From: Anbang Wen <xofyarg@gmail.com>
Date: Wed, 18 Apr 2018 20:37:42 +0000 (-0700)
Subject: export a JSON decode function to lua
X-Git-Tag: v2.3.0~4^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=15ba9591a7973f82f27901030cb9f7ca9c31073d;p=thirdparty%2Fknot-resolver.git

export a JSON decode function to lua

Since there is already a bundled JSON library, expose it to lua for
modules to use.
---

diff --git a/daemon/engine.c b/daemon/engine.c
index 91390c452..7dc89d431 100644
--- a/daemon/engine.c
+++ b/daemon/engine.c
@@ -472,6 +472,26 @@ static int l_tojson(lua_State *L)
 	return 1;
 }
 
+static int l_fromjson(lua_State *L)
+{
+	if (lua_gettop(L) != 1 || !lua_isstring(L, 1)) {
+		lua_pushliteral(L, "a JSON string is required");
+		lua_error(L);
+	}
+
+	const char *json_str = lua_tostring(L, 1);
+	JsonNode *root_node = json_decode(json_str);
+
+	if (!root_node) {
+		lua_pushliteral(L, "invalid JSON string");
+		lua_error(L);
+	}
+	l_unpack_json(L, root_node);
+	json_delete(root_node);
+
+	return 1;
+}
+
 /** @internal Throw Lua error if expr is false */
 #define expr_checked(expr) \
 	if (!(expr)) { lua_pushboolean(L, false); lua_rawseti(L, -2, lua_rawlen(L, -2) + 1); continue; }
@@ -642,6 +662,8 @@ static int init_state(struct engine *engine)
 	lua_setglobal(engine->L, "libzscanner_SONAME");
 	lua_pushcfunction(engine->L, l_tojson);
 	lua_setglobal(engine->L, "tojson");
+	lua_pushcfunction(engine->L, l_fromjson);
+	lua_setglobal(engine->L, "fromjson");
 	lua_pushcfunction(engine->L, l_map);
 	lua_setglobal(engine->L, "map");
 	lua_pushlightuserdata(engine->L, engine);
diff --git a/tests/config/basic.test.lua b/tests/config/basic.test.lua
index b4d756285..1d0ea6b42 100644
--- a/tests/config/basic.test.lua
+++ b/tests/config/basic.test.lua
@@ -122,9 +122,32 @@ local function test_packet_functions()
 	is(#pkt:towire(), 12, 'recycle() clears the packet wireformat')
 end
 
+-- test JSON encode/decode functions
+local function test_json_functions()
+	for msg, obj in pairs({
+			['number'] = 0,
+			['string'] = 'ok',
+			['list'] = {1, 2, 3},
+			['map'] = {foo='bar'},
+			['nest structure'] = {foo='bar', baz={1,2,3}},
+	}) do
+		same(fromjson(tojson(obj)), obj, 'json test: ' .. msg)
+	end
+
+	for _, str in ipairs({
+			'{', '}',
+			'[', ']',
+			'x,',
+			'[1,2,3,]',
+	}) do
+		boom(fromjson, {'{'}, 'json test: invalid \'' .. str .. '\'')
+	end
+end
+
 return {
 	test_constants,
 	test_globals,
 	test_rrset_functions,
 	test_packet_functions,
+	test_json_functions,
 }