[policy] implement policy equality and tostring

gateway/src/apicast/policy.lua

@@ -18,9 +18,18 @@ local PHASES = {
 
 local setmetatable = setmetatable
 local ipairs = ipairs
+local format = string.format
 
 local noop = function() end
 
+local function __tostring(policy)
+    return format("Policy: %s (%s)", policy._NAME, policy._VERSION)
+end
+
+local function __eq(policy, other)
+    return policy._NAME == other._NAME and policy._VERSION == other._VERSION
+end
+
 --- Initialize new policy
 -- Returns a new policy that you can extend however you want.
 -- @tparam string name Name of the new policy.
@@ -31,7 +40,7 @@ function _M.new(name, version)
         _NAME = name,
         _VERSION = version or '0.0',
     }
-    local mt = { __index = policy }
+    local mt = { __index = policy, __tostring = __tostring, __eq = __eq }
 
     function policy.new()
         return setmetatable({}, mt)
@@ -41,7 +50,7 @@ function _M.new(name, version)
         policy[phase] = noop
     end
 
-    return policy
+    return setmetatable(policy, { __tostring = __tostring, __eq = __eq })
 end
 
 function _M.phases()

spec/policy_spec.lua

@@ -49,6 +49,56 @@ describe('policy', function()
     end)
   end)
 
+  describe('module equality', function()
+    it('equals when name and version are the same', function()
+      local p1 = policy.new('NAME', 'VERSION')
+      local p2 = policy.new('NAME', 'VERSION')
+
+      assert.are.equal(p1, p2)
+      assert.not_same(p1, p2)
+    end)
+
+    it('is not equal when names are different', function()
+      local p1 = policy.new('NAME', 'VERSION')
+      local p2 = policy.new('NAME2', 'VERSION')
+
+      assert.are.not_equal(p1, p2)
+    end)
+
+    it('is not equal when versions are different', function()
+      local p1 = policy.new('NAME', 'VERSION')
+      local p2 = policy.new('NAME', 'VERSION2')
+
+      assert.are.not_equal(p1, p2)
+    end)
+  end)
+
+  describe('module tostring', function()
+    it('shows name and version', function()
+      local p1 = policy.new('NAME', 'VERSION')
+
+      assert.equal('Policy: NAME (VERSION)', tostring(p1))
+    end)
+  end)
+
+  describe('instance equality', function()
+    local p1 = policy.new('NAME', 'VERSION')
+    local p2 = policy.new('NAME', 'VERSION')
+
+    it('equals when name and version are the same', function()
+      assert.are.equal(p1.new(), p1.new())
+      assert.are.equal(p1.new(), p2.new())
+    end)
+  end)
+
+  describe('instance tostring', function()
+    it('shows name and version', function()
+      local p1 = policy.new('NAME', 'VERSION').new()
+
+      assert.equal('Policy: NAME (VERSION)', tostring(p1))
+    end)
+  end)
+
   describe('.phases', function()
     it('returns the nginx phases where policies can run, sorted by order of execution', function()
       local res = {}