Fix: scroller for descending (#327)

lua/tests/automated/scroller_spec.lua

@@ -5,8 +5,8 @@ local eq = assert.are.same
 describe('scroller', function()
   local max_results = 10
 
-  describe('cycle', function()
-    local cycle_scroller = p_scroller.create('cycle')
+  describe('ascending cycle', function()
+    local cycle_scroller = p_scroller.create('cycle', 'ascending')
 
     it('should return values within the max results', function()
       eq(5, cycle_scroller(max_results, max_results, 5))
@@ -29,8 +29,8 @@ describe('scroller', function()
     end)
   end)
 
-  describe('other', function()
-    local limit_scroller = p_scroller.create('limit')
+  describe('ascending limit', function()
+    local limit_scroller = p_scroller.create('limit', 'ascending')
 
     it('should return values within the max results', function()
       eq(5, limit_scroller(max_results, max_results, 5))
@@ -44,7 +44,7 @@ describe('scroller', function()
       eq(0, limit_scroller(max_results, max_results, -1))
     end)
 
-    it('should cycle you to 0 when you go past the results', function()
+    it('should not cycle you to 0 when you go past the results', function()
       eq(max_results - 1, limit_scroller(max_results, max_results, max_results + 1))
     end)
 
@@ -53,4 +53,53 @@ describe('scroller', function()
       eq(current - 1, limit_scroller(max_results, current, 7))
     end)
   end)
+
+  describe('descending cycle', function()
+    local cycle_scroller = p_scroller.create('cycle', 'descending')
+
+    it('should return values within the max results', function()
+      eq(5, cycle_scroller(max_results, max_results, 5))
+    end)
+
+    it('should return max_results - 1 at 0', function()
+      eq(0, cycle_scroller(max_results, max_results, 0))
+    end)
+
+    it('should cycle you to the bot when you go below 0', function()
+      eq(max_results - 1, cycle_scroller(max_results, max_results, -1))
+    end)
+
+    it('should cycle you to 0 when you go past the results', function()
+      eq(0, cycle_scroller(max_results, max_results, max_results + 1))
+    end)
+
+    it('should cycle when current results is less than max_results', function()
+      eq(9, cycle_scroller(max_results, 5, 4))
+    end)
+  end)
+
+  describe('descending limit', function()
+    local limit_scroller = p_scroller.create('limit', 'descending')
+
+    it('should return values within the max results', function()
+      eq(5, limit_scroller(max_results, max_results, 5))
+    end)
+
+    it('should return 0 at 0', function()
+      eq(0, limit_scroller(max_results, max_results, 0))
+    end)
+
+    it('should not cycle', function()
+      eq(0, limit_scroller(max_results, max_results, -1))
+    end)
+
+    it('should not cycle you to 0 when you go past the results', function()
+      eq(max_results - 1, limit_scroller(max_results, max_results, max_results + 1))
+    end)
+
+    it('should stay at current results when current results is less than max_results', function()
+      local current = 5
+      eq(current - 1, limit_scroller(max_results, current, 4))
+    end)
+  end)
 end)