Raise on usage of metadata on suite-level scopes

Author: pirj

Changelog.md

@@ -10,6 +10,7 @@ Breaking Changes:
   and remove the configuration option. (Phil Pirozhkov, #2834)
 * Remove `run_all_when_everything_filtered` configuration option. (Phil Pirozhkov, #2845)
 * Raise on unsupported hook scope usage. (Phil Pirozhkov, #2849)
+* Raise on usage of metadata on suite-level scopes. (Phil Pirozhkov, #2849)
 
 Enhancements:
 

lib/rspec/core/configuration.rb

@@ -1990,9 +1990,7 @@ def handle_suite_hook(scope, meta)
         return nil unless scope == :suite
 
         unless meta.empty?
-          # TODO: in RSpec 4, consider raising an error here.
-          # We warn only for backwards compatibility.
-          RSpec.warn_with "WARNING: `:suite` hooks do not support metadata since " \
+          raise ArgumentError, "WARNING: `:suite` hooks do not support metadata since " \
                           "they apply to the suite as a whole rather than " \
                           "any individual example or example group that has metadata. " \
                           "The metadata you have provided (#{meta.inspect}) will be ignored."

spec/rspec/core/suite_hooks_spec.rb

@@ -76,12 +76,12 @@ module RSpec::Core
         end
 
         context "registered with metadata" do
-          it "explicitly warns that the metadata is ignored" do
+          it "raises an error" do
             expect {
               RSpec.configure do |c|
                 c.__send__(registration_method, :suite, :some => :metadata)
               end
-            }.to output(a_string_including(":suite", "metadata")).to_stderr
+            }.to raise_error(ArgumentError, a_string_including(":suite", "metadata"))
           end
         end
       end
@@ -108,17 +108,6 @@ def define_and_run_example_group(&block)
         runner.run err, out
       end
 
-      it "still runs :suite hooks with metadata even though the metadata is ignored" do
-        sequence = []
-        allow(RSpec).to receive(:warn_with)
-
-        config.before(:suite, :foo)  { sequence << :before_suite   }
-        config.after(:suite, :foo)   { sequence << :after_suite    }
-        define_and_run_example_group { sequence << :example_groups }
-
-        expect(sequence).to eq([ :before_suite, :example_groups, :after_suite ])
-      end
-
       it "runs :suite hooks before and after example groups in the correct order" do
         sequence = []