Fix down and up methods (#288)

* Fix down and up methods. Addresses discussion #274

* Add TODO

Author: route

lib/ferrum/keyboard.rb

@@ -31,14 +31,14 @@ def initialize(page)
     end
 
     def down(key)
-      key = normalize_keys(Array(key))
+      key = normalize_keys(Array(key)).first
       type = key[:text] ? "keyDown" : "rawKeyDown"
       @page.command("Input.dispatchKeyEvent", slowmoable: true, type: type, **key)
       self
     end
 
     def up(key)
-      key = normalize_keys(Array(key))
+      key = normalize_keys(Array(key)).first
       @page.command("Input.dispatchKeyEvent", slowmoable: true, type: "keyUp", **key)
       self
     end
@@ -61,9 +61,14 @@ def modifiers(keys)
 
     private
 
+    # TODO: Refactor it, and try to simplify complexity
+    # rubocop:disable Metrics/PerceivedComplexity
+    # rubocop:disable Metrics/CyclomaticComplexity
     def normalize_keys(keys, pressed_keys = [], memo = [])
       case keys
       when Array
+        raise ArgumentError, "empty keys passed" if keys.empty?
+
         pressed_keys.push([])
         memo += combine_strings(keys).map do |key|
           normalize_keys(key, pressed_keys, memo)
@@ -82,6 +87,8 @@ def normalize_keys(keys, pressed_keys = [], memo = [])
           to_options(key)
         end
       when String
+        raise ArgumentError, "empty keys passed" if keys.empty?
+
         pressed = pressed_keys.flatten
         keys.each_char.map do |char|
           key = KEYS[char] || {}
@@ -102,8 +109,12 @@ def normalize_keys(keys, pressed_keys = [], memo = [])
             modifiers + [to_options(key)]
           end.flatten
         end
+      else
+        raise ArgumentError, "unexpected argument"
       end
     end
+    # rubocop:enable Metrics/PerceivedComplexity
+    # rubocop:enable Metrics/CyclomaticComplexity
 
     def combine_strings(keys)
       keys

spec/keyboard_spec.rb

@@ -164,7 +164,7 @@ module Ferrum
       end
     end
 
-    context "type" do
+    context "#type" do
       let(:delete_all) { [[(Utils::Platform.mac? ? :alt : :ctrl), :shift, :right], :backspace] }
 
       before { browser.go_to("/ferrum/set") }
@@ -235,6 +235,30 @@ module Ferrum
       end
     end
 
+    context "#down" do
+      before { browser.go_to("/ferrum/set") }
+
+      it "sends down events from keyboard" do
+        expect { browser.keyboard.down("") }.to raise_error(ArgumentError, "empty keys passed")
+        expect { browser.keyboard.down([]) }.to raise_error(ArgumentError, "empty keys passed")
+        expect { browser.keyboard.down("arghhh") }.not_to raise_error
+        expect { browser.keyboard.down(:page_down) }.not_to raise_error
+        expect { browser.keyboard.down(1) }.to raise_error(ArgumentError, "unexpected argument")
+      end
+    end
+
+    context "#up" do
+      before { browser.go_to("/ferrum/set") }
+
+      it "sends up events from keyboard" do
+        expect { browser.keyboard.up("") }.to raise_error(ArgumentError, "empty keys passed")
+        expect { browser.keyboard.up([]) }.to raise_error(ArgumentError, "empty keys passed")
+        expect { browser.keyboard.up("arghhh") }.not_to raise_error
+        expect { browser.keyboard.up(:page_down) }.not_to raise_error
+        expect { browser.keyboard.up(1) }.to raise_error(ArgumentError, "unexpected argument")
+      end
+    end
+
     describe "events" do
       let(:change_me) { browser.at_css("#change_me") }