fix(json): ensure empty array is the same after decode then encode (#6383)

apisix/core/json.lua

@@ -14,7 +14,8 @@
 -- See the License for the specific language governing permissions and
 -- limitations under the License.
 --
-local json_encode = require("cjson.safe").encode
+local cjson = require("cjson.safe")
+local json_encode = cjson.encode
 local clear_tab = require("table.clear")
 local ngx = ngx
 local tostring = tostring
@@ -23,10 +24,11 @@ local pairs = pairs
 local cached_tab = {}
 
 
+cjson.decode_array_with_array_mt(true)
 local _M = {
     version = 0.1,
-    array_mt = require("cjson.safe").array_mt,
-    decode = require("cjson.safe").decode,
+    array_mt = cjson.array_mt,
+    decode = cjson.decode,
     -- This method produces the same encoded string when the input is not changed.
     -- Different calls with cjson.encode will produce different string because
     -- it doesn't maintain the object key order.

ci/pod/opa/data.json

@@ -20,6 +20,11 @@
                 "code": 40001,
                 "desc": "Give you a object reason"
             }
+        },
+        "elisa": {
+            "reason": {
+               "info": []
+            }
         }
     }
 }

t/admin/services.t

@@ -1068,7 +1068,7 @@ GET /t
             local t = require("lib.test_admin").test
             local code, body = t('/apisix/admin/services/1',
                 ngx.HTTP_PUT,
-                {},
+                '{}',
                 [[{
                     "node": {
                         "value": {"id":"1"}

t/core/json.t

@@ -20,6 +20,18 @@ repeat_each(2);
 no_long_string();
 no_root_location();
 
+add_block_preprocessor(sub {
+    my ($block) = @_;
+
+    if (!$block->request) {
+        $block->set_value("request", "GET /t");
+    }
+
+    if ((!defined $block->error_log) && (!defined $block->no_error_log)) {
+        $block->set_value("no_error_log", "[error]");
+    }
+});
+
 run_tests;
 
 __DATA__
@@ -37,13 +49,9 @@ __DATA__
             ngx.say("data: ", data.test)
         }
     }
---- request
-GET /t
 --- response_body
 encode: {"test":"test"}
 data: test
---- no_error_log
-[error]
 
 
 
@@ -61,8 +69,6 @@ data: test
             ngx.log(ngx.ERR, "data2 val: ", data2)
         }
     }
---- request
-GET /t
 --- response_body
 delay encode: true
 data1 type: table
@@ -82,12 +88,8 @@ data2 val: {"test":"test2"}
             ngx.say("encode: ", data)
         }
     }
---- request
-GET /t
 --- response_body_like eval
 qr/\{("test":"test","fun":"function: 0x[0-9a-f]+"|"fun":"function: 0x[0-9a-f]+","test":"test")}/
---- no_error_log
-[error]
 
 
 
@@ -103,12 +105,8 @@ qr/\{("test":"test","fun":"function: 0x[0-9a-f]+"|"fun":"function: 0x[0-9a-f]+",
             ngx.say("encode: ", json_data)
         }
     }
---- request
-GET /t
 --- response_body_like eval
 qr/encode: \{"test":"cdata\<char \*\[1\]>: 0x[0-9a-f]+"\}/
---- no_error_log
-[error]
 
 
 
@@ -126,9 +124,22 @@ qr/encode: \{"test":"cdata\<char \*\[1\]>: 0x[0-9a-f]+"\}/
             ngx.say("encode: ", json_data)
         }
     }
---- request
-GET /t
 --- response_body eval
 qr/\{"b":\{"a":\{"b":"table: 0x[\w]+"\}\}\}/
---- no_error_log
-[error]
+
+
+
+=== TEST 6: decode/encode empty array
+--- config
+    location /t {
+        content_by_lua_block {
+            local core = require("apisix.core")
+            local data = core.json.decode('{"arr":[]}')
+            ngx.say(core.json.encode(data))
+            local data = core.json.decode('{"obj":{}}')
+            ngx.say(core.json.encode(data))
+        }
+    }
+--- response_body
+{"arr":[]}
+{"obj":{}}

t/lib/test_admin.lua

@@ -168,6 +168,7 @@ function _M.test(uri, method, body, pattern, headers)
     end
 
     if type(body) == "table" then
+        -- {} will be encoded as '[]' whether decode_array_with_array_mt or not
         body = json.encode(body)
     end
 

t/node/service-empty.t

@@ -33,7 +33,7 @@ __DATA__
             local t = require("lib.test_admin").test
             local code, body = t('/apisix/admin/services/1',
                 ngx.HTTP_PUT,
-                {},
+                '{}',
                 [[{
                     "node": {
                         "value": {"id":"1"}

t/plugin/opa2.t

@@ -185,3 +185,42 @@ apikey: test-key
 --- error_code: 403
 --- response_body_unlike eval
 qr/\"service\"/ and qr/\"consumer\"/
+
+
+
+=== TEST 7: setup route
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                ngx.HTTP_PUT,
+                [[{
+                    "plugins": {
+                        "opa": {
+                            "host": "http://127.0.0.1:8181",
+                            "policy": "example"
+                        }
+                    },
+                    "upstream_id": "u1",
+                    "uri": "/hello"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- response_body
+passed
+
+
+
+=== TEST 8: hit route (with JSON empty array)
+--- request
+GET /hello?user=elisa
+--- error_code: 403
+--- response_body chomp
+{"info":[]}