Auto merge of #4603 - bundler:seg-allow-unlocking-when-removing-ruby, r=indirect

[Definition] Allow unlocking when removing the ruby version requirement

Closes #4595. Closes #4627.

\c @RochesterinNYC

8 files changed, 141 insertions, 8 deletions

diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 02f8ee0957..d4af6b70e7 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -85,6 +85,14 @@ module Bundler
 
       @unlock[:gems] ||= []
       @unlock[:sources] ||= []
+      @unlock[:ruby] ||= if @ruby_version && @locked_ruby_version
+        unless locked_ruby_version_object = RubyVersion.from_string(@locked_ruby_version)
+          raise LockfileError, "Failed to create a `RubyVersion` object from " \
+            "`#{@locked_ruby_version}` found in #{lockfile} -- try running `bundle update --ruby`."
+        end
+        @ruby_version.diff(locked_ruby_version_object)
+      end
+      @unlocking ||= @unlock[:ruby] || (!@locked_ruby_version ^ !@ruby_version)
 
       current_platform = Bundler.rubygems.platforms.map {|p| generic(p) }.compact.last
       add_platform(current_platform)
diff --git a/lib/bundler/ruby_version.rb b/lib/bundler/ruby_version.rb
index 5936eca830..d0e9c50af2 100644
--- a/lib/bundler/ruby_version.rb
+++ b/lib/bundler/ruby_version.rb
@@ -38,6 +38,22 @@ module Bundler
       output
     end
 
+    # @private
+    PATTERN = /
+      ruby\s
+      ([\d.]+) # ruby version
+      (?:p(\d+))? # optional patchlevel
+      (?:\s\((\S+)\s(.+)\))? # optional engine info
+    /xo
+
+    # Returns a RubyVersion from the given string.
+    # @param [String] the version string to match.
+    # @return [RubyVersion,Nil] The version if the string is a valid RubyVersion
+    #         description, and nil otherwise.
+    def self.from_string(string)
+      new($1, $2, $3, $4) if string =~ PATTERN
+    end
+
     def single_version_string
       to_s(gem_version)
     end
@@ -64,7 +80,7 @@ module Bundler
     #   2. ruby_version
     #   3. engine_version
     def diff(other)
-      raise ArgumentError, "Can only diff with a RubyVersion" unless other.is_a?(RubyVersion)
+      raise ArgumentError, "Can only diff with a RubyVersion, not a #{other.class}" unless other.is_a?(RubyVersion)
       if engine != other.engine && @input_engine
         [:engine, engine, other.engine]
       elsif versions.empty? || !matches?(versions, other.gem_version)
@@ -87,9 +103,11 @@ module Bundler
         # not defined in ruby 1.8.7
         "ruby"
       end
+      # :sob: mocking RUBY_VERSION breaks stuff on 1.8.7
+      ruby_version = ENV.fetch("BUNDLER_SPEC_RUBY_VERSION") { RUBY_VERSION }.dup
       ruby_engine_version = case ruby_engine
                             when "ruby"
-                              RUBY_VERSION.dup
+                              ruby_version
                             when "rbx"
                               Rubinius::VERSION.dup
                             when "jruby"
@@ -97,7 +115,7 @@ module Bundler
                             else
                               raise BundlerError, "RUBY_ENGINE value #{RUBY_ENGINE} is not recognized"
       end
-      @ruby_version ||= RubyVersion.new(RUBY_VERSION.dup, RUBY_PATCHLEVEL.to_s, ruby_engine, ruby_engine_version)
+      @ruby_version ||= RubyVersion.new(ruby_version, RUBY_PATCHLEVEL.to_s, ruby_engine, ruby_engine_version)
     end
 
     def to_gem_version_with_patchlevel
diff --git a/spec/bundler/ruby_version_spec.rb b/spec/bundler/ruby_version_spec.rb
index 414ec3c3c8..abcd0303d0 100644
--- a/spec/bundler/ruby_version_spec.rb
+++ b/spec/bundler/ruby_version_spec.rb
@@ -56,6 +56,40 @@ describe "Bundler::RubyVersion and its subclasses" do
         end
       end
     end
+
+    describe ".from_string" do
+      shared_examples_for "returning" do
+        it "returns the original RubyVersion" do
+          expect(described_class.from_string(subject.to_s)).to eq(subject)
+        end
+      end
+
+      include_examples "returning"
+
+      context "no patchlevel" do
+        let(:patchlevel) { nil }
+
+        include_examples "returning"
+      end
+
+      context "engine is ruby" do
+        let(:engine) { "ruby" }
+        let(:engine_version) { version }
+
+        include_examples "returning"
+      end
+
+      context "with multiple requirements" do
+        let(:engine_version) { ["> 9", "< 11"] }
+        let(:version) { ["> 8", "< 10"] }
+        let(:patchlevel) { nil }
+
+        it "returns nil" do
+          expect(described_class.from_string(subject.to_s)).to be_nil
+        end
+      end
+    end
+
     describe "#to_s" do
       it "should return info string with the ruby version, patchlevel, engine, and engine version" do
         expect(subject.to_s).to eq("ruby 2.0.0p645 (jruby 2.0.1)")
diff --git a/spec/commands/install_spec.rb b/spec/commands/install_spec.rb
index efefdbef4f..d7617cb370 100644
--- a/spec/commands/install_spec.rb
+++ b/spec/commands/install_spec.rb
@@ -391,7 +391,7 @@ describe "bundle install with gem sources" do
         L
       end
 
