mapping_rules_matcher: stop when a rule marked as 'last' matches

gateway/src/apicast/mapping_rules_matcher.lua

@@ -27,6 +27,8 @@ function _M.get_usage_from_matches(method, uri, args, rules)
       -- Some rules have no delta. Send 0 in that case.
       usage:add(rule.system_name, rule.delta or 0)
       insert(matched_rules, rule)
+
+      if rule.last then break end
     end
   end
 

spec/mapping_rules_matcher_spec.lua

@@ -4,34 +4,77 @@ describe('mapping_rules_matcher', function()
   local func_true = function() return true end
   local func_false = function() return false end
 
-  -- Test rules. Instead of instantiating mapping rules, we just mock the
-  -- methods and attributes we are interested in, for simplicity.
-  local rule_1 = { matches = func_true, system_name = 'hits', delta = 1 }
-  local rule_2 = { matches = func_false, system_name = 'hits', delta = 2 }
-  local rule_3 = { matches = func_true, system_name = 'hits', delta = 3 }
-  local rules = { rule_1, rule_2, rule_3 }
-
   describe('.get_usage_from_matches', function()
-    local usage, matched_rules = mapping_rules_matcher.get_usage_from_matches(
-      'GET', '/', {}, rules)
+    describe('when rules do not have the "attr" set', function()
+      -- Instead of instantiating mapping rules, we just mock the
+      -- methods and attributes we are interested in, for simplicity.
+      local rule_1 = { matches = func_true, system_name = 'hits', delta = 1 }
+      local rule_2 = { matches = func_false, system_name = 'hits', delta = 2 }
+      local rule_3 = { matches = func_true, system_name = 'hits', delta = 3 }
+      local rules = { rule_1, rule_2, rule_3 }
+
+      local usage, matched_rules = mapping_rules_matcher.get_usage_from_matches(
+        'GET', '/', {}, rules
+      )
+
+      it('returns the usage from matching all the mapping rules', function()
+        assert.same({ hits = 4 }, usage.deltas)
+      end)
 
-    it('returns the usage from matching the mapping rules', function()
-      assert.same({ hits = 4 }, usage.deltas)
+      it('returns all the rules that matched', function()
+        assert.same({ rule_1, rule_3 } , matched_rules)
+      end)
     end)
 
-    it('returns the rules that matched', function()
-      assert.same({ rule_1, rule_3 } , matched_rules)
+    describe('when a rule has the attr "last" set to true', function()
+      describe('and that rule matches', function()
+        it('does not try to match the following ones', function()
+          local rule_1 = { matches = func_true, system_name = 'hits', delta = 1 }
+          local rule_2 = { last = true, matches = func_true, system_name = 'hits', delta = 2 }
+          local rule_3 = { matches = func_true, system_name = 'hits', delta = 5 }
+
+          -- Notice that r3 matches, but r2 is "last", so the usage of r3
+          -- should not be added.
+          local rules = { rule_1, rule_2, rule_3 }
+
+          local usage, matched_rules = mapping_rules_matcher.get_usage_from_matches(
+            'GET', '/', {}, rules
+          )
+
+          assert.same({ hits = rule_1.delta + rule_2.delta }, usage.deltas)
+          assert.same({ rule_1, rule_2 }, matched_rules)
+        end)
+      end)
+
+      describe('and that rule does not match', function()
+        it('continues matching the following ones', function()
+          local rule_1 = { matches = func_true, system_name = 'hits', delta = 1 }
+          local rule_2 = { last = true, matches = func_false, system_name = 'hits', delta = 2 }
+          local rule_3 = { matches = func_true, system_name = 'hits', delta = 5 }
+
+          -- Notice that r2 is "last", but it does not match, so the usage of
+          -- r3 should be added.
+          local rules = { rule_1, rule_2, rule_3 }
+
+          local usage, matched_rules = mapping_rules_matcher.get_usage_from_matches(
+            'GET', '/', {}, rules
+          )
+
+          assert.same({ hits = rule_1.delta + rule_3.delta }, usage.deltas)
+          assert.same({ rule_1, rule_3 }, matched_rules)
+        end)
+      end)
     end)
   end)
 
   describe('.matches', function()
     describe('when there is a match', function()
-      local not_maching_rule = { matches = func_false }
+      local not_matching_rule = { matches = func_false }
       local matching_rule = { matches = func_true }
 
       it('returns true and the index of the first rule that matches', function()
         local matches, index = mapping_rules_matcher.matches(
-          'GET', '/', {}, { not_maching_rule, matching_rule })
+          'GET', '/', {}, { not_matching_rule, matching_rule })
 
         assert.is_true(matches)
         assert.equals(2, index)