closes #155

catmando · catmando · commit 3495f4be3f5b · 2016-07-18T15:26:18.000-04:00
diff --git a/.rubocop.yml b/.rubocop.yml
@@ -6,3 +6,6 @@ Style/MutableConstant:
 
 Lint/LiteralInCondition:
   Enabled: false
+
+Style/CommandLiteral:
+  EnforcedStyle: mixed
diff --git a/lib/react/component.rb b/lib/react/component.rb
@@ -90,32 +90,49 @@ def component_will_receive_props(next_props)
       self.class.process_exception(e, self)
     end
 
-    def props_changed?(next_props)
-      return true unless props.keys.sort == next_props.keys.sort
-      props.detect { |k, v| `#{next_props[k]} != #{params[k]}`}
-    end
-
-    def should_component_update?(next_props, next_state)
+    def should_component_update?(native_next_props, native_next_state)
       State.set_state_context_to(self) do
-        next_props = Hash.new(next_props)
-        if self.respond_to?(:needs_update?)
-          !!self.needs_update?(next_props, Hash.new(next_state))
-        elsif false # switch to true to force updates per standard react
-          true
-        elsif props_changed? next_props
-          true
-        elsif `!next_state != !#{@native}.state`
-          true
-        elsif `!next_state && !#{@native}.state`
-          false
-        elsif `next_state["***_state_updated_at-***"] != #{@native}.state["***_state_updated_at-***"]`
-          true
+        next_params = Hash.new(native_next_props)
+        if respond_to?(:needs_update?)
+          call_needs_update(next_params, native_next_state)
         else
-          false
+          !!(props_changed?(next_params) || native_state_changed?(native_next_state))
         end.to_n
       end
     end
 
+    def call_needs_update(next_params, native_next_state)
+      component = self
+      next_params.define_singleton_method(:changed?) do
+        @changing ||= component.props_changed?(self)
+      end
+      next_state = Hash.new(native_next_state)
+      next_state.define_singleton_method(:changed?) do
+        @changing ||= component.native_state_changed?(native_next_state)
+      end
+      !!needs_update?(next_params, next_state)
+    end
+
+    def native_state_changed?(next_state)
+      %x{
+        var normalized_next_state =
+          (!#{next_state} || Object.keys(#{next_state}).length === 0 || #{nil} == next_state) ? false : #{next_state}
+        var normalized_current_state =
+          (!#{@native}.state || Object.keys(#{@native}.state).length === 0 || #{nil} == #{@native}.state) ? false : #{@native}.state
+        if (!normalized_current_state != !normalized_next_state) return(true)
+        if (!normalized_current_state && !normalized_next_state) return(false)
+        if (!normalized_current_state['***_state_updated_at-***'] ||
+            !normalized_next_state['***_state_updated_at-***']) return(true)
+        return (normalized_current_state['***_state_updated_at-***'] !=
+                normalized_next_state['***_state_updated_at-***'])
+      }
+    end
+
+    def props_changed?(next_params)
+      (props.keys.sort != next_params.keys.sort) ||
+        next_params.detect { |k, _v| `#{next_params[k]} != #{@native}.props[#{k}]` }
+    end
+
     def component_will_update(next_props, next_state)
       State.set_state_context_to(self) { self.run_callback(:before_update, Hash.new(next_props), Hash.new(next_state)) }
       @props_wrapper = self.class.props_wrapper.new(Hash.new(next_props), @props_wrapper)
diff --git a/spec/react/component_spec.rb b/spec/react/component_spec.rb
@@ -705,6 +705,79 @@ def render
     end
   end
 
+  describe '.params_changed?' do
+
+    before(:each) do
+      stub_const 'Foo', Class.new(React::Component::Base)
+      Foo.define_method :needs_update? do |next_params, next_state|
+        next_params.changed?
+      end
+      @foo = Foo.new
+    end
+
+    it "returns false if new and old params are the same" do
+      @foo.instance_variable_set("@native", `{props: {value1: 1, value2: 2}}`)
+      expect(@foo.should_component_update?(`{value2: 2, value1: 1}`, `null`)).to be_falsy
+    end
+
+    it "returns true if new and old params are have different values" do
+      @foo.instance_variable_set("@native", `{props: {value1: 1, value2: 2}}`)
+      expect(@foo.should_component_update?(`{value2: 2, value1: 2}`, `null`)).to be_truthy
+    end
+
+    it "returns true if new and old params are have different keys" do
+      @foo.instance_variable_set("@native", `{props: {value1: 1, value2: 2}}`)
+      expect(@foo.should_component_update?(`{value2: 2, value1: 1, value3: 3}`, `null`)).to be_truthy
+    end
+  end
+
+  describe '#state_changed?' do
+
+    empties = [`{}`, `undefined`, `null`, `false`]
+
+    before(:each) do
+      stub_const 'Foo', Class.new(React::Component::Base)
+      Foo.define_method :needs_update? do |next_params, next_state|
+        next_state.changed?
+      end
+      @foo = Foo.new
+    end
+
+    it "returns false if both new and old states are empty" do
+      empties.each do |empty1|
+        empties.each do |empty2|
+          @foo.instance_variable_set("@native", `{state: #{empty1}}`)
+          expect(@foo.should_component_update?(`{}`, empty2)).to be_falsy
+        end
+      end
+    end
+
+    it "returns true if old state is empty, but new state is not" do
+      empties.each do |empty|
+        @foo.instance_variable_set("@native", `{state: #{empty}}`)
+        expect(@foo.should_component_update?(`{}`, `{foo: 12}`)).to be_truthy
+      end
+    end
+
+    it "returns true if new state is empty, but old state is not" do
+      empties.each do |empty|
+        @foo.instance_variable_set("@native", `{state: {foo: 12}}`)
+        expect(@foo.should_component_update?(`{}`, empty)).to be_truthy
+      end
+    end
+
+    it "returns true if new state and old state have different time stamps" do
+      @foo.instance_variable_set("@native", `{state: {'***_state_updated_at-***': 12}}`)
+      expect(@foo.should_component_update?(`{}`, `{'***_state_updated_at-***': 13}`)).to be_truthy
+    end
+
+    it "returns false if new state and old state have the same time stamps" do
+      @foo.instance_variable_set("@native", `{state: {'***_state_updated_at-***': 12}}`)
+      expect(@foo.should_component_update?(`{}`, `{'***_state_updated_at-***': 12}`)).to be_falsy
+    end
+
+  end
+
   describe '#children' do
     before(:each) do
       stub_const 'Foo', Class.new
