[rubygems/rubygems] Extract generate_index command to rubygems-generate_index gem

So generate_index can be implemented with dependencies, such as the compact index

Took this approach from feedback in https://github.com/rubygems/rubygems/pull/6853

Running `gem generate_index` by default will use an installed rubygems-generate_index, or install and then use the command from the gem

Apply suggestions from code review

https://github.com/rubygems/rubygems/commit/fc1cb9bc9e

Co-authored-by: Hiroshi SHIBATA <hsbt@ruby-lang.org>

3 files changed, 17 insertions, 12 deletions

diff --git a/spec/bundler/commands/install_spec.rb b/spec/bundler/commands/install_spec.rb
index 5f5c9bb286..aa7c54ce4b 100644
--- a/spec/bundler/commands/install_spec.rb
+++ b/spec/bundler/commands/install_spec.rb
@@ -556,7 +556,7 @@ RSpec.describe "bundle install with gem sources" do
     end
 
     it "fails gracefully when downloading an invalid specification from the full index" do
-      build_repo2 do
+      build_repo2(build_compact_index: false) do
         build_gem "ajp-rails", "0.0.0", gemspec: false, skip_validation: true do |s|
           bad_deps = [["ruby-ajp", ">= 0.2.0"], ["rails", ">= 0.14"]]
           s.
diff --git a/spec/bundler/install/gems/compact_index_spec.rb b/spec/bundler/install/gems/compact_index_spec.rb
index 51d7af9ee2..f3b8bb708d 100644
--- a/spec/bundler/install/gems/compact_index_spec.rb
+++ b/spec/bundler/install/gems/compact_index_spec.rb
@@ -44,7 +44,7 @@ RSpec.describe "compact index api" do
   end
 
   it "should handle case sensitivity conflicts" do
-    build_repo4 do
+    build_repo4(build_compact_index: false) do
       build_gem "rack", "1.0" do |s|
         s.add_runtime_dependency("Rack", "0.1")
       end
diff --git a/spec/bundler/support/builders.rb b/spec/bundler/support/builders.rb
index 76e05b5203..d36c5d4717 100644
--- a/spec/bundler/support/builders.rb
+++ b/spec/bundler/support/builders.rb
@@ -191,25 +191,25 @@ module Spec
       end
     end
 
-    def build_repo2(&blk)
+    def build_repo2(**kwargs, &blk)
       FileUtils.rm_rf gem_repo2
       FileUtils.cp_r gem_repo1, gem_repo2
-      update_repo2(&blk) if block_given?
+      update_repo2(**kwargs, &blk) if block_given?
     end
 
     # A repo that has no pre-installed gems included. (The caller completely
     # determines the contents with the block.)
-    def build_repo4(&blk)
+    def build_repo4(**kwargs, &blk)
       FileUtils.rm_rf gem_repo4
-      build_repo(gem_repo4, &blk)
+      build_repo(gem_repo4, **kwargs, &blk)
     end
 
     def update_repo4(&blk)
       update_repo(gem_repo4, &blk)
     end
 
-    def update_repo2(&blk)
-      update_repo(gem_repo2, &blk)
+    def update_repo2(**kwargs, &blk)
+      update_repo(gem_repo2, **kwargs, &blk)
     end
 
     def build_security_repo
@@ -227,12 +227,12 @@ module Spec
       end
     end
 
-    def build_repo(path, &blk)
+    def build_repo(path, **kwargs, &blk)
       return if File.directory?(path)
 
       FileUtils.mkdir_p("#{path}/gems")
 
-      update_repo(path, &blk)
+      update_repo(path,**kwargs, &blk)
     end
 
     def check_test_gems!
@@ -249,7 +249,7 @@ module Spec
       end
     end
 
-    def update_repo(path)
+    def update_repo(path, build_compact_index: true)
       if path == gem_repo1 && caller.first.split(" ").last == "`build_repo`"
         raise "Updating gem_repo1 is unsupported -- use gem_repo2 instead"
       end
@@ -258,7 +258,12 @@ module Spec
       @_build_repo = File.basename(path)
       yield
       with_gem_path_as Path.base_system_gem_path do
-        gem_command :generate_index, dir: path
+        Dir[Spec::Path.base_system_gem_path.join("gems/rubygems-generate_index*/lib")].first ||
+          raise("Could not find rubygems-generate_index lib directory in #{Spec::Path.base_system_gem_path}")
+
+        command = "generate_index"
+        command += " --no-compact" if !build_compact_index && gem_command(command + " --help").include?("--[no-]compact")
+        gem_command command, dir: path
       end
     ensure
       @_build_path = nil