Merge bundler to standard libraries.

  rubygems 2.7.x depends bundler-1.15.x. This is preparation for
  rubygems and bundler migration.

  * lib/bundler.rb, lib/bundler/*: files of bundler-1.15.4
  * spec/bundler/*: rspec examples of bundler-1.15.4. I applied patches.
    * https://github.com/bundler/bundler/pull/6007
    * Exclude not working examples on ruby repository.
    * Fake ruby interpriter instead of installed ruby.
  * Makefile.in: Added test task named `test-bundler`. This task is only
    working macOS/linux yet. I'm going to support Windows environment later.
  * tool/sync_default_gems.rb: Added sync task for bundler.

  [Feature #12733][ruby-core:77172]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59779 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

35 files changed, 945 insertions, 0 deletions

diff --git a/spec/bundler/support/artifice/compact_index.rb b/spec/bundler/support/artifice/compact_index.rb
new file mode 100644
index 0000000000..9111ed8211
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index.rb
@@ -0,0 +1,121 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+$LOAD_PATH.unshift Dir[base_system_gems.join("gems/compact_index*/lib")].first.to_s
+require "compact_index"
+
+class CompactIndexAPI < Endpoint
+  helpers do
+    def load_spec(name, version, platform, gem_repo)
+      full_name = "#{name}-#{version}"
+      full_name += "-#{platform}" if platform != "ruby"
+      Marshal.load(Gem.inflate(File.open(gem_repo.join("quick/Marshal.4.8/#{full_name}.gemspec.rz")).read))
+    end
+
+    def etag_response
+      response_body = yield
+      checksum = Digest::MD5.hexdigest(response_body)
+      return if not_modified?(checksum)
+      headers "ETag" => quote(checksum)
+      headers "Surrogate-Control" => "max-age=2592000, stale-while-revalidate=60"
+      content_type "text/plain"
+      requested_range_for(response_body)
+    rescue => e
+      puts e
+      puts e.backtrace
+      raise
+    end
+
+    def not_modified?(checksum)
+      etags = parse_etags(request.env["HTTP_IF_NONE_MATCH"])
+
+      return unless etags.include?(checksum)
+      headers "ETag" => quote(checksum)
+      status 304
+      body ""
+    end
+
+    def requested_range_for(response_body)
+      ranges = Rack::Utils.byte_ranges(env, response_body.bytesize)
+
+      if ranges
+        status 206
+        body ranges.map! {|range| slice_body(response_body, range) }.join
+      else
+        status 200
+        body response_body
+      end
+    end
+
+    def quote(string)
+      %("#{string}")
+    end
+
+    def parse_etags(value)
+      value ? value.split(/, ?/).select {|s| s.sub!(/"(.*)"/, '\1') } : []
+    end
+
+    def slice_body(body, range)
+      if body.respond_to?(:byteslice)
+        body.byteslice(range)
+      else # pre-1.9.3
+        body.unpack("@#{range.first}a#{range.end + 1}").first
+      end
+    end
+
+    def gems(gem_repo = GEM_REPO)
+      @gems ||= {}
+      @gems[gem_repo] ||= begin
+        specs = Bundler::Deprecate.skip_during do
+          %w(specs.4.8 prerelease_specs.4.8).map do |filename|
+            Marshal.load(File.open(gem_repo.join(filename)).read).map do |name, version, platform|
+              load_spec(name, version, platform, gem_repo)
+            end
+          end.flatten
+        end
+
+        specs.group_by(&:name).map do |name, versions|
+          gem_versions = versions.map do |spec|
+            deps = spec.dependencies.select {|d| d.type == :runtime }.map do |d|
+              reqs = d.requirement.requirements.map {|r| r.join(" ") }.join(", ")
+              CompactIndex::Dependency.new(d.name, reqs)
+            end
+            checksum = begin
+                         Digest::SHA256.file("#{GEM_REPO}/gems/#{spec.original_name}.gem").base64digest
+                       rescue
+                         nil
+                       end
+            CompactIndex::GemVersion.new(spec.version.version, spec.platform.to_s, checksum, nil,
+              deps, spec.required_ruby_version, spec.required_rubygems_version)
+          end
+          CompactIndex::Gem.new(name, gem_versions)
+        end
+      end
+    end
+  end
+
+  get "/names" do
+    etag_response do
+      CompactIndex.names(gems.map(&:name))
+    end
+  end
+
+  get "/versions" do
+    etag_response do
+      file = tmp("versions.list")
+      file.delete if file.file?
