feat(pdk): increase the precision of JSON number encoding from 14 to 16 decimals

changelog/unreleased/kong/pdk-json-encoding-numbers-precision.yml

@@ -0,0 +1,3 @@
+message: Increase the precision of JSON number encoding from 14 to 16 decimals
+type: feature
+scope: PDK

kong-3.6.0-0.rockspec

@@ -180,6 +180,7 @@ build = {
     ["kong.tools.module"] = "kong/tools/module.lua",
     ["kong.tools.ip"] = "kong/tools/ip.lua",
     ["kong.tools.http"] = "kong/tools/http.lua",
+    ["kong.tools.cjson"] = "kong/tools/cjson.lua",
 
     ["kong.runloop.handler"] = "kong/runloop/handler.lua",
     ["kong.runloop.events"] = "kong/runloop/events.lua",

kong/constants.lua

@@ -92,6 +92,7 @@ for k in pairs(key_formats_map) do
 end
 
 local constants = {
+  CJSON_MAX_PRECISION = 16,
   BUNDLED_PLUGINS = plugin_map,
   DEPRECATED_PLUGINS = deprecated_plugin_map,
   BUNDLED_VAULTS = vault_map,

kong/db/strategies/postgres/init.lua

@@ -1,6 +1,5 @@
 local arrays        = require "pgmoon.arrays"
 local json          = require "pgmoon.json"
-local cjson         = require "cjson"
 local cjson_safe    = require "cjson.safe"
 local utils         = require "kong.tools.utils"
 local new_tab       = require "table.new"
@@ -180,6 +179,10 @@ local function escape_literal(connector, literal, field)
       return concat { "TO_TIMESTAMP(", connector:escape_literal(tonumber(fmt("%.3f", literal))), ") AT TIME ZONE 'UTC'" }
     end
 
+    if field.type == "integer" then
+      return fmt("%16.f", literal)
+    end
+
     if field.type == "array" or field.type == "set" then
       if not literal[1] then
         return connector:escape_literal("{}")
@@ -211,7 +214,7 @@ local function escape_literal(connector, literal, field)
       elseif et == "map" or et == "record" or et == "json" then
         local jsons = {}
         for i, v in ipairs(literal) do
-          jsons[i] = cjson.encode(v)
+          jsons[i] = cjson_safe.encode(v)
         end
         return encode_array(jsons) .. '::JSONB[]'
 
@@ -522,7 +525,7 @@ local function page(self, size, token, foreign_key, foreign_entity_name, options
         insert(offset, row[field_name])
       end
 
-      offset = cjson.encode(offset)
+      offset = cjson_safe.encode(offset)
       offset = encode_base64(offset, true)
 
       return rows, nil, offset

kong/db/strategies/postgres/tags.lua

@@ -1,4 +1,3 @@
-local cjson         = require "cjson"
 local cjson_safe    = require "cjson.safe"
 
 
@@ -118,7 +117,7 @@ local function page(self, size, token, options, tag)
         last_ordinality
       }
 
-      offset = cjson.encode(offset)
+      offset = cjson_safe.encode(offset)
       offset = encode_base64(offset, true)
 
       return rows, nil, offset

kong/globalpatches.lua

@@ -1,3 +1,5 @@
+local constants = require "kong.constants"
+
 local ran_before
 
 
@@ -15,15 +17,16 @@ return function(options)
   local meta = require "kong.meta"
 
 
-  local cjson = require("cjson.safe")
-  cjson.encode_sparse_array(nil, nil, 2^15)
+  local cjson_safe = require("cjson.safe")
+  cjson_safe.encode_sparse_array(nil, nil, 2^15)
+  cjson_safe.encode_number_precision(constants.CJSON_MAX_PRECISION)
 
   local pb = require "pb"
 
   -- let pb decode arrays to table cjson.empty_array_mt metatable
   -- so empty arrays are encoded as `[]` instead of `nil` or `{}` by cjson.
   pb.option("decode_default_array")
-  pb.defaults("*array", cjson.empty_array_mt)
+  pb.defaults("*array", cjson_safe.empty_array_mt)
 
   if options.cli then
     -- disable the _G write guard alert log introduced in OpenResty 1.15.8.1

kong/pdk/request.lua

@@ -6,7 +6,7 @@
 -- @module kong.request
 
 
-local cjson = require "cjson.safe".new()
+local cjson = require "kong.tools.cjson"
 local multipart = require "multipart"
 local phase_checker = require "kong.pdk.private.phases"
 local normalize = require("kong.tools.uri").normalize
@@ -44,8 +44,6 @@ local decode_args = ngx.decode_args
 local PHASES = phase_checker.phases
 
 
-cjson.decode_array_with_array_mt(true)
-
 
 local function new(self)
   local _REQUEST = {}
@@ -832,7 +830,7 @@ local function new(self)
         return nil, err, CONTENT_TYPE_JSON
       end
 
-      local json = cjson.decode(body)
+      local json = cjson.decode_with_array_mt(body)
       if type(json) ~= "table" then
         return nil, "invalid json body", CONTENT_TYPE_JSON
       end

kong/pdk/service/response.lua

@@ -3,7 +3,7 @@
 -- @module kong.service.response
 
 
-local cjson = require "cjson.safe".new()
+local cjson = require "kong.tools.cjson"
 local multipart = require "multipart"
 local phase_checker = require "kong.pdk.private.phases"
 local string_tools = require "kong.tools.string"
@@ -23,8 +23,6 @@ local setmetatable = setmetatable
 local check_phase = phase_checker.check
 
