails.. Ive been working on a project, that simply reads in files and parses them to store into a database. Project was running fine, however running the code after an update to ruby 2.2.2 , I received an error that wasn't previously there:

in `foreach': no implicit conversion of Array into String (TypeError)

Here is the snippet of the foreach thats causing an error: (let me know if more code is necessary).

def parse(file_name)
  File.foreach(file_name).with_index do |line, line_num|
    puts "\nLine #{line_num}: #{line}"

Does anyone know whats going on? Thank you

EDIT: Sorry it was a snippet! Im calling this ruby code into my rails Test called "parse_log_file_test"

require File.dirname(__FILE__) + '/../test_helper'

class ParseLogFileTest < ActiveSupport::TestCase

  filename = Array.new

  Dir.glob('database/oag-logs/*.log').each do |log_file|

    filename.push(log_file)

  end

  parser = ParseLogFile.new

  parser.parse(filename)

  test 'parse' do
    parser = ParseLogFile.new

    filename.each do |log_file|

      begin

        parser.parse(log_file)
      rescue

        puts"ERROR: Unable to parse line #{log_file}"

      end
    end
    assert true
  end
end

Answer 1

我猜想您省略了函数的end ，但是如果您没有它，那就需要它。

Answer 2

This error indicates that the argument passed to parse as file_name is an array instead of a string.

However, if that's the case, it fails the same on eg Ruby 1.8.4:

File.foreach([]).with_index do |line, line_num|
  puts "\nLine #{line_num}: #{line}"
end

Output:

TypeError: can't convert Array into String
    from (irb):1:in `foreach'
    from (irb):1:in `with_index'
    from (irb):1
    from :0

Thus my guess is that the code that produces the value you pass to parse returned a string in your previous Ruby version and returns an array in 2.2.2.

In your case, the error is caused by the first invocation of parser.parse(...) , right above the test 'parse' do line, not by the invocation inside the test method. I guess you put that invocation there after the migration, probably to debug a problem. But you are passing a different argument to the first invocation than to the invocation inside the test method, so it fails for a different reason than the one in the test method.

To see what Error is caused inside your test, simply remove the lines

      rescue

        puts"ERROR: Unable to parse line #{log_file}"

(Keep the end or you'll have to remove the begin , too.)

This way, an Error will hit the test runner, which will usually display it including message and stack trace.

Answer 3

Agreed with the poster above that you are most likely missing quotation marks. It should have nothing to do with 2.2.2 though, probably you are copy-pastying your file name differently this time around.

Answer 4

So apparently this is an issue with upgrading to ruby 2.2.2 on windows. After getting past this error, I only encountered more errors.. nokogiri..etc

I have recently got a mac and the errors went away.