feature: Add option to skip invalid value types.

Co-authored-by: Jesper Lundgren <jesperlundgren@exosite.com>

2 files changed, 45 insertions, 14 deletions

diff --git a/lua-cjson-2.1.0.10-1.rockspec b/lua-cjson-2.1.0.11-1.rockspec
index 9ed4272..9ed4272 100644
--- a/lua-cjson-2.1.0.10-1.rockspec
+++ b/lua-cjson-2.1.0.11-1.rockspec
diff --git a/lua_cjson.c b/lua_cjson.c
index 94b0b46..42672de 100644
--- a/lua_cjson.c
+++ b/lua_cjson.c
@@ -82,6 +82,7 @@
 #define DEFAULT_ENCODE_EMPTY_TABLE_AS_OBJECT 1
 #define DEFAULT_DECODE_ARRAY_WITH_ARRAY_MT 0
 #define DEFAULT_ENCODE_ESCAPE_FORWARD_SLASH 1
+#define DEFAULT_ENCODE_SKIP_UNSUPPORTED_VALUE_TYPES 0
 
 #ifdef DISABLE_INVALID_NUMBERS
 #undef DEFAULT_DECODE_INVALID_NUMBERS
@@ -165,6 +166,7 @@ typedef struct {
     int decode_invalid_numbers;
     int decode_max_depth;
     int decode_array_with_array_mt;
+    int encode_skip_unsupported_value_types;
 } json_config_t;
 
 typedef struct {
@@ -356,6 +358,16 @@ static int json_cfg_decode_array_with_array_mt(lua_State *l)
     return 1;
 }
 
+/* Configure how to treat invalid types */
+static int json_cfg_encode_skip_unsupported_value_types(lua_State *l)
+{
+    json_config_t *cfg = json_arg_init(l, 1);
+
+    json_enum_option(l, 1, &cfg->encode_skip_unsupported_value_types, NULL, 1);
+
+    return 1;
+}
+
 /* Configures JSON encoding buffer persistence */
 static int json_cfg_encode_keep_buffer(lua_State *l)
 {
@@ -463,6 +475,7 @@ static void json_create_config(lua_State *l)
     cfg->encode_empty_table_as_object = DEFAULT_ENCODE_EMPTY_TABLE_AS_OBJECT;
     cfg->decode_array_with_array_mt = DEFAULT_DECODE_ARRAY_WITH_ARRAY_MT;
     cfg->encode_escape_forward_slash = DEFAULT_ENCODE_ESCAPE_FORWARD_SLASH;
+    cfg->encode_skip_unsupported_value_types = DEFAULT_ENCODE_SKIP_UNSUPPORTED_VALUE_TYPES;
 
 #if DEFAULT_ENCODE_KEEP_BUFFER > 0
     strbuf_init(&cfg->encode_buf, 0);
@@ -627,7 +640,7 @@ static void json_check_encode_depth(lua_State *l, json_config_t *cfg,
                current_depth);
 }
 
-static void json_append_data(lua_State *l, json_config_t *cfg,
+static int json_append_data(lua_State *l, json_config_t *cfg,
                              int current_depth, strbuf_t *json);
 
 /* json_append_array args:
@@ -637,19 +650,24 @@ static void json_append_data(lua_State *l, json_config_t *cfg,
 static void json_append_array(lua_State *l, json_config_t *cfg, int current_depth,
                               strbuf_t *json, int array_length)
 {
-    int comma, i;
+    int comma, i, json_pos, err;
 
     strbuf_append_char(json, '[');
 
     comma = 0;
     for (i = 1; i <= array_length; i++) {
-        if (comma)
+        json_pos = strbuf_length(json);
+        if (comma++ > 0)
             strbuf_append_char(json, ',');
-        else
-            comma = 1;
 
         lua_rawgeti(l, -1, i);
-        json_append_data(l, cfg, current_depth, json);
+        err = json_append_data(l, cfg, current_depth, json);
+        if (err) {
+            strbuf_set_length(json, json_pos);
+            if (comma == 1) {
+                comma = 0;
+            }
+        }
         lua_pop(l, 1);
     }
 
@@ -697,7 +715,7 @@ static void json_append_number(lua_State *l, json_config_t *cfg,
 static void json_append_object(lua_State *l, json_config_t *cfg,
                                int current_depth, strbuf_t *json)
 {
-    int comma, keytype;
+    int comma, keytype, json_pos, err;
 
     /* Object */
     strbuf_append_char(json, '{');
@@ -706,10 +724,9 @@ static void json_append_object(lua_State *l, json_config_t *cfg,
     /* table, startkey */
     comma = 0;
     while (lua_next(l, -2) != 0) {
-        if (comma)
+        json_pos = strbuf_length(json);
+        if (comma++ > 0)
             strbuf_append_char(json, ',');
-        else
-            comma = 1;
 
         /* table, key, value */
         keytype = lua_type(l, -2);
@@ -727,7 +744,14 @@ static void json_append_object(lua_State *l, json_config_t *cfg,
         }
 
         /* table, key, value */
-        json_append_data(l, cfg, current_depth, json);
+        err = json_append_data(l, cfg, current_depth, json);
+        if (err) {
+            strbuf_set_length(json, json_pos);
+            if (comma == 1) {
+                comma = 0;
+            }
+        }
+
         lua_pop(l, 1);
         /* table, key */
     }
@@ -735,8 +759,8 @@ static void json_append_object(lua_State *l, json_config_t *cfg,
     strbuf_append_char(json, '}');
 }
 
-/* Serialise Lua data into JSON string. */
-static void json_append_data(lua_State *l, json_config_t *cfg,
+/* Serialise Lua data into JSON string. Return 1 if error an error happened, else 0 */
+static int json_append_data(lua_State *l, json_config_t *cfg,
                              int current_depth, strbuf_t *json)
 {
     int len;
@@ -807,9 +831,15 @@ static void json_append_data(lua_State *l, json_config_t *cfg,
     default:
         /* Remaining types (LUA_TFUNCTION, LUA_TUSERDATA, LUA_TTHREAD,
          * and LUA_TLIGHTUSERDATA) cannot be serialised */
-        json_encode_exception(l, cfg, json, -1, "type not supported");
+        if (cfg->encode_skip_unsupported_value_types) {
+            return 1;
+        } else {
+            json_encode_exception(l, cfg, json, -1, "type not supported");
+        }
+
         /* never returns */
     }
+    return 0;
 }
 
 static int json_encode(lua_State *l)
@@ -1479,6 +1509,7 @@ static int lua_cjson_new(lua_State *l)
         { "encode_invalid_numbers", json_cfg_encode_invalid_numbers },
         { "decode_invalid_numbers", json_cfg_decode_invalid_numbers },
         { "encode_escape_forward_slash", json_cfg_encode_escape_forward_slash },
+        { "encode_skip_unsupported_value_types", json_cfg_encode_skip_unsupported_value_types },
         { "new", lua_cjson_new },
         { NULL, NULL }
     };