Software /
code /
prosody
File
tools/modtrace.lua @ 13196:eca44e058eed
util.human.io: Use tail call in test to get correct line numbers
This is probably not guaranteed to work and might vary with Lua version,
but it's good enough for me to get accurate line numbers out of Busted
that don't all point to the test() function.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 16 Jul 2023 18:42:58 +0200 (17 months ago) |
parent | 12590:5eaf77114fdb |
line wrap: on
line source
-- Trace module calls and method calls on created objects -- -- Very rough and for debugging purposes only. It makes many -- assumptions and there are many ways it could fail. -- -- Example use: -- -- local dbuffer = require "tools.modtrace".trace("util.dbuffer"); -- local t_pack = table.pack; local serialize = require "util.serialization".serialize; local unpack = table.unpack; local set = require "util.set"; local serialize_cfg = { preset = "oneline"; freeze = true; fatal = false; fallback = function (v) return "<"..tostring(v)..">" end; }; local function stringify_value(v) if type(v) == "string" and #v > 20 then return ("<string(%d)>"):format(#v); elseif type(v) == "function" then return tostring(v); end return serialize(v, serialize_cfg); end local function stringify_params(...) local n = select("#", ...); local r = {}; for i = 1, n do table.insert(r, stringify_value((select(i, ...)))); end return table.concat(r, ", "); end local function stringify_result(ret) local r = {}; for i = 1, ret.n do table.insert(r, stringify_value(ret[i])); end return table.concat(r, ", "); end local function stringify_call(method_name, ...) return ("%s(%s)"):format(method_name, stringify_params(...)); end local function wrap_method(original_obj, original_method, method_name) method_name = ("<%s>:%s"):format(getmetatable(original_obj).__name or "object", method_name); return function (new_obj_self, ...) local opts = new_obj_self._modtrace_opts; local f = opts.output or io.stderr; f:write(stringify_call(method_name, ...)); local ret = t_pack(original_method(original_obj, ...)); if ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end return unpack(ret, 1, ret.n); end; end local function wrap_function(original_function, function_name, opts) local f = opts.output or io.stderr; return function (...) f:write(stringify_call(function_name, ...)); local ret = t_pack(original_function(...)); if ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end return unpack(ret, 1, ret.n); end; end local function wrap_metamethod(name, method) if name == "__index" then return function (new_obj, k) local original_method; if type(method) == "table" then original_method = new_obj._modtrace_original_obj[k]; else original_method = method(new_obj._modtrace_original_obj, k); end if original_method == nil then return nil; end return wrap_method(new_obj._modtrace_original_obj, original_method, k); end; end return function (new_obj, ...) return method(new_obj._modtrace_original_obj, ...); end; end local function wrap_mt(original_mt) local new_mt = {}; for k, v in pairs(original_mt) do new_mt[k] = wrap_metamethod(k, v); end return new_mt; end local function wrap_obj(original_obj, opts) local new_mt = wrap_mt(getmetatable(original_obj)); return setmetatable({_modtrace_original_obj = original_obj, _modtrace_opts = opts}, new_mt); end local function wrap_new(original_new, function_name, opts) local f = opts.output or io.stderr; return function (...) f:write(stringify_call(function_name, ...)); local ret = t_pack(original_new(...)); local obj = ret[1]; if ret.n == 1 and type(ret[1]) == "table" then f:write(" = <", getmetatable(ret[1]).__name or "object", ">", "\n"); elseif ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end if obj then ret[1] = wrap_obj(obj, opts); end return unpack(ret, 1, ret.n); end; end local function trace(module, opts) if type(module) == "string" then module = require(module); end opts = opts or {}; local new_methods = set.new(opts.new_methods or {"new"}); local fake_module = setmetatable({}, { __index = function (_, k) if new_methods:contains(k) then return wrap_new(module[k], k, opts); else return wrap_function(module[k], k, opts); end end; }); return fake_module; end return { wrap = trace; trace = trace; }