From a8740bf0ee31d8baeca4b9bcb4c410e0c6cefac2 Mon Sep 17 00:00:00 2001
From: ms2008 <ms2008vip@gmail.com>
Date: Thu, 28 Dec 2023 23:04:58 +0800
Subject: [PATCH] feat(cjson): ensure `cjson.new` encode number with a
 precision of 16 decimals

---
 kong/db/strategies/postgres/init.lua          |  2 -
 kong/globalpatches.lua                        | 21 +++++++
 kong/pdk/response.lua                         |  1 -
 kong/plugins/zipkin/reporter.lua              |  1 -
 .../05-proxy/34-max_safe_integer_spec.lua     | 60 +++++++++++++++++++
 t/01-pdk/08-response/11-exit.t                |  1 +
 6 files changed, 82 insertions(+), 4 deletions(-)
 create mode 100644 spec/02-integration/05-proxy/34-max_safe_integer_spec.lua

diff --git a/kong/db/strategies/postgres/init.lua b/kong/db/strategies/postgres/init.lua
index e76af557e293..8f8c70ff12bc 100644
--- a/kong/db/strategies/postgres/init.lua
+++ b/kong/db/strategies/postgres/init.lua
@@ -6,8 +6,6 @@ local utils         = require "kong.tools.utils"
 local new_tab       = require "table.new"
 local clear_tab     = require "table.clear"
 
-cjson.encode_number_precision(16)
-cjson_safe.encode_number_precision(16)
 
 local kong          = kong
 local ngx           = ngx
diff --git a/kong/globalpatches.lua b/kong/globalpatches.lua
index c3782f0c8a0f..876c8234603f 100644
--- a/kong/globalpatches.lua
+++ b/kong/globalpatches.lua
@@ -14,6 +14,27 @@ return function(options)
   options = options or {}
   local meta = require "kong.meta"
 
+  do -- make cjson encode numbers with a precision of up to 16 decimals
+    local cjson = require "cjson"
+    local cjson_safe = require "cjson.safe"
+    local native_cjson_new = cjson.new
+    local native_cjson_safe_new = cjson_safe.new
+
+    cjson.encode_number_precision(16)
+    cjson_safe.encode_number_precision(16)
+
+    cjson.new = function()
+      local json = native_cjson_new()
+      json.encode_number_precision(16)
+      return json
+    end
+
+    cjson_safe.new = function()
+      local json = native_cjson_safe_new()
+      json.encode_number_precision(16)
+      return json
+    end
+  end
 
   local cjson = require("cjson.safe")
   cjson.encode_sparse_array(nil, nil, 2^15)
diff --git a/kong/pdk/response.lua b/kong/pdk/response.lua
index e196067cd311..37a0c67d11f4 100644
--- a/kong/pdk/response.lua
+++ b/kong/pdk/response.lua
@@ -20,7 +20,6 @@ local utils = require "kong.tools.utils"
 local request_id = require "kong.tracing.request_id"
 local constants = require "kong.constants"
 
-cjson.encode_number_precision(16)
 
 local ngx = ngx
 local arg = ngx.arg
diff --git a/kong/plugins/zipkin/reporter.lua b/kong/plugins/zipkin/reporter.lua
index 73c1111a81de..d01c3d605bc6 100644
--- a/kong/plugins/zipkin/reporter.lua
+++ b/kong/plugins/zipkin/reporter.lua
@@ -3,7 +3,6 @@ local to_hex = require "resty.string".to_hex
 local cjson = require "cjson".new()
 local Queue = require "kong.tools.queue"
 
-cjson.encode_number_precision(16)
 
 local zipkin_reporter_methods = {}
 local zipkin_reporter_mt = {
diff --git a/spec/02-integration/05-proxy/34-max_safe_integer_spec.lua b/spec/02-integration/05-proxy/34-max_safe_integer_spec.lua
new file mode 100644
index 000000000000..ed216c8bfc5b
--- /dev/null
+++ b/spec/02-integration/05-proxy/34-max_safe_integer_spec.lua
@@ -0,0 +1,60 @@
+local helpers = require "spec.helpers"
+
+for _, strategy in helpers.each_strategy() do
+  describe("cjson.new encode number with a precision of 16 decimals [#" .. strategy .. "]", function()
+    local proxy_client
+
+    lazy_setup(function()
+      local bp = helpers.get_db_utils(strategy, {
+        "routes",
+        "services",
+        "plugins",
+      }, { "pre-function" })
+
+      local route = bp.routes:insert({
+        paths = { "/route_with_max_safe_integer_priority"},
+      })
+
+      bp.plugins:insert {
+        route = { id = route.id },
+        name = "pre-function",
+        config = {
+          access = {
+            [[
+              local cjson = require("cjson").new()
+              ngx.say(cjson.encode({ n = 9007199254740992 }))
+            ]]
+          },
+        }
+      }
+
+      assert(helpers.start_kong({
+        database = strategy,
+        untrusted_lua = "on",
+        plugins = "bundled",
+        nginx_conf = "spec/fixtures/custom_nginx.template",
+        nginx_worker_processes = 1
+      }))
+
+      proxy_client = helpers.proxy_client()
+    end)
+
+    lazy_teardown(function()
+      if proxy_client then
+        proxy_client:close()
+      end
+
+      helpers.stop_kong()
+    end)
+
+    it("the maximum safe integer can be accurately represented as a decimal number", function()
+      local res = assert(proxy_client:send {
+        method = "GET",
+        path   = "/route_with_max_safe_integer_priority"
+      })
+
+      assert.res_status(200, res)
+      assert.match_re(res:read_body(), "9007199254740992")
+    end)
+  end)
+end
diff --git a/t/01-pdk/08-response/11-exit.t b/t/01-pdk/08-response/11-exit.t
index 8048b91cdbe7..4a6f7a624c92 100644
--- a/t/01-pdk/08-response/11-exit.t
+++ b/t/01-pdk/08-response/11-exit.t
@@ -1162,6 +1162,7 @@ manually setting Transfer-Encoding. Ignored.
     location = /t {
         default_type 'text/test';
         access_by_lua_block {
+            require("kong.globalpatches")()
             local PDK = require "kong.pdk"
             local pdk = PDK.new()