+      file = CompactIndex::VersionsFile.new(file.to_s)
+      file.create(gems)
+      file.contents
+    end
+  end
+
+  get "/info/:name" do
+    etag_response do
+      gem = gems.find {|g| g.name == params[:name] }
+      CompactIndex.info(gem ? gem.versions : [])
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexAPI)
diff --git a/spec/bundler/support/artifice/compact_index_api_missing.rb b/spec/bundler/support/artifice/compact_index_api_missing.rb
new file mode 100644
index 0000000000..6d15b54b85
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_api_missing.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexApiMissing < CompactIndexAPI
+  get "/fetch/actual/gem/:id" do
+    $stderr.puts params[:id]
+    if params[:id] == "rack-1.0.gemspec.rz"
+      halt 404
+    else
+      File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexApiMissing)
diff --git a/spec/bundler/support/artifice/compact_index_basic_authentication.rb b/spec/bundler/support/artifice/compact_index_basic_authentication.rb
new file mode 100644
index 0000000000..bffb5b9e2b
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_basic_authentication.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexBasicAuthentication < CompactIndexAPI
+  before do
+    unless env["HTTP_AUTHORIZATION"]
+      halt 401, "Authentication info not supplied"
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexBasicAuthentication)
diff --git a/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb b/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb
new file mode 100644
index 0000000000..4ac328736c
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexChecksumMismatch < CompactIndexAPI
+  get "/versions" do
+    headers "ETag" => quote("123")
+    headers "Surrogate-Control" => "max-age=2592000, stale-while-revalidate=60"
+    content_type "text/plain"
+    body ""
+  end
+end
+
+Artifice.activate_with(CompactIndexChecksumMismatch)
diff --git a/spec/bundler/support/artifice/compact_index_concurrent_download.rb b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
new file mode 100644
index 0000000000..b788a852cf
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexConcurrentDownload < CompactIndexAPI
+  get "/versions" do
+    versions = File.join(Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
+      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "versions")
+
+    # Verify the original (empty) content hasn't been deleted, e.g. on a retry
+    File.read(versions) == "" || raise("Original file should be present and empty")
+
+    # Verify this is only requested once for a partial download
+    env["HTTP_RANGE"] || raise("Missing Range header for expected partial download")
+
+    # Overwrite the file in parallel, which should be then overwritten
+    # after a successful download to prevent corruption
+    File.open(versions, "w") {|f| f.puts "another process" }
+
+    etag_response do
+      file = tmp("versions.list")
+      file.delete if file.file?
+      file = CompactIndex::VersionsFile.new(file.to_s)
+      file.create(gems)
+      file.contents
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexConcurrentDownload)
diff --git a/spec/bundler/support/artifice/compact_index_creds_diff_host.rb b/spec/bundler/support/artifice/compact_index_creds_diff_host.rb
new file mode 100644
index 0000000000..0c417f0580
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_creds_diff_host.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexCredsDiffHost < CompactIndexAPI
+  helpers do
+    def auth
+      @auth ||= Rack::Auth::Basic::Request.new(request.env)
+    end
+
+    def authorized?
+      auth.provided? && auth.basic? && auth.credentials && auth.credentials == %w(user pass)
+    end
+
+    def protected!
+      return if authorized?
+      response["WWW-Authenticate"] = %(Basic realm="Testing HTTP Auth")
+      throw(:halt, [401, "Not authorized\n"])
+    end
+  end
+
+  before do
+    protected! unless request.path_info.include?("/no/creds/")
+  end
+
+  get "/gems/:id" do
+    redirect "http://diffhost.com/no/creds/#{params[:id]}"
+  end
+
+  get "/no/creds/:id" do
+    if request.host.include?("diffhost") && !auth.provided?
