Ruby-on-rails – Which Ruby on Rails is compatible with which Ruby version

rubyruby-on-rails

I have an old 2.1.1 Ruby on Rails application, with the system upgraded to use Ruby 1.8.7. It originally used 1.8.5 or so.

I want to upgrade it to Ruby 1.9.x for performance reasons, and possibly to a newer Ruby on Rails as well.

I cannot find any easy chart of compatibility between different Ruby versions and Ruby on Rails versions.

Will 2.1.1 work with Ruby 1.9.x? If not, how far do I need to upgrade it first, and what kind of issues am I likely to encounter? My application does complicated things to database layer, but the rest is fairly straightforward.

Best Answer

This is an old question, but the fact that rails is tested against a version of ruby is a good indication that it should work on that version of ruby.

Since 9th April 2019, stable branches of Rails use Buildkite for automated testing, and the list of tested ruby versions, by rails branch, is:

Rails 6.1

>= 2.5.0

Rails 6.0

>= 2.5.0

Rails 5.2

>= 2.2.2
< 2.7 (see https://github.com/rails/rails/issues/38426)

Rails 5.1

>= 2.2.2

Rails 5.0

>= 2.2.2

Rails 4.2

>= 1.9.3

Rails 4.1

>= 1.9.3

Prior to 9th April 2019, stable branches of Rails since 3.0 use travis-ci for automated testing, and the list of tested ruby versions, by rails branch, is:

Rails 3.0

1.8.7
1.9.2
1.9.3

Rails 3.1

1.8.7
1.9.2
1.9.3

Rails 3.2

1.8.7
1.9.2
1.9.3
2.0.0
2.1.8
2.2.6
2.3.3

Rails 4.0

1.9.3
2.0.0
2.1
2.2

Rails 4.1

1.9.3
2.0.0
2.1
2.2.4
2.3.0

Rails 4.2

1.9.3
2.0.0-p648
2.1.10
2.2.10
2.3.8
2.4.5

Rails 5.0

2.2.10
2.3.8
2.4.5

Rails 5.1

2.2.10
2.3.7
2.4.4
2.5.1

Rails 5.2

2.2.10
2.3.7
2.4.4
2.5.1

Rails 6.0

2.5.3
2.6.0

(From https://www.hmallett.co.uk/2018/08/ruby-and-ruby-on-rails-version-compatibility/)

Related Solutions

Ruby – How to call shell commands from Ruby

This explanation is based on a commented Ruby script from a friend of mine. If you want to improve the script, feel free to update it at the link.

First, note that when Ruby calls out to a shell, it typically calls /bin/sh, not Bash. Some Bash syntax is not supported by /bin/sh on all systems.

Here are ways to execute a shell script:

cmd = "echo 'hi'" # Sample string that can be used

Kernel#` , commonly called backticks – `cmd`

This is like many other languages, including Bash, PHP, and Perl.

Returns the result (i.e. standard output) of the shell command.

Docs: http://ruby-doc.org/core/Kernel.html#method-i-60
```
value = `echo 'hi'`
value = `#{cmd}`
```
Built-in syntax, %x( cmd )

Following the x character is a delimiter, which can be any character. If the delimiter is one of the characters (, [, {, or <, the literal consists of the characters up to the matching closing delimiter, taking account of nested delimiter pairs. For all other delimiters, the literal comprises the characters up to the next occurrence of the delimiter character. String interpolation #{ ... } is allowed.

Returns the result (i.e. standard output) of the shell command, just like the backticks.

Docs: https://docs.ruby-lang.org/en/master/syntax/literals_rdoc.html#label-Percent+Strings
```
value = %x( echo 'hi' )
value = %x[ #{cmd} ]
```
Kernel#system

Executes the given command in a subshell.

Returns true if the command was found and run successfully, false otherwise.

Docs: http://ruby-doc.org/core/Kernel.html#method-i-system
```
wasGood = system( "echo 'hi'" )
wasGood = system( cmd )
```
Kernel#exec

Replaces the current process by running the given external command.

Returns none, the current process is replaced and never continues.

Docs: http://ruby-doc.org/core/Kernel.html#method-i-exec
```
exec( "echo 'hi'" )
exec( cmd ) # Note: this will never be reached because of the line above
```

Here's some extra advice: $?, which is the same as $CHILD_STATUS, accesses the status of the last system executed command if you use the backticks, system() or %x{}. You can then access the exitstatus and pid properties:

$?.exitstatus

For more reading see:

Ruby-on-rails – How to “pretty” format JSON output in Ruby on Rails

Use the pretty_generate() function, built into later versions of JSON. For example:

require 'json'
my_object = { :array => [1, 2, 3, { :sample => "hash"} ], :foo => "bar" }
puts JSON.pretty_generate(my_object)

Which gets you:

{
  "array": [
    1,
    2,
    3,
    {
      "sample": "hash"
    }
  ],
  "foo": "bar"
}

Best Answer

Related Solutions

Ruby – How to call shell commands from Ruby

Ruby-on-rails – How to “pretty” format JSON output in Ruby on Rails

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