 
-cjson.decode_array_with_array_mt(true)
-
 
 local replace_dashes       = string_tools.replace_dashes
 local replace_dashes_lower = string_tools.replace_dashes_lower
@@ -356,7 +354,7 @@ local function new(pdk, major_version)
 
     elseif find(content_type_lower, CONTENT_TYPE_JSON, 1, true) == 1 then
       local body = response.get_raw_body()
-      local json = cjson.decode(body)
+      local json = cjson.decode_with_array_mt(body)
       if type(json) ~= "table" then
         return nil, "invalid json body", CONTENT_TYPE_JSON
       end

kong/tools/cjson.lua

@@ -0,0 +1,21 @@
+local cjson = require "cjson.safe".new()
+local constants = require "kong.constants"
+
+cjson.decode_array_with_array_mt(true)
+cjson.encode_sparse_array(nil, nil, 2^15)
+cjson.encode_number_precision(constants.CJSON_MAX_PRECISION)
+
+local _M = {}
+
+
+function _M.encode(json_text)
+  return cjson.encode(json_text)
+end
+
+function _M.decode_with_array_mt(json_text)
+  return cjson.decode(json_text)
+end
+
+_M.array_mt = cjson.array_mt
+
+return _M

spec/02-integration/04-admin_api/25-max_safe_integer_spec.lua

@@ -0,0 +1,110 @@
+local helpers  = require "spec.helpers"
+
+local LMDB_MAP_SIZE = "10m"
+
+for _, strategy in helpers.each_strategy() do
+  if strategy ~= "off" then
+    describe("Admin API #" .. strategy, function()
+      local bp
+      local client, route
+
+      lazy_setup(function()
+        bp = helpers.get_db_utils(strategy, {
+          "routes",
+          "services",
+        })
+
+        route = bp.routes:insert({
+          paths = { "/route_with_max_safe_integer_priority"},
+          regex_priority = 9007199254740992,
+        })
+
+        assert(helpers.start_kong({
+          database = strategy,
+        }))
+      end)
+
+      lazy_teardown(function()
+        helpers.stop_kong(nil, true)
+      end)
+
+      before_each(function()
+        client = assert(helpers.admin_client())
+      end)
+
+      after_each(function()
+        if client then
+          client:close()
+        end
+      end)
+
+      it("the maximum safe integer can be accurately represented as a decimal number", function()
+        local res = assert(client:send {
+          method = "GET",
+          path   = "/routes/" .. route.id
+        })
+        assert.res_status(200, res)
+        assert.match_re(res:read_body(), "9007199254740992")
+      end)
+    end)
+  end
+
+  if strategy == "off" then
+    describe("Admin API #off", function()
+      local client
+
+      lazy_setup(function()
+        assert(helpers.start_kong({
+          database = "off",
+          lmdb_map_size = LMDB_MAP_SIZE,
+          stream_listen = "127.0.0.1:9011",
+          nginx_conf = "spec/fixtures/custom_nginx.template",
+        }))
+      end)
+
+      lazy_teardown(function()
+        helpers.stop_kong(nil, true)
+      end)
+
+      before_each(function()
+        client = assert(helpers.admin_client())
+      end)
+
+      after_each(function()
+        if client then
+          client:close()
+        end
+      end)
+
+      it("the maximum safe integer can be accurately represented as a decimal number", function()
+        local res = assert(client:send {
+          method = "POST",
+          path = "/config",
+          body = {
+            config = [[
+            _format_version: "1.1"
+            services:
+            - name: my-service
+              id: 0855b320-0dd2-547d-891d-601e9b38647f
+              url: https://localhost
+              routes:
+              - name: my-route
+                id: 481a9539-f49c-51b6-b2e2-fe99ee68866c
+                paths:
+                - /
+                regex_priority: 9007199254740992
+            ]],
+          },
+          headers = {
+            ["Content-Type"] = "application/json"
+          }
+        })
+
+        assert.response(res).has.status(201)
+        local res = client:get("/routes/481a9539-f49c-51b6-b2e2-fe99ee68866c")
+        assert.res_status(200, res)
+        assert.match_re(res:read_body(), "9007199254740992")
+      end)
+    end)
+  end
+end

t/01-pdk/08-response/11-exit.t

@@ -1155,3 +1155,28 @@ X-test: test
 manually setting Transfer-Encoding. Ignored.
 
 
+
+=== TEST 45: response.exit() json encoding of numbers with a precision of 16 decimals
+--- http_config eval: $t::Util::HttpConfig
+--- config
+    location = /t {
+        default_type 'text/test';
+        access_by_lua_block {
+            require("kong.globalpatches")()
+            local PDK = require "kong.pdk"
+            local pdk = PDK.new()
+
+            pdk.response.exit(200, { n = 9007199254740992 })
+        }
+    }
+--- request
+GET /t
+--- error_code: 200
+--- response_headers_like
+Content-Type: application/json; charset=utf-8
+--- response_body chop
+{"n":9007199254740992}
+--- no_error_log
+[error]
+
+