+      File.read("#{gem_repo1}/gems/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexCredsDiffHost)
diff --git a/spec/bundler/support/artifice/compact_index_extra.rb b/spec/bundler/support/artifice/compact_index_extra.rb
new file mode 100644
index 0000000000..8a87fc4343
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_extra.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexExtra < CompactIndexAPI
+  get "/extra/versions" do
+    halt 404
+  end
+
+  get "/extra/api/v1/dependencies" do
+    halt 404
+  end
+
+  get "/extra/specs.4.8.gz" do
+    File.read("#{gem_repo2}/specs.4.8.gz")
+  end
+
+  get "/extra/prerelease_specs.4.8.gz" do
+    File.read("#{gem_repo2}/prerelease_specs.4.8.gz")
+  end
+
+  get "/extra/quick/Marshal.4.8/:id" do
+    redirect "/extra/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/extra/fetch/actual/gem/:id" do
+    File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+  end
+
+  get "/extra/gems/:id" do
+    File.read("#{gem_repo2}/gems/#{params[:id]}")
+  end
+end
+
+Artifice.activate_with(CompactIndexExtra)
diff --git a/spec/bundler/support/artifice/compact_index_extra_api.rb b/spec/bundler/support/artifice/compact_index_extra_api.rb
new file mode 100644
index 0000000000..844a9ca9f2
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_extra_api.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexExtraApi < CompactIndexAPI
+  get "/extra/names" do
+    etag_response do
+      CompactIndex.names(gems(gem_repo4).map(&:name))
+    end
+  end
+
+  get "/extra/versions" do
+    etag_response do
+      file = tmp("versions.list")
+      file.delete if file.file?
+      file = CompactIndex::VersionsFile.new(file.to_s)
+      file.create(gems(gem_repo4))
+      file.contents
+    end
+  end
+
+  get "/extra/info/:name" do
+    etag_response do
+      gem = gems(gem_repo4).find {|g| g.name == params[:name] }
+      CompactIndex.info(gem ? gem.versions : [])
+    end
+  end
+
+  get "/extra/specs.4.8.gz" do
+    File.read("#{gem_repo4}/specs.4.8.gz")
+  end
+
+  get "/extra/prerelease_specs.4.8.gz" do
+    File.read("#{gem_repo4}/prerelease_specs.4.8.gz")
+  end
+
+  get "/extra/quick/Marshal.4.8/:id" do
+    redirect "/extra/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/extra/fetch/actual/gem/:id" do
+    File.read("#{gem_repo4}/quick/Marshal.4.8/#{params[:id]}")
+  end
+
+  get "/extra/gems/:id" do
+    File.read("#{gem_repo4}/gems/#{params[:id]}")
+  end
+end
+
+Artifice.activate_with(CompactIndexExtraApi)
diff --git a/spec/bundler/support/artifice/compact_index_extra_missing.rb b/spec/bundler/support/artifice/compact_index_extra_missing.rb
new file mode 100644
index 0000000000..2af5ce9c27
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_extra_missing.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index_extra", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexExtraMissing < CompactIndexExtra
+  get "/extra/fetch/actual/gem/:id" do
+    if params[:id] == "missing-1.0.gemspec.rz"
+      halt 404
+    else
+      File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexExtraMissing)
diff --git a/spec/bundler/support/artifice/compact_index_forbidden.rb b/spec/bundler/support/artifice/compact_index_forbidden.rb
new file mode 100644
index 0000000000..b25eea94e7
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_forbidden.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexForbidden < CompactIndexAPI
+  get "/versions" do
+    halt 403
+  end
+end
+
+Artifice.activate_with(CompactIndexForbidden)
diff --git a/spec/bundler/support/artifice/compact_index_host_redirect.rb b/spec/bundler/support/artifice/compact_index_host_redirect.rb
new file mode 100644
index 0000000000..6c1ab2def6
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_host_redirect.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexHostRedirect < CompactIndexAPI
+  get "/fetch/actual/gem/:id", :host_name => "localgemserver.test" do
+    redirect "http://bundler.localgemserver.test#{request.path_info}"
+  end
+
+  get "/versions" do
+    status 404
+  end
+
+  get "/api/v1/dependencies" do
+    status 404
+  end
+end
+
+Artifice.activate_with(CompactIndexHostRedirect)
diff --git a/spec/bundler/support/artifice/compact_index_partial_update.rb b/spec/bundler/support/artifice/compact_index_partial_update.rb
new file mode 100644
index 0000000000..bf6feab877
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_partial_update.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexPartialUpdate < CompactIndexAPI
+  # Stub the server to never return 304s. This simulates the behaviour of
+  # Fastly / Rubygems ignoring ETag headers.
