Remove open-ended and prerelease dependency warnings when building gems

In general, rubygems should provide mechanism and not policy.

Pessimistic versioning is not universally better, and in many
cases, it can cause more problems than it solves. Rubygems should
not be warning against open-ended versioning when building gems.
The majority of the default gems with dependencies do not use
pessimistic versioning, which indicates that Ruby itself
recognizes that open-ended versioning is generally better.

In some cases, depending on a prerelease gem is the only choice
other than not releasing a gem. If you are building an extension
gem for a feature in a prerelease version of another gem, then
depending on the prerelease version is the only way to ensure
a compatible dependency is installed.

Author: jeremyevans

lib/rubygems/specification_policy.rb

@@ -190,49 +190,13 @@ def validate_duplicate_dependencies # :nodoc:
 
   ##
   # Checks that the gem does not depend on itself.
-  # Checks that dependencies use requirements as we recommend.  Warnings are
-  # issued when dependencies are open-ended or overly strict for semantic
-  # versioning.
 
   def validate_dependencies # :nodoc:
     warning_messages = []
     @specification.dependencies.each do |dep|
       if dep.name == @specification.name # warn on self reference
         warning_messages << "Self referencing dependency is unnecessary and strongly discouraged."
       end
-
-      prerelease_dep = dep.requirements_list.any? do |req|
-        Gem::Requirement.new(req).prerelease?
-      end
-
-      warning_messages << "prerelease dependency on #{dep} is not recommended" if
-          prerelease_dep && !@specification.version.prerelease?
-
-      open_ended = dep.requirement.requirements.all? do |op, version|
-        !version.prerelease? && [">", ">="].include?(op)
-      end
-
-      next unless open_ended
-      op, dep_version = dep.requirement.requirements.first
-
-      segments = dep_version.segments
-
-      base = segments.first 2
-
-      recommendation = if [">", ">="].include?(op) && segments == [0]
-        "  use a bounded requirement, such as \"~> x.y\""
-      else
-        bugfix = if op == ">"
-          ", \"> #{dep_version}\""
-        elsif op == ">=" && base != segments
-          ", \">= #{dep_version}\""
-        end
-
-        "  if #{dep.name} is semantically versioned, use:\n" \
-        "    add_#{dep.type}_dependency \"#{dep.name}\", \"~> #{base.join "."}\"#{bugfix}"
-      end
-
-      warning_messages << ["open-ended dependency on #{dep} is not recommended", recommendation].join("\n") + "\n"
     end
     if warning_messages.any?
       warning_messages.each {|warning_message| warning warning_message }

test/rubygems/test_gem_specification.rb

@@ -2671,27 +2671,7 @@ def test_validate_dependencies
         @a1.validate
       end
 
-      expected = <<-EXPECTED
-#{w}:  prerelease dependency on b (>= 1.0.rc1) is not recommended
-#{w}:  prerelease dependency on c (>= 2.0.rc2, development) is not recommended
-#{w}:  open-ended dependency on i (>= 1.2) is not recommended
-  if i is semantically versioned, use:
-    add_runtime_dependency "i", "~> 1.2"
-#{w}:  open-ended dependency on j (>= 1.2.3) is not recommended
-  if j is semantically versioned, use:
-    add_runtime_dependency "j", "~> 1.2", ">= 1.2.3"
-#{w}:  open-ended dependency on k (> 1.2) is not recommended
-  if k is semantically versioned, use:
-    add_runtime_dependency "k", "~> 1.2", "> 1.2"
-#{w}:  open-ended dependency on l (> 1.2.3) is not recommended
-  if l is semantically versioned, use:
-    add_runtime_dependency "l", "~> 1.2", "> 1.2.3"
-#{w}:  open-ended dependency on o (>= 0) is not recommended
-  use a bounded requirement, such as "~> x.y"
-#{w}:  See https://guides.rubygems.org/specification-reference/ for help
-      EXPECTED
-
-      assert_equal expected, @ui.error, "warning"
+      assert_equal "", @ui.error, "warning"
     end
   end