Avoid ruby 2.4+ methods

[kachick]

erb/.github/workflows/test.yml

Lines 9 to 15 in 9cef102

	matrix:
	ruby:
	- '2.5'
	- '2.6'
	- '2.7'
	- '3.0'
	- head

erb/erb.gemspec

Line 17 in 9cef102

spec.required_ruby_version = Gem::Requirement.new('>= 2.3.0')

Currently supporting as 2.3+, but testing in 2.5+
This does not run from some reasons.

• Using String#match?
• Using String#unpack1

Both are not in ruby 2.3

So I think need some changes.

• Clarify to support 2.4+ or 2.5+
• Avoid 2.4+ feature

This PR aims Avoid 2.4+ feature, but some test still fail on rubylang/ruby:2.3.8-bionic even after applied this patch.

Error: test_invalid_trim_mode(TestERBCore): NoMethodError: undefined method `diff' for #<TestERBCore:0x000055c07dff2150>                                                                                         [35/1068]
/usr/src/test/lib/core_assertions.rb:509:in `block in assert_warning'
/usr/src/test/lib/core_assertions.rb:21:in `block in message'
/usr/src/test/lib/core_assertions.rb:510:in `assert_warning'
/usr/src/test/erb/test_erb.rb:239:in `test_invalid_trim_mode'
     236:   end
     237:
     238:   def test_invalid_trim_mode
  => 239:     assert_warning(/#{__FILE__}:#{__LINE__ + 1}/) do
     240:       @erb.new("", trim_mode: 'abc-def')
     241:     end                                                                                                                                                                                                              242:

Failure:                                                                                                                                                                                                         [20/1068]
  pid 18 exit 0
  | warning: -S option of erb command is deprecated. Please do not use this.
  | Passing safe_level with the 2nd argument of ERB.new is deprecated. Do not use it, and specify other arguments as keyword arguments.
  | {:uplevel=>1}
  .

  1. [2/2] Assertion for "stderr"
     | Expected /\n.+\/libexec\/erb:\d+: warning: Passing safe_level with the 2nd argument of ERB\.new is deprecated\. Do not use it, and specify other arguments as keyword arguments\.\n/
     | to match
     |   "\n"+
     |   "Passing safe_level with the 2nd argument of ERB.new is deprecated. Do not use it, and specify other arguments as keyword arguments.\n"+
     |   "{:uplevel=>1}\n"
     | after 1 patterns with 72 characters.
     | <false> is not true.
  <false> is not true.
test_deprecated_option(TestErbCommand)
/usr/src/test/lib/core_assertions.rb:617:in `assert_all_assertions'
/usr/src/test/lib/core_assertions.rb:71:in `assert_in_out_err'
/usr/src/test/erb/test_erb_command.rb:25:in `test_deprecated_option'
     22:       "warning: -S option of erb command is deprecated. Please do not use this.",
     23:       /\n.+\/libexec\/erb:\d+: warning: Passing safe_level with the 2nd argument of ERB\.new is deprecated\. Do not use it, and specify other arguments as keyword arguments\.\n/,
     24:     ]

I'm not sure the root cause.
But this change might be work on Ruby 2.3, Iguess.

I'll create another PR for Clarify to support 2.4+ or 2.5+ .

[k0kubun]

Thanks for providing two different fix patterns. Looks like default gems, in general, seem to respect Ruby's EOL cycles. Since erb.gem has been released very recently and it has been broken, dropping the support should have no practical impact, and this is reversing [Feature 13943] too. So I'd like to accept the other patch #3.

[kachick]

Oh I didn't know the existing ruby-lang issue, Thank you for letting me know!

👍 to #3 direction