test: add template, view, session, and flash tests

test/test_flash.rb

@@ -0,0 +1,69 @@
+require 'minitest/autorun'
+require 'prism'
+
+class FlashTest < Minitest::Test
+  def test_set_value_is_not_visible_in_same_flash_read_before_sweep
+    session = Prism::Params.new
+    flash = Prism::Flash.new(session)
+    flash[:notice] = 'saved'
+    assert_nil flash[:notice], 'value set this request should not be readable via [] until next request'
+  end
+
+  def test_sweep_persists_pending_values_into_session
+    session = Prism::Params.new
+    flash = Prism::Flash.new(session)
+    flash[:notice] = 'saved'
+    flash.sweep
+    assert_equal({ 'notice' => 'saved' }, session['_flash'])
+  end
+
+  def test_next_request_reads_previous_pending_value
+    session = Prism::Params.new
+    first = Prism::Flash.new(session)
+    first[:notice] = 'saved'
+    first.sweep
+
+    second = Prism::Flash.new(session)
+    assert_equal 'saved', second[:notice]
+  end
+
+  def test_flash_does_not_carry_over_a_second_time
+    session = Prism::Params.new
+    first = Prism::Flash.new(session)
+    first[:notice] = 'saved'
+    first.sweep
+
+    second = Prism::Flash.new(session)
+    second[:notice]
+    second.sweep
+
+    third = Prism::Flash.new(session)
+    assert_nil third[:notice]
+  end
+
+  def test_now_reads_current_flash_without_waiting_for_sweep
+    session = Prism::Params.new
+    session['_flash'] = { 'notice' => 'saved' }
+    flash = Prism::Flash.new(session)
+    assert_equal 'saved', flash.now[:notice]
+  end
+
+  def test_keep_carries_current_flash_into_next_request
+    session = Prism::Params.new
+    session['_flash'] = { 'notice' => 'saved' }
+    flash = Prism::Flash.new(session)
+    flash.keep
+    flash.sweep
+
+    next_flash = Prism::Flash.new(session)
+    assert_equal 'saved', next_flash[:notice]
+  end
+
+  def test_empty_predicate
+    session = Prism::Params.new
+    flash = Prism::Flash.new(session)
+    assert flash.empty?
+    session['_flash'] = { 'notice' => 'x' }
+    assert Prism::Flash.new(session).empty? == false
+  end
+end