Use "unknown" for :last_run_status when we don't have a value.

This ensures that the value is consistent — before for an unknown
case it could either be `nil` or `"unknown"`.

We've also moved the constant into configuration, so that we can
avoid the cost of loading `example_status_persister` (via constant
access since it is setup to be autoloaded) if the user hasn't
configured the feature.

Author: myronmarston

lib/rspec/core/configuration.rb

@@ -834,17 +834,19 @@ def files_to_run
 
       # @private
       def last_run_statuses
-        @last_run_statuses ||=
+        @last_run_statuses ||= Hash.new(UNKNOWN_STATUS).tap do |statuses|
           if (path = example_status_persistence_file_path)
-            ExampleStatusPersister.load_from(path).inject({}) do |hash, example|
+            ExampleStatusPersister.load_from(path).inject(statuses) do |hash, example|
               hash[example.fetch(:example_id)] = example.fetch(:status)
               hash
             end
-          else
-            {}
           end
+        end
       end
 
+      # @private
+      UNKNOWN_STATUS = "unknown".freeze
+
       # @private
       FAILED_STATUS = "failed".freeze
 

lib/rspec/core/example_status_persister.rb

@@ -45,7 +45,7 @@ def statuses_from_this_run
 
           {
             :example_id => ex.id,
-            :status     => result.status ? result.status.to_s : ExampleStatusMerger::UNKNOWN_STATUS,
+            :status     => result.status ? result.status.to_s : Configuration::UNKNOWN_STATUS,
             :run_time   => result.run_time ? Formatters::Helpers.format_duration(result.run_time) : ""
           }
         end
@@ -86,12 +86,10 @@ def merge
         delete_previous_examples_that_no_longer_exist
 
         @this_run.merge(@from_previous_runs) do |_ex_id, new, old|
-          new.fetch(:status) == UNKNOWN_STATUS ? old : new
+          new.fetch(:status) == Configuration::UNKNOWN_STATUS ? old : new
         end.values.sort_by(&method(:sort_value_from))
       end
 
-      UNKNOWN_STATUS = "unknown".freeze
-
     private
 
       def hash_from(example_list)

spec/rspec/core/configuration/only_failures_support_spec.rb

@@ -31,21 +31,33 @@ def last_run_statuses
         it 'returns a memoized value' do
           expect(last_run_statuses).to be(last_run_statuses)
         end
+
+        specify 'the hash returns `unknown` for unknown example ids for consistency' do
+          expect(last_run_statuses["foo"]).to eq(Configuration::UNKNOWN_STATUS)
+          expect(last_run_statuses["bar"]).to eq(Configuration::UNKNOWN_STATUS)
+        end
       end
 
       context "when `example_status_persistence_file_path` is not configured" do
+        before do
+          config.example_status_persistence_file_path = nil
+        end
+
         it 'returns a memoized value' do
           expect(last_run_statuses).to be(last_run_statuses)
         end
 
         it 'returns a blank hash without attempting to load the persisted statuses' do
-          config.example_status_persistence_file_path = nil
-
           persister = class_double(ExampleStatusPersister).as_stubbed_const
           expect(persister).not_to receive(:load_from)
 
           expect(last_run_statuses).to eq({})
         end
+
+        specify 'the hash returns `unknown` for all ids for consistency' do
+          expect(last_run_statuses["foo"]).to eq(Configuration::UNKNOWN_STATUS)
+          expect(last_run_statuses["bar"]).to eq(Configuration::UNKNOWN_STATUS)
+        end
       end
 
       def allows_value_to_change_when_updated

spec/rspec/core/example_status_persister_spec.rb

@@ -82,14 +82,14 @@ def new_example(id, metadata = {})
         expect(loaded).to match [ a_hash_including(:run_time => "3 seconds") ]
       end
 
-      it "persists a loaded but unexecuted example with an #{ExampleStatusMerger::UNKNOWN_STATUS} status" do
+      it "persists a loaded but unexecuted example with an #{Configuration::UNKNOWN_STATUS} status" do
         ex_1 = RSpec.describe.example
 
         ExampleStatusPersister.persist([ex_1], file.path)
         loaded = ExampleStatusPersister.load_from(file.path)
 
         expect(loaded).to match [ a_hash_including(
-          :example_id => ex_1.id, :status => ExampleStatusMerger::UNKNOWN_STATUS
+          :example_id => ex_1.id, :status => Configuration::UNKNOWN_STATUS
         ) ]
       end
 
@@ -142,7 +142,7 @@ def new_example(id, metadata = {})
 
     context "for examples that are only in the set for this run" do
       it "takes them indiscriminately, even if they did not execute" do
-        this_run = [ example(existing_spec_file, "1:1", ExampleStatusMerger::UNKNOWN_STATUS) ]
+        this_run = [ example(existing_spec_file, "1:1", Configuration::UNKNOWN_STATUS) ]
 
         merged = merge(:this_run => this_run, :from_previous_runs => [])
         expect(merged).to match_array(this_run)
@@ -187,7 +187,7 @@ def new_example(id, metadata = {})
       end
 
       it "takes the status from previous runs if the example was loaded but did not execute" do
-        this_run           = [ example("foo_spec.rb", "1:1", ExampleStatusMerger::UNKNOWN_STATUS) ]
+        this_run           = [ example("foo_spec.rb", "1:1", Configuration::UNKNOWN_STATUS) ]
         from_previous_runs = [ example("foo_spec.rb", "1:1", "failed") ]
 
         merged = merge(:this_run => this_run, :from_previous_runs => from_previous_runs)