Fix GemIndex not correctly finding all specifications.

The wrong API call was being used to search for all specifications.
RubyGems 2.x expects Gem::Specification.each to be called to iterate
over all specs. find_all_* does not accept ''.

Fixes #1058

lib/yard/cli/diff.rb

@@ -131,7 +131,7 @@ def load_gem_data(gemfile)
         # Next check installed RubyGems
         gemfile_without_ext = gemfile.sub(/\.gem$/, '')
         log.info "Searching for installed gem #{gemfile_without_ext}"
-        YARD::GemIndex.find_all_by_name('').find do |spec|
+        YARD::GemIndex.each.find do |spec|
           next unless spec.full_name == gemfile_without_ext
           yardoc = Registry.yardoc_file_for_gem(spec.name, "= #{spec.version}")
           if yardoc

lib/yard/cli/gems.rb

@@ -76,7 +76,7 @@ def optparse(*args)
         if !args.empty? && @gems.empty?
           log.error "No specified gems could be found for command"
         elsif @gems.empty?
-          @gems += YARD::GemIndex.find_all_by_name('') if @gems.empty?
+          @gems += YARD::GemIndex.all if @gems.empty?
         end
       end
     end

lib/yard/cli/server.rb

@@ -127,7 +127,7 @@ def create_library_version_if_yardopts_exist(library, dir)
 
       def add_gems
         require 'rubygems'
-        YARD::GemIndex.find_all_by_name('').each do |spec|
+        YARD::GemIndex.each do |spec|
           libraries[spec.name] ||= []
           libraries[spec.name] |= [YARD::Server::LibraryVersion.new(spec.name, spec.version.to_s, nil, :gem)]
         end

lib/yard/cli/yri.rb

@@ -161,7 +161,7 @@ def load_cache
       def add_gem_paths
         require 'rubygems'
         gem_paths = []
-        YARD::GemIndex.find_all_by_name('').each do |spec|
+        YARD::GemIndex.each do |spec|
           yfile = Registry.yardoc_file_for_gem(spec.name)
           next if yfile.nil?
 

lib/yard/config.rb

@@ -170,7 +170,7 @@ def self.load_gem_plugins
       return true unless options[:load_plugins]
       require 'rubygems'
       result = true
-      YARD::GemIndex.find_all_by_name('').each do |gem|
+      YARD::GemIndex.each do |gem|
         begin
           next true unless gem.name =~ YARD_PLUGIN_PREFIX
           load_plugin(gem.name)

lib/yard/gem_index.rb

@@ -13,5 +13,17 @@ def find_all_by_name(*args)
         Gem.source_index.find_name(*args)
       end
     end
+
+    def each(&block)
+      if defined?(Gem::Specification) && Gem::Specification.respond_to?(:each)
+        Gem::Specification.each(&block)
+      else
+        Gem.source_index.find_name('').each(&block)
+      end
+    end
+
+    def all
+      each.to_a
+    end
   end
 end

spec/cli/diff_spec.rb

@@ -199,7 +199,7 @@ def baz; BAR end
       expect(File).to receive(:directory?).with('gem2-1.0.0').and_return(false)
       spec1   = double(:spec)
       spec2   = double(:spec)
-      expect(YARD::GemIndex).to receive(:find_all_by_name).at_least(1).times.and_return([spec1, spec2])
+      allow(YARD::GemIndex).to receive(:each) {|&b| [spec1, spec2].each(&b) }
       allow(spec1).to receive(:full_name).and_return('gem1-1.0.0')
       allow(spec1).to receive(:name).and_return('gem1')
       allow(spec1).to receive(:version).and_return('1.0.0')

spec/cli/gems_spec.rb

@@ -32,7 +32,7 @@ def build_specs(*specs)
   describe "#run" do
     it "builds all gem indexes if no gem is specified" do
       build_specs(@gem1, @gem2)
-      expect(YARD::GemIndex).to receive(:find_all_by_name).with('').and_return([@gem1, @gem2])
+      expect(YARD::GemIndex).to receive(:each) {|&b| [@gem1, @gem2].each(&b) }
       CLI::Gems.run
     end
 
@@ -74,7 +74,7 @@ def build_specs(*specs)
     it "accepts --rebuild" do
       @rebuild = true
       build_specs(@gem1)
-      expect(YARD::GemIndex).to receive(:find_all_by_name).with('').and_return([@gem1])
+      expect(YARD::GemIndex).to receive(:each) {|&b| [@gem1].each(&b) }
       CLI::Gems.run('--rebuild')
     end
   end

spec/cli/server_spec.rb

@@ -251,8 +251,9 @@ def mock_file(filename, content = nil)
       gem2 = double(:gem2, :name => 'gem2', :version => '1.0.0', :full_gem_path => '/path/to/bar')
       specs = {'gem1' => gem1, 'gem2' => gem2}
       allow(YARD::GemIndex).to receive(:find_all_by_name) do |k, _ver|
-        k == '' ? specs.values : specs.grep(k).map {|name| specs[name] }
+        specs.grep(k).map {|name| specs[name] }
       end
+      allow(YARD::GemIndex).to receive(:each) {|&b| specs.values.each(&b) }
       run '-g'
       run '--gems'
     end

spec/config_spec.rb

@@ -147,7 +147,7 @@
         expect(v).to receive(:name).at_least(1).times.and_return(k)
       end
 
-      expect(YARD::GemIndex).to receive(:find_all_by_name).with('').and_return(plugins.values)
+      expect(YARD::GemIndex).to receive(:each) {|&b| plugins.values.each(&b) }
       expect(YARD::Config).to receive(:load_plugin).with('yard_plugin').and_return(false)
       expect(YARD::Config).to receive(:load_plugin).with('yard-plugin').and_return(true)
       expect(YARD::Config.load_plugins).to be true
@@ -162,7 +162,7 @@
         expect(v).to receive(:name).at_least(1).times.and_return(k)
       end
 
-      expect(YARD::GemIndex).to receive(:find_all_by_name).with('').and_return(plugins.values)
+      expect(YARD::GemIndex).to receive(:each) {|&b| plugins.values.each(&b) }
       expect(YARD::Config).to receive(:load_plugin).with('yard-plugin').and_raise(Gem::LoadError)
       expect(log).to receive(:error).with(/Error loading plugin 'yard-plugin'/)
       expect(YARD::Config.load_plugins).to be false