(FACT-2826) Added Facter.flush (#2140)

acceptance/tests/facter_flush.rb

@@ -0,0 +1,52 @@
+test_name 'facter should flush fact values' do
+  tag 'risk:high'
+
+  fact_content1 = <<-EOM
+    require 'facter'
+
+    Facter.add(:fact1) do
+      'this should be flushed'
+    end
+
+    Facter.flush
+
+    puts "Fact1: \#\{Facter.value(:fact1)\}"
+  EOM
+
+  fact_content2 = <<-EOM
+    require 'facter'
+
+    Facter.add(:fact2) do
+      on_flush do
+        puts 'before flush'
+      end
+    end
+
+    Facter.flush
+  EOM
+
+  agents.each do |agent|
+    fact_dir = agent.tmpdir('test_scripts')
+    script_path1 = File.join(fact_dir, 'flush_test1.rb')
+    script_path2 = File.join(fact_dir, 'flush_test2.rb')
+    create_remote_file(agent, script_path1, fact_content1)
+    create_remote_file(agent, script_path2, fact_content2)
+
+    teardown do
+      agent.rm_rf(script_path1)
+      agent.rm_rf(script_path2)
+    end
+
+    step 'fact value has been flushed' do
+      on(agent, "#{ruby_command(agent)} #{script_path1}") do |ruby_result|
+        assert_equal('Fact1: ', ruby_result.stdout.chomp)
+      end
+    end
+
+    step 'prints on_flush block gets called' do
+      on(agent, "#{ruby_command(agent)} #{script_path2}") do |ruby_result|
+        assert_equal('before flush', ruby_result.stdout.chomp)
+      end
+    end
+  end
+end

lib/facter.rb

@@ -227,6 +227,18 @@ def reset
       nil
     end
 
+    # Flushes cached values for all facts. This does not cause code to be
+    # reloaded; it only clears the cached results.
+    #
+    # @return [void]
+    #
+    # @api public
+    def flush
+      LegacyFacter.flush
+      SessionCache.invalidate_all_caches
+      nil
+    end
+
     # Loads all facts
     #
     # @return [nil]

spec/facter/facter_spec.rb

@@ -403,6 +403,24 @@ def mock_collection(method, os_name = nil, error = nil)
       end
     end
 
+    describe '#flush' do
+      it 'sends call to LegacyFacter' do
+        allow(LegacyFacter).to receive(:flush)
+
+        Facter.flush
+
+        expect(LegacyFacter).to have_received(:flush).once
+      end
+
+      it 'invalidates core cache' do
+        allow(Facter::SessionCache).to receive(:invalidate_all_caches)
+
+        Facter.flush
+
+        expect(Facter::SessionCache).to have_received(:invalidate_all_caches)
+      end
+    end
+
     describe '#search' do
       it 'sends call to Facter::Options' do
         allow(Facter::Options).to receive(:[]=)