+  def not_modified?(_checksum)
+    false
+  end
+
+  get "/versions" do
+    cached_versions_path = File.join(
+      Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
+      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "versions"
+    )
+
+    # Verify a cached copy of the versions file exists
+    unless File.read(cached_versions_path).start_with?("created_at: ")
+      raise("Cached versions file should be present and have content")
+    end
+
+    # Verify that a partial request is made, starting from the index of the
+    # final byte of the cached file.
+    unless env["HTTP_RANGE"] == "bytes=#{File.read(cached_versions_path).bytesize - 1}-"
+      raise("Range header should be present, and start from the index of the final byte of the cache.")
+    end
+
+    etag_response do
+      # Return the exact contents of the cache.
+      File.read(cached_versions_path)
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexPartialUpdate)
diff --git a/spec/bundler/support/artifice/compact_index_redirects.rb b/spec/bundler/support/artifice/compact_index_redirects.rb
new file mode 100644
index 0000000000..ff1d3e43bc
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_redirects.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexRedirect < CompactIndexAPI
+  get "/fetch/actual/gem/:id" do
+    redirect "/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/versions" do
+    status 404
+  end
+
+  get "/api/v1/dependencies" do
+    status 404
+  end
+end
+
+Artifice.activate_with(CompactIndexRedirect)
diff --git a/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb b/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb
new file mode 100644
index 0000000000..49a072d2b9
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexStrictBasicAuthentication < CompactIndexAPI
+  before do
+    unless env["HTTP_AUTHORIZATION"]
+      halt 401, "Authentication info not supplied"
+    end
+
+    # Only accepts password == "password"
+    unless env["HTTP_AUTHORIZATION"] == "Basic dXNlcjpwYXNz"
+      halt 403, "Authentication failed"
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexStrictBasicAuthentication)
diff --git a/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb b/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb
new file mode 100644
index 0000000000..25935f5e5d
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexWrongDependencies < CompactIndexAPI
+  get "/info/:name" do
+    etag_response do
+      gem = gems.find {|g| g.name == params[:name] }
+      gem.versions.each {|gv| gv.dependencies.clear } if gem
+      CompactIndex.info(gem ? gem.versions : [])
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexWrongDependencies)
diff --git a/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb b/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb
new file mode 100644
index 0000000000..3a12a59ae7
--- /dev/null
+++ b/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+require File.expand_path("../compact_index", __FILE__)
+
+Artifice.deactivate
+
+class CompactIndexWrongGemChecksum < CompactIndexAPI
+  get "/info/:name" do
+    etag_response do
+      name = params[:name]
+      gem = gems.find {|g| g.name == name }
+      checksum = ENV.fetch("BUNDLER_SPEC_#{name.upcase}_CHECKSUM") { "ab" * 22 }
+      versions = gem ? gem.versions : []
+      versions.each {|v| v.checksum = checksum }
+      CompactIndex.info(versions)
+    end
+  end
+end
+
+Artifice.activate_with(CompactIndexWrongGemChecksum)
diff --git a/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb b/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb
new file mode 100644
index 0000000000..f1f8dc5700
--- /dev/null
+++ b/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint_marshal_fail", __FILE__)
+
+Artifice.deactivate
+
+class EndpointMarshalFailBasicAuthentication < EndpointMarshalFail
+  before do
+    unless env["HTTP_AUTHORIZATION"]
+      halt 401, "Authentication info not supplied"
+    end
+  end
+end
+
+Artifice.activate_with(EndpointMarshalFailBasicAuthentication)
diff --git a/spec/bundler/support/artifice/endpoint.rb b/spec/bundler/support/artifice/endpoint.rb
new file mode 100644
index 0000000000..771d431f22
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+require File.expand_path("../../path.rb", __FILE__)
+require Spec::Path.root.join("lib/bundler/deprecate")
+include Spec::Path
+
+$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gems.join("gems/{artifice,rack,tilt,sinatra}-*/lib")].map(&:to_s))
+require "artifice"
+require "sinatra/base"
+
+class Endpoint < Sinatra::Base
+  GEM_REPO = Pathname.new(ENV["BUNDLER_SPEC_GEM_REPO"] || Spec::Path.gem_repo1)
+  set :raise_errors, true
+  set :show_exceptions, false
+
+  helpers do
+    def dependencies_for(gem_names, gem_repo = GEM_REPO)
+      return [] if gem_names.nil? || gem_names.empty?
