[rubygems/rubygems] Let fetch understand gem:version syntax

Fix version error message

Add tests to fetch error messages

Fix default version since is not necessary

https://github.com/rubygems/rubygems/commit/070620ebe4

lib/rubygems/commands/fetch_command.rb

@@ -18,6 +18,10 @@ class Gem::Commands::FetchCommand < Gem::Command
     add_version_option
     add_platform_option
     add_prerelease_option
+
+    add_option '--[no-]suggestions', 'Suggest alternates when gems are not found' do |value, options|
+      options[:suggest_alternate] = true
+    end
   end
 
   def arguments # :nodoc:
@@ -42,15 +46,27 @@ then repackaging it.
     "#{program_name} GEMNAME [GEMNAME ...]"
   end
 
+  def check_version # :nodoc:
+    if options[:version] and options[:version] != Gem::Requirement.default and
+         get_all_gem_names.size > 1
+      alert_error "Can't use --version with multiple gems. You can specify multiple gems with" \
+                  " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+      terminate_interaction 1
+    end
+  end
+
   def execute
-    version = options[:version] || Gem::Requirement.default
+    check_version
+    version = options[:version]
 
     platform  = Gem.platforms.last
-    gem_names = get_all_gem_names
+    gem_names = get_all_gem_names_and_versions
 
-    gem_names.each do |gem_name|
+    gem_names.each do |gem_name, gem_version|
-      dep = Gem::Dependency.new gem_name, version
+      gem_version ||= version
+      dep = Gem::Dependency.new gem_name, gem_version
       dep.prerelease = options[:prerelease]
+      suppress_suggestions = options[:suggest_alternate]
 
       specs_and_sources, errors =
         Gem::SpecFetcher.fetcher.spec_for_dependency dep
@@ -63,12 +79,10 @@ then repackaging it.
       spec, source = specs_and_sources.max_by {|s,| s }
 
       if spec.nil?
-        show_lookup_failure gem_name, version, errors, options[:domain]
+        show_lookup_failure gem_name, gem_version, errors, suppress_suggestions, options[:domain]
         next
       end
-
       source.download spec
-
       say "Downloaded #{spec.full_name}"
     end
   end

test/rubygems/test_gem_commands_fetch_command.rb

@@ -157,4 +157,101 @@ class TestGemCommandsFetchCommand < Gem::TestCase
     assert_path_exist(File.join(@tempdir, a1.file_name),
                        "#{a1.full_name} not fetched")
   end
+
+  def test_execute_version_specified_by_colon
+    specs = spec_fetcher do |fetcher|
+      fetcher.gem 'a', 1
+    end
+
+    @cmd.options[:args] = %w[a:1]
+
+    use_ui @ui do
+      Dir.chdir @tempdir do
+        @cmd.execute
+      end
+    end
+
+    a1 = specs['a-1']
+
+    assert_path_exist(File.join(@tempdir, a1.file_name),
+                       "#{a1.full_name} not fetched")
+  end
+
+  def test_execute_two_version
+    @cmd.options[:args] = %w[a b]
+    @cmd.options[:version] = Gem::Requirement.new '1'
+
+    use_ui @ui do
+      assert_raise Gem::MockGemUi::TermError, @ui.error do
+        @cmd.execute
+      end
+    end
+
+    msg = "ERROR:  Can't use --version with multiple gems. You can specify multiple gems with" \
+      " version requirements using `gem fetch 'my_gem:1.0.0' 'my_other_gem:~>2.0.0'`"
+
+    assert_empty @ui.output
+    assert_equal msg, @ui.error.chomp
+  end
+
+  def test_execute_two_version_specified_by_colon
+    specs = spec_fetcher do |fetcher|
+      fetcher.gem 'a', 1
+      fetcher.gem 'b', 1
+    end
+
+    @cmd.options[:args] = %w[a:1 b:1]
+
+    use_ui @ui do
+      Dir.chdir @tempdir do
+        @cmd.execute
+      end
+    end
+
+    a1 = specs['a-1']
+    b1 = specs['b-1']
+
+    assert_path_exist(File.join(@tempdir, a1.file_name),
+                       "#{a1.full_name} not fetched")
+    assert_path_exist(File.join(@tempdir, b1.file_name),
+                       "#{b1.full_name} not fetched")
+  end
+
+  def test_execute_version_nonexistent
+    spec_fetcher do |fetcher|
+      fetcher.spec 'foo', 1
+    end
+
+    @cmd.options[:args] = %w[foo:2]
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    expected = <<-EXPECTED
+ERROR:  Could not find a valid gem 'foo' (2) in any repository
+ERROR:  Possible alternatives: foo
+    EXPECTED
+
+    assert_equal expected, @ui.error
+  end
+
+  def test_execute_nonexistent_hint_disabled
+    spec_fetcher do |fetcher|
+      fetcher.spec 'foo', 1
+    end
+
+    @cmd.options[:args] = %w[foo:2]
+    @cmd.options[:suggest_alternate] = true
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    expected = <<-EXPECTED
+ERROR:  Could not find a valid gem 'foo' (2) in any repository
+    EXPECTED
+
+    assert_equal expected, @ui.error
+  end
 end