Do not allow to set strict via the config file (#4557)

lib/sidekiq/cli.rb

@@ -357,6 +357,12 @@ module Sidekiq
       Sidekiq.logger.level = ::Logger::DEBUG if options[:verbose]
     end
 
+    INTERNAL_OPTIONS = [
+      # These are options that are set internally and cannot be
+      # set via the config file or command line arguments.
+      :strict
+    ]
+
     def parse_config(path)
       opts = YAML.load(ERB.new(File.read(path)).result) || {}
 
@@ -367,6 +373,8 @@ module Sidekiq
       end
 
       opts = opts.merge(opts.delete(environment.to_sym) || {})
+      opts.delete(*INTERNAL_OPTIONS)
+
       parse_queues(opts, opts.delete(:queues) || [])
 
       opts

test/config_with_internal_options.yml

@@ -0,0 +1,11 @@
+---
+:verbose:      false
+:timeout:      10
+:require:      ./test/fake_env.rb
+:concurrency:  50
+:tag:          tag
+:queues:
+  - [often]
+  - [seldom]
+
+:strict:       false

test/test_cli.rb

@@ -62,6 +62,16 @@ describe Sidekiq::CLI do
           end
         end
 
+        describe 'setting internal options via the config file' do
+          describe 'setting the `strict` option via the config file' do
+            it 'discards the `strict` option specified via the config file' do
+              subject.parse(%w[sidekiq -C ./test/config_with_internal_options.yml])
+
+              assert_equal true, !!Sidekiq.options[:strict]
+            end
+          end
+        end
+
         describe 'queues' do
           it 'accepts with -q' do
             subject.parse(%w[sidekiq -q foo -r ./test/fake_env.rb])