-      it "does not update Gemfile.lock with updated ruby versions" do
+      it "updates Gemfile.lock with updated incompatible ruby version" do
         install_gemfile <<-G, :expect_err => true
           ::RUBY_VERSION = '2.2.3'
           ::RUBY_PATCHLEVEL = 100
@@ -408,7 +408,7 @@ describe "bundle install with gem sources" do
          DEPENDENCIES
 
          RUBY VERSION
-            ruby 2.1.3p100
+            ruby 2.2.3p100
 
          BUNDLED WITH
             #{Bundler::VERSION}
diff --git a/spec/install/gemfile/ruby_spec.rb b/spec/install/gemfile/ruby_spec.rb
index d3536289eb..d250e78693 100644
--- a/spec/install/gemfile/ruby_spec.rb
+++ b/spec/install/gemfile/ruby_spec.rb
@@ -2,6 +2,10 @@
 require "spec_helper"
 
 describe "ruby requirement" do
+  def locked_ruby_version
+    Bundler::RubyVersion.from_string(Bundler::LockfileParser.new(lockfile).ruby_version)
+  end
+
   # As discovered by https://github.com/bundler/bundler/issues/4147, there is
   # no test coverage to ensure that adding a gem is possible with a ruby
   # requirement. This test verifies the fix, committed in bfbad5c5.
@@ -22,4 +26,64 @@ describe "ruby requirement" do
     expect(exitstatus).to eq(0) if exitstatus
     should_be_installed "rack-obama 1.0"
   end
+
+  it "allows removing the ruby version requirement" do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      ruby "~> #{RUBY_VERSION}"
+      gem "rack"
+    G
+
+    expect(lockfile).to include("RUBY VERSION")
+
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      gem "rack"
+    G
+
+    should_be_installed "rack 1.0.0"
+    expect(lockfile).not_to include("RUBY VERSION")
+  end
+
+  it "allows changing the ruby version requirement to something compatible" do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      ruby ">= 1.0.0"
+      gem "rack"
+    G
+
+    expect(locked_ruby_version).to eq(Bundler::RubyVersion.system)
+
+    simulate_ruby_version "5100"
+
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      ruby ">= 1.0.1"
+      gem "rack"
+    G
+
+    should_be_installed "rack 1.0.0"
+    expect(locked_ruby_version).to eq(Bundler::RubyVersion.system)
+  end
+
+  it "allows changing the ruby version requirement to something incompatible" do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      ruby ">= 1.0.0"
+      gem "rack"
+    G
+
+    expect(locked_ruby_version).to eq(Bundler::RubyVersion.system)
+
+    simulate_ruby_version "5100"
+
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      ruby ">= 5000.0"
+      gem "rack"
+    G
+
+    should_be_installed "rack 1.0.0"
+    expect(locked_ruby_version.versions).to eq(["5100"])
+  end
 end
diff --git a/spec/other/platform_spec.rb b/spec/other/platform_spec.rb
index 8d546fca57..a219853e2f 100644
--- a/spec/other/platform_spec.rb
+++ b/spec/other/platform_spec.rb
@@ -376,7 +376,7 @@ G
 
       bundle :check
       expect(exitstatus).to eq(0) if exitstatus
-      expect(out).to eq("The Gemfile's dependencies are satisfied")
+      expect(out).to eq("Resolving dependencies...\nThe Gemfile's dependencies are satisfied")
     end
 
     it "checks fine with any engine" do
@@ -395,7 +395,7 @@ G
 
         bundle :check
         expect(exitstatus).to eq(0) if exitstatus
-        expect(out).to eq("The Gemfile's dependencies are satisfied")
+        expect(out).to eq("Resolving dependencies...\nThe Gemfile's dependencies are satisfied")
       end
     end
 
diff --git a/spec/runtime/setup_spec.rb b/spec/runtime/setup_spec.rb
index f9528199cc..14377ed17e 100644
--- a/spec/runtime/setup_spec.rb
+++ b/spec/runtime/setup_spec.rb
@@ -1032,7 +1032,7 @@ describe "Bundler.setup" do
       L
 
       if ruby_version
-        lock += "\n        RUBY VERSION\n           #{ruby_version}\n"
+        lock += "\n        RUBY VERSION\n           ruby #{ruby_version}\n"
       end
 
       lock += <<-L
diff --git a/spec/support/helpers.rb b/spec/support/helpers.rb
index 75ee592826..ff41dfbfa4 100644
--- a/spec/support/helpers.rb
+++ b/spec/support/helpers.rb
@@ -347,6 +347,15 @@ module Spec
       ENV["BUNDLER_SPEC_PLATFORM"] = old if block_given?
     end
 
+    def simulate_ruby_version(version)
+      return if version == RUBY_VERSION
+      old = ENV["BUNDLER_SPEC_RUBY_VERSION"]
+      ENV["BUNDLER_SPEC_RUBY_VERSION"] = version
+      yield if block_given?
+    ensure
+      ENV["BUNDLER_SPEC_RUBY_VERSION"] = old if block_given?
+    end
+
     def simulate_ruby_engine(engine, version = "1.6.0")
       return if engine == local_ruby_engine