+
+      require "rubygems"
+      require "bundler"
+      Bundler::Deprecate.skip_during do
+        all_specs = %w(specs.4.8 prerelease_specs.4.8).map do |filename|
+          Marshal.load(File.open(gem_repo.join(filename)).read)
+        end.inject(:+)
+
+        all_specs.map do |name, version, platform|
+          spec = load_spec(name, version, platform, gem_repo)
+          next unless gem_names.include?(spec.name)
+          {
+            :name         => spec.name,
+            :number       => spec.version.version,
+            :platform     => spec.platform.to_s,
+            :dependencies => spec.dependencies.select {|dep| dep.type == :runtime }.map do |dep|
+              [dep.name, dep.requirement.requirements.map {|a| a.join(" ") }.join(", ")]
+            end
+          }
+        end.compact
+      end
+    end
+
+    def load_spec(name, version, platform, gem_repo)
+      full_name = "#{name}-#{version}"
+      full_name += "-#{platform}" if platform != "ruby"
+      Marshal.load(Gem.inflate(File.open(gem_repo.join("quick/Marshal.4.8/#{full_name}.gemspec.rz")).read))
+    end
+  end
+
+  get "/quick/Marshal.4.8/:id" do
+    redirect "/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/fetch/actual/gem/:id" do
+    File.read("#{GEM_REPO}/quick/Marshal.4.8/#{params[:id]}")
+  end
+
+  get "/gems/:id" do
+    File.read("#{GEM_REPO}/gems/#{params[:id]}")
+  end
+
+  get "/api/v1/dependencies" do
+    Marshal.dump(dependencies_for(params[:gems]))
+  end
+
+  get "/specs.4.8.gz" do
+    File.read("#{GEM_REPO}/specs.4.8.gz")
+  end
+
+  get "/prerelease_specs.4.8.gz" do
+    File.read("#{GEM_REPO}/prerelease_specs.4.8.gz")
+  end
+end
+
+Artifice.activate_with(Endpoint)
diff --git a/spec/bundler/support/artifice/endpoint_500.rb b/spec/bundler/support/artifice/endpoint_500.rb
new file mode 100644
index 0000000000..993630b79e
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_500.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require File.expand_path("../../path.rb", __FILE__)
+include Spec::Path
+
+$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gems.join("gems/{artifice,rack,tilt,sinatra}-*/lib")].map(&:to_s))
+
+require "artifice"
+require "sinatra/base"
+
+Artifice.deactivate
+
+class Endpoint500 < Sinatra::Base
+  before do
+    halt 500
+  end
+end
+
+Artifice.activate_with(Endpoint500)
diff --git a/spec/bundler/support/artifice/endpoint_api_forbidden.rb b/spec/bundler/support/artifice/endpoint_api_forbidden.rb
new file mode 100644
index 0000000000..21ad9117ed
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_api_forbidden.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointApiForbidden < Endpoint
+  get "/api/v1/dependencies" do
+    halt 403
+  end
+end
+
+Artifice.activate_with(EndpointApiForbidden)
diff --git a/spec/bundler/support/artifice/endpoint_api_missing.rb b/spec/bundler/support/artifice/endpoint_api_missing.rb
new file mode 100644
index 0000000000..6f5b5f1323
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_api_missing.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointApiMissing < Endpoint
+  get "/fetch/actual/gem/:id" do
+    $stderr.puts params[:id]
+    if params[:id] == "rack-1.0.gemspec.rz"
+      halt 404
+    else
+      File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(EndpointApiMissing)
diff --git a/spec/bundler/support/artifice/endpoint_basic_authentication.rb b/spec/bundler/support/artifice/endpoint_basic_authentication.rb
new file mode 100644
index 0000000000..9fafd51a3d
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_basic_authentication.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointBasicAuthentication < Endpoint
+  before do
+    unless env["HTTP_AUTHORIZATION"]
+      halt 401, "Authentication info not supplied"
+    end
+  end
+end
+
+Artifice.activate_with(EndpointBasicAuthentication)
diff --git a/spec/bundler/support/artifice/endpoint_creds_diff_host.rb b/spec/bundler/support/artifice/endpoint_creds_diff_host.rb
new file mode 100644
index 0000000000..cd152848fe
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_creds_diff_host.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointCredsDiffHost < Endpoint
+  helpers do
+    def auth
+      @auth ||= Rack::Auth::Basic::Request.new(request.env)
+    end
+
+    def authorized?
+      auth.provided? && auth.basic? && auth.credentials && auth.credentials == %w(user pass)
+    end
+
+    def protected!
+      return if authorized?
+      response["WWW-Authenticate"] = %(Basic realm="Testing HTTP Auth")
+      throw(:halt, [401, "Not authorized\n"])
+    end
+  end
+
+  before do
+    protected! unless request.path_info.include?("/no/creds/")
+  end
+
+  get "/gems/:id" do
+    redirect "http://diffhost.com/no/creds/#{params[:id]}"
+  end
+
+  get "/no/creds/:id" do
+    if request.host.include?("diffhost") && !auth.provided?
+      File.read("#{gem_repo1}/gems/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(EndpointCredsDiffHost)
diff --git a/spec/bundler/support/artifice/endpoint_extra.rb b/spec/bundler/support/artifice/endpoint_extra.rb
new file mode 100644
index 0000000000..ed4e87e65f
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_extra.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointExtra < Endpoint
+  get "/extra/api/v1/dependencies" do
+    halt 404
+  end
+
+  get "/extra/specs.4.8.gz" do
+    File.read("#{gem_repo2}/specs.4.8.gz")
+  end
+
+  get "/extra/prerelease_specs.4.8.gz" do
+    File.read("#{gem_repo2}/prerelease_specs.4.8.gz")
+  end
+
+  get "/extra/quick/Marshal.4.8/:id" do
+    redirect "/extra/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/extra/fetch/actual/gem/:id" do
+    File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+  end
+
+  get "/extra/gems/:id" do
+    File.read("#{gem_repo2}/gems/#{params[:id]}")
+  end
+end
+
+Artifice.activate_with(EndpointExtra)
diff --git a/spec/bundler/support/artifice/endpoint_extra_api.rb b/spec/bundler/support/artifice/endpoint_extra_api.rb
new file mode 100644
index 0000000000..1e9e1dc60d
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_extra_api.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointExtraApi < Endpoint
+  get "/extra/api/v1/dependencies" do
+    deps = dependencies_for(params[:gems], gem_repo4)
+    Marshal.dump(deps)
+  end
+
+  get "/extra/specs.4.8.gz" do
+    File.read("#{gem_repo4}/specs.4.8.gz")
+  end
+
+  get "/extra/prerelease_specs.4.8.gz" do
+    File.read("#{gem_repo4}/prerelease_specs.4.8.gz")
+  end
+
+  get "/extra/quick/Marshal.4.8/:id" do
+    redirect "/extra/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/extra/fetch/actual/gem/:id" do
+    File.read("#{gem_repo4}/quick/Marshal.4.8/#{params[:id]}")
+  end
+
+  get "/extra/gems/:id" do
+    File.read("#{gem_repo4}/gems/#{params[:id]}")
+  end
+end
+
+Artifice.activate_with(EndpointExtraApi)
diff --git a/spec/bundler/support/artifice/endpoint_extra_missing.rb b/spec/bundler/support/artifice/endpoint_extra_missing.rb
new file mode 100644
index 0000000000..dc79705a26
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_extra_missing.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint_extra", __FILE__)
+
+Artifice.deactivate
+
+class EndpointExtraMissing < EndpointExtra
+  get "/extra/fetch/actual/gem/:id" do
+    if params[:id] == "missing-1.0.gemspec.rz"
+      halt 404
+    else
+      File.read("#{gem_repo2}/quick/Marshal.4.8/#{params[:id]}")
+    end
+  end
+end
+
+Artifice.activate_with(EndpointExtraMissing)
diff --git a/spec/bundler/support/artifice/endpoint_fallback.rb b/spec/bundler/support/artifice/endpoint_fallback.rb
new file mode 100644
index 0000000000..8a85a41784
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_fallback.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointFallback < Endpoint
+  DEPENDENCY_LIMIT = 60
+
+  get "/api/v1/dependencies" do
+    if params[:gems] && params[:gems].size <= DEPENDENCY_LIMIT
+      Marshal.dump(dependencies_for(params[:gems]))
+    else
+      halt 413, "Too many gems to resolve, please request less than #{DEPENDENCY_LIMIT} gems"
+    end
+  end
+end
+
+Artifice.activate_with(EndpointFallback)
diff --git a/spec/bundler/support/artifice/endpoint_host_redirect.rb b/spec/bundler/support/artifice/endpoint_host_redirect.rb
new file mode 100644
index 0000000000..250416d8cc
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_host_redirect.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointHostRedirect < Endpoint
+  get "/fetch/actual/gem/:id", :host_name => "localgemserver.test" do
+    redirect "http://bundler.localgemserver.test#{request.path_info}"
+  end
+
+  get "/api/v1/dependencies" do
+    status 404
+  end
+end
+
+Artifice.activate_with(EndpointHostRedirect)
diff --git a/spec/bundler/support/artifice/endpoint_marshal_fail.rb b/spec/bundler/support/artifice/endpoint_marshal_fail.rb
new file mode 100644
index 0000000000..0fb75ebf31
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_marshal_fail.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint_fallback", __FILE__)
+
+Artifice.deactivate
+
+class EndpointMarshalFail < EndpointFallback
+  get "/api/v1/dependencies" do
+    "f0283y01hasf"
+  end
+end
+
+Artifice.activate_with(EndpointMarshalFail)
diff --git a/spec/bundler/support/artifice/endpoint_mirror_source.rb b/spec/bundler/support/artifice/endpoint_mirror_source.rb
new file mode 100644
index 0000000000..9fb58ecb29
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_mirror_source.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+class EndpointMirrorSource < Endpoint
+  get "/gems/:id" do
+    if request.env["HTTP_X_GEMFILE_SOURCE"] == "https://server.example.org/"
+      File.read("#{gem_repo1}/gems/#{params[:id]}")
+    else
+      halt 500
+    end
+  end
+end
+
+Artifice.activate_with(EndpointMirrorSource)
diff --git a/spec/bundler/support/artifice/endpoint_redirect.rb b/spec/bundler/support/artifice/endpoint_redirect.rb
new file mode 100644
index 0000000000..f80d7600c2
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_redirect.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointRedirect < Endpoint
+  get "/fetch/actual/gem/:id" do
+    redirect "/fetch/actual/gem/#{params[:id]}"
+  end
+
+  get "/api/v1/dependencies" do
+    status 404
+  end
+end
+
+Artifice.activate_with(EndpointRedirect)
diff --git a/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb b/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb
new file mode 100644
index 0000000000..4b32cbbf5b
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint", __FILE__)
+
+Artifice.deactivate
+
+class EndpointStrictBasicAuthentication < Endpoint
+  before do
+    unless env["HTTP_AUTHORIZATION"]
+      halt 401, "Authentication info not supplied"
+    end
+
+    # Only accepts password == "password"
+    unless env["HTTP_AUTHORIZATION"] == "Basic dXNlcjpwYXNz"
+      halt 403, "Authentication failed"
+    end
+  end
+end
+
+Artifice.activate_with(EndpointStrictBasicAuthentication)
diff --git a/spec/bundler/support/artifice/endpoint_timeout.rb b/spec/bundler/support/artifice/endpoint_timeout.rb
new file mode 100644
index 0000000000..b15650f226
--- /dev/null
+++ b/spec/bundler/support/artifice/endpoint_timeout.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+require File.expand_path("../endpoint_fallback", __FILE__)
+
+Artifice.deactivate
+
+class EndpointTimeout < EndpointFallback
+  SLEEP_TIMEOUT = 15
+
+  get "/api/v1/dependencies" do
+    sleep(SLEEP_TIMEOUT)
+  end
+end
+
+Artifice.activate_with(EndpointTimeout)
diff --git a/spec/bundler/support/artifice/fail.rb b/spec/bundler/support/artifice/fail.rb
new file mode 100644
index 0000000000..1059c6df4e
--- /dev/null
+++ b/spec/bundler/support/artifice/fail.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+require "net/http"
+begin
+  require "net/https"
+rescue LoadError
+  nil # net/https or openssl
+end
+
+# We can't use artifice here because it uses rack
+
+module Artifice; end # for < 2.0, Net::HTTP::Persistent::SSLReuse
+
+class Fail < Net::HTTP
+  # Net::HTTP uses a @newimpl instance variable to decide whether
+  # to use a legacy implementation. Since we are subclassing
+  # Net::HTTP, we must set it
+  @newimpl = true
+
+  def request(req, body = nil, &block)
+    raise(exception(req))
+  end
+
+  # Ensure we don't start a connect here
+  def connect
+  end
+
+  def exception(req)
+    name = ENV.fetch("BUNDLER_SPEC_EXCEPTION") { "Errno::ENETUNREACH" }
+    const = name.split("::").reduce(Object) {|mod, sym| mod.const_get(sym) }
+    const.new("host down: Bundler spec artifice fail! #{req["PATH_INFO"]}")
+  end
+end
+
+# Replace Net::HTTP with our failing subclass
+::Net.class_eval do
+  remove_const(:HTTP)
+  const_set(:HTTP, ::Fail)
+end
diff --git a/spec/bundler/support/artifice/windows.rb b/spec/bundler/support/artifice/windows.rb
new file mode 100644
index 0000000000..c18ca454ec
--- /dev/null
+++ b/spec/bundler/support/artifice/windows.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+require File.expand_path("../../path.rb", __FILE__)
+include Spec::Path
+
+$LOAD_PATH.unshift Dir[base_system_gems.join("gems/artifice*/lib")].first.to_s
+$LOAD_PATH.unshift(*Dir[base_system_gems.join("gems/rack-*/lib")])
+$LOAD_PATH.unshift Dir[base_system_gems.join("gems/tilt*/lib")].first.to_s
+$LOAD_PATH.unshift Dir[base_system_gems.join("gems/sinatra*/lib")].first.to_s
+require "artifice"
+require "sinatra/base"
+
+Artifice.deactivate
+
+class Windows < Sinatra::Base
+  set :raise_errors, true
+  set :show_exceptions, false
+
+  helpers do
+    def gem_repo
+      Pathname.new(ENV["BUNDLER_SPEC_GEM_REPO"] || Spec::Path.gem_repo1)
+    end
+  end
+
+  files = ["specs.4.8.gz",
+           "prerelease_specs.4.8.gz",
+           "quick/Marshal.4.8/rcov-1.0-mswin32.gemspec.rz",
+           "gems/rcov-1.0-mswin32.gem"]
+
+  files.each do |file|
+    get "/#{file}" do
+      File.read gem_repo.join(file)
+    end
+  end
+
+  get "/gems/rcov-1.0-x86-mswin32.gem" do
+    halt 404
+  end
+
+  get "/api/v1/dependencies" do
+    halt 404
+  end
+
+  get "/versions" do
+    halt 500
+  end
+end
+
+Artifice.activate_with(Windows)