【高级技巧】协议测试：协议变更的自动化回归封装

local samples = {}
local function recordSample(kind, req, resp)
    samples[#samples + 1] = { kind = kind, req = req,
        resp = resp, volatile = { ts = true } }
end
local function compareResp(old, new)
    for k, v in pairs(old) do
        if not volatile[k] and new[k] ~= v then
            return false, "字段 " .. k .. " 由 " .. tostring(v) ..
                " 变为 " .. tostring(new[k])
        end
    end
    for k in pairs(new) do
        if old[k] == nil and not volatile[k] then
            return false, "新增字段 " .. k
        end
    end
    return true
end
local function runRegression()
    local failed = {}
    for i, s in ipairs(samples) do
        local newResp = replayRequest(s.kind, s.req)
        local ok, why = compareResp(s.resp, newResp)
        if not ok then
            failed[#failed + 1] = i .. ": " .. why
        end
    end
    return failed
end

local failed = runRegression()
if #failed > 0 then
    for _, f in ipairs(failed) do
        print("回归失败：" .. f)
    end
end