Fix vi-mode partial-accept

Issue #188. PR #324.

Thanks to @toadjaune and @IngoHeimbach.

spec/integrations/vi_mode_spec.rb

@@ -17,5 +17,51 @@ describe 'when using vi mode' do
       end
     end
   end
+
+  describe '`vi-forward-word-end`' do
+    it 'should accept through the end of the current word' do
+      with_history('foobar foo') do
+        session.
+          send_string('foo').
+          send_keys('escape').
+          send_keys('e'). # vi-forward-word-end
+          send_keys('a'). # vi-add-next
+          send_string('baz')
+
+        wait_for { session.content }.to eq('foobarbaz')
+      end
+    end
+  end
+
+  describe '`vi-forward-word`' do
+    it 'should accept through the first character of the next word' do
+      with_history('foobar foo') do
+        session.
+          send_string('foo').
+          send_keys('escape').
+          send_keys('w'). # vi-forward-word
+          send_keys('a'). # vi-add-next
+          send_string('az')
+
+        wait_for { session.content }.to eq('foobar faz')
+      end
+    end
+  end
+
+  describe '`vi-find-next-char`' do
+    it 'should accept through the next occurrence of the character' do
+      with_history('foobar foo') do
+        session.
+          send_string('foo').
+          send_keys('escape').
+          send_keys('f'). # vi-find-next-char
+          send_keys('o').
+          send_keys('a'). # vi-add-next
+          send_string('b')
+
+        wait_for { session.content }.to eq('foobar fob')
+      end
+    end
+  end
 end