Allow change chars length and disable strikethrough (#57)

spec/captcha_spec.rb

@@ -12,17 +12,88 @@ describe RuCaptcha do
 
   describe '.create' do
     it 'should len equal config.len' do
-      res = RuCaptcha.create(0)
+      res = RuCaptcha.create(0, 5, 1)
       expect(res.length).to eq(2)
       expect(res[0].length).to eq(5)
       expect(res[1]).not_to eq(nil)
     end
 
     it 'should work with color style' do
-      res = RuCaptcha.create(1)
+      res = RuCaptcha.create(1, 5, 1)
       expect(res.length).to eq(2)
       expect(res[0].length).to eq(5)
       expect(res[1]).not_to eq(nil)
     end
+
+    it 'should raise when length not in 3..7 ' do
+      RuCaptcha.configure do
+        self.length = 2
+      end
+      #expect(RuCaptcha.generate()).to raise_error('length config error, value must in 3..7')
+      expect { RuCaptcha.generate() }.
+        to raise_error('length config error, value must in 3..7')
+      RuCaptcha.configure do
+        self.length = 5
+      end
+    end
+
+    it 'should work when length in 3..7 ' do
+      RuCaptcha.configure do
+        self.length = 5
+      end
+      res = RuCaptcha.generate()
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(5)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should len equal 3' do
+      res = RuCaptcha.create(1, 3, 1)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(3)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should len equal 4' do
+      res = RuCaptcha.create(1, 4, 1)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(4)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should len equal 5' do
+      res = RuCaptcha.create(1, 5, 1)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(5)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should len equal 6' do
+      res = RuCaptcha.create(1, 6, 1)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(6)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should len equal 7' do
+      res = RuCaptcha.create(1, 7, 0)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(7)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should work with line true' do
+      res = RuCaptcha.create(1, 7, 1)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(7)
+      expect(res[1]).not_to eq(nil)
+    end
+
+    it 'should work with line false' do
+      res = RuCaptcha.create(1, 7, 0)
+      expect(res.length).to eq(2)
+      expect(res[0].length).to eq(7)
+      expect(res[1]).not_to eq(nil)
+    end
   end
 end