From: shevegen@... Date: 2018-01-15T15:02:39+00:00 Subject: [ruby-core:84874] [Ruby trunk Bug#14360] Regression CSV#open method for writing from Ruby 2.4.3 to 2.5.0 Issue #14360 has been updated by shevegen (Robert A. Heiler). > This issue is also open in its repository because it's not clear to me > where is the appropriate place to open the issue Don't worry - the tracker here is still the official bug/feature/misc tracker for the ruby language. Github issues are secondary and often primarily useful for patchsets/pull requests. The ruby core team often encourages people to write an issue tracker here at bugs.ruby-lang.org rather than just on github alone. To the issue at hand, I know way too little to really meaningfully comment on it but I think that this may indeed be a regression. At the least I can not think of a deliberate change to have different behaviour there. https://www.ruby-lang.org/en/news/2017/12/25/ruby-2-5-0-released/ does not list any notable change in the CSV module. Possibly a test can ensure the functionality to remain the same (if it is a regression) in this context. ---------------------------------------- Bug #14360: Regression CSV#open method for writing from Ruby 2.4.3 to 2.5.0 https://bugs.ruby-lang.org/issues/14360#change-69583 * Author: arturoherrero (Arturo Herrero) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17] * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- I have noticed a different behaviour between Ruby <= 2.4.3 and Ruby 2.5.0 for the `#open` method. This issue is also open in its repository because it's not clear to me where is the appropriate place to open the issue, https://github.com/ruby/csv/issues/17 If you create an empty file for writing and you are not writing any line in that CSV file, Ruby <= 2.4.3 doesn't write anything (an empty file) but Ruby 2.5.0 writes the headers. ### Ruby <= 2.4.3 ```shell $ ruby -v ruby 2.4.3p205 (2017-12-14 revision 61247) [x86_64-darwin17] ``` ```ruby $ irb irb(main):001:0> require "csv" => true irb(main):002:0> CSV.open("ruby-2.4.3.csv", "wb", headers: ["name", "surname"], write_headers: true) { } => nil irb(main):003:0> `cat ruby-2.4.3.csv` => "" ``` ### Ruby 2.5.0 ```shell $ ruby -v ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17] ``` ```ruby $ irb irb(main):001:0> require "csv" => true irb(main):002:0> CSV.open("ruby-2.5.0.csv", "wb", headers: ["name", "surname"], write_headers: true) { } => nil irb(main):003:0> `cat ruby-2.5.0.csv` => "name,surname\n" ``` --- In the examples, I'm using an empty block but in a real application probably you will have an `if` statement, something like this: ```ruby CSV.open(...) do |csv| csv << "hello" if condition end ``` -- https://bugs.ruby-lang.org/ Unsubscribe: