simplify lockfile definitions

by avoiding constants

also don't add the alternate lockfiles unless we actually are the
primary gemfile (fixes ruby-lsp)

Change-Id: Icaa47ea81a35938da335b7d5632e04f2d76b1e8c
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/329543
Reviewed-by: Jacob Burroughs <jburroughs@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
Build-Review: Cody Cutrer <cody@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

.rubocop.yml

@@ -459,6 +459,8 @@ Style/FormatString:
   Severity: convention
   AutoCorrect: false
 Style/GlobalVars:
+  AllowedVariables:
+  - $canvas_rails
   Severity: convention
 Style/GuardClause:
   Enabled: false

Gemfile

@@ -25,37 +25,33 @@ Plugin.send(:load_plugin, "bundler-multilock")
 
 require_relative "config/canvas_rails_switcher"
 
-# Bundler evaluates this from a non-global context for plugins, so we have
-# to explicitly pop up to set global constants
-# rubocop:disable Style/RedundantConstantBase
+if Bundler.default_gemfile == gemfile
+  SUPPORTED_RAILS_VERSIONS.product([nil, true]).each do |rails_version, include_plugins|
+    lockfile = ["rails#{rails_version.delete(".")}", include_plugins && "plugins"].compact.join(".")
+    if rails_version == SUPPORTED_RAILS_VERSIONS.first
+      lockfile = nil unless include_plugins
+    elsif include_plugins
+      parent = "rails#{rails_versions.delete(".")}"
+    end
 
-# will already be defined during the second Gemfile evaluation
-::CANVAS_INCLUDE_PLUGINS = true unless defined?(::CANVAS_INCLUDE_PLUGINS)
+    active = rails_version == $canvas_rails && !!include_plugins
 
-SUPPORTED_RAILS_VERSIONS.product([nil, true]).each do |rails_version, include_plugins|
-  lockfile = ["rails#{rails_version.delete(".")}", include_plugins && "plugins"].compact.join(".")
-  lockfile = nil if rails_version == SUPPORTED_RAILS_VERSIONS.first && !include_plugins
+    lockfile(lockfile,
+             active:,
+             parent:,
+             enforce_pinned_additional_dependencies: include_plugins) do
+      $canvas_rails = rails_version
+      @include_plugins = include_plugins
+    end
+  end
 
-  active = rails_version == CANVAS_RAILS && !!include_plugins
-
-  lockfile(lockfile,
-           active:,
-           allow_mismatched_dependencies: rails_version != SUPPORTED_RAILS_VERSIONS.first,
-           enforce_pinned_additional_dependencies: include_plugins) do
-    Object.send(:remove_const, :CANVAS_RAILS)
-    ::CANVAS_RAILS = rails_version
-    Object.send(:remove_const, :CANVAS_INCLUDE_PLUGINS)
-    ::CANVAS_INCLUDE_PLUGINS = include_plugins
+  (gemfile_root.glob("Gemfile.d/*.lock") + gemfile_root.glob("gems/*/Gemfile.lock")).each do |gem_lockfile_name|
+    return unless lockfile(gem_lockfile_name,
+                           gemfile: gem_lockfile_name.to_s.sub(/\.lock$/, ""),
+                           allow_mismatched_dependencies: false)
   end
 end
 
-(gemfile_root.glob("Gemfile.d/*.lock") + gemfile_root.glob("gems/*/Gemfile.lock")).each do |gem_lockfile_name|
-  return unless lockfile(gem_lockfile_name,
-                         gemfile: gem_lockfile_name.to_s.sub(/\.lock$/, ""),
-                         allow_mismatched_dependencies: false)
-end
-# rubocop:enable Style/RedundantConstantBase
-
 module PreferGlobalRubyGemsSource
   def rubygems_sources
     [global_rubygems_source] + non_global_rubygems_sources
@@ -80,7 +76,7 @@ module GemOverride
 end
 Bundler::Dsl.prepend(GemOverride)
 
-if CANVAS_INCLUDE_PLUGINS
+if @include_plugins
   gemfile_root.glob("gems/plugins/*/Gemfile.d/_before.rb") do |file|
     eval_gemfile(file)
   end

Gemfile.d/plugins.rb

@@ -17,7 +17,7 @@
 # You should have received a copy of the GNU Affero General Public License along
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 
-CANVAS_INLINE_PLUGINS = %w[
+inline_plugins = %w[
   academic_benchmark
   account_reports
   moodle_importer
@@ -30,7 +30,7 @@ gemfile_root.glob("../gems/plugins/*") do |plugin_dir|
   next unless File.directory?(plugin_dir)
 
   gem_name = File.basename(plugin_dir)
-  next unless CANVAS_INCLUDE_PLUGINS || CANVAS_INLINE_PLUGINS.include?(gem_name)
+  next unless @include_plugins || inline_plugins.include?(gem_name)
 
   gem(gem_name, path: plugin_dir.relative_path_from(gemfile_root))
 end

Gemfile.d/~after.rb

@@ -20,7 +20,7 @@
 # Non-standard Canvas extension to Bundler behavior -- load the Gemfiles from
 # plugins.
 
-if CANVAS_INCLUDE_PLUGINS
+if @include_plugins
   gemfile_root.glob("../gems/plugins/*/Gemfile.d/*") do |g|
     next if g.basename == "_before.rb"
 

config/canvas_rails_switcher.rb

@@ -29,13 +29,13 @@
 # the default version (corresponding to the bare Gemfile.lock) must be listed first
 SUPPORTED_RAILS_VERSIONS = %w[7.0].freeze
 
-unless defined?(CANVAS_RAILS)
+unless defined?($canvas_rails)
   file_path = File.expand_path("RAILS_VERSION", __dir__)
 
   if ENV["CANVAS_RAILS"]
-    CANVAS_RAILS = ENV["CANVAS_RAILS"]
+    $canvas_rails = ENV["CANVAS_RAILS"]
   elsif File.exist?(file_path)
-    CANVAS_RAILS = File.read(file_path).strip
+    $canvas_rails = File.read(file_path).strip
   else
     begin
       # have to do the consul communication without any gems, because
@@ -63,13 +63,13 @@ unless defined?(CANVAS_RAILS)
           break if result
         end
       end
-      CANVAS_RAILS = result ? Base64.decode64(JSON.parse(result.body).first["Value"]).strip : SUPPORTED_RAILS_VERSIONS.first
+      $canvas_rails = result ? Base64.decode64(JSON.parse(result.body).first["Value"]).strip : SUPPORTED_RAILS_VERSIONS.first
     rescue
-      CANVAS_RAILS = SUPPORTED_RAILS_VERSIONS.first
+      $canvas_rails = SUPPORTED_RAILS_VERSIONS.first
     end
   end
 end
 
-unless SUPPORTED_RAILS_VERSIONS.any?(CANVAS_RAILS)
-  raise "unsupported Rails version specified #{CANVAS_RAILS}"
+unless SUPPORTED_RAILS_VERSIONS.any?($canvas_rails)
+  raise "unsupported Rails version specified #{$canvas_rails}"
 end