Refactor stringify, add tests for it, and use it in some exports

spec/System/TestUtils_spec.lua

@@ -0,0 +1,111 @@
+describe("Utils.stringify", function()
+	local utils = require("Modules/Utils")
+
+	-- Parses stringify output back into a Lua value
+	local function serializeAndLoad(value, allowNewlines)
+		local str = utils.stringify(value, allowNewlines)
+		local chunk, err = loadstring("return "..str)
+		assert.is_truthy(chunk)
+		return chunk(), str
+	end
+
+	describe("scalars", function()
+		it("stringifies strings with quotes", function()
+			assert.equal('"hello"', utils.stringify("hello"))
+		end)
+
+		it("strips newlines from strings by default", function()
+			assert.equal('"a b"', utils.stringify("a\nb"))
+		end)
+
+		it("preserves newlines as long strings when allowed", function()
+			assert.equal("[[a\nb]]", utils.stringify("a\nb", true))
+		end)
+
+		it("does not use long string form for newline-free strings", function()
+			assert.equal('"ab"', utils.stringify("ab", true))
+		end)
+
+		it("stringifies numbers", function()
+			assert.equal("42", utils.stringify(42))
+			assert.equal("-3.5", utils.stringify(-3.5))
+		end)
+
+		it("stringifies booleans", function()
+			assert.equal("true", utils.stringify(true))
+			assert.equal("false", utils.stringify(false))
+		end)
+
+		it("stringifies nil", function()
+			assert.equal("nil", utils.stringify(nil))
+		end)
+
+		-- supposedly these are valid table keys, but like come on
+		it("errors on disallowed types", function()
+			assert.has_error(function() utils.stringify(function() end) end)
+			assert.has_error(function() utils.stringify({[ function() end ] = "hello"}) end)
+		end)
+	end)
+
+	describe("tables", function()
+		it("serializes and loads an empty table", function()
+			local out = serializeAndLoad({})
+			assert.same({}, out)
+		end)
+
+		it("serializes and loads an array using array syntax", function()
+			local input = { 1, 2, 3 }
+			local out, str = serializeAndLoad(input)
+			assert.same(input, out)
+			-- array entries should not include explicit keys
+			assert.is_nil(str:find("%[1%]"))
+		end)
+
+		it("serializes and loads a string-keyed map", function()
+			local input = { foo = "bar", baz = 1 }
+			local out = serializeAndLoad(input)
+			assert.same(input, out)
+		end)
+
+		it("serializes and loads nested tables (no mixed array/map levels)", function()
+			local input = { a = { b = { c = { deep = true, value = 3 } } }, list = { "x", "y" } }
+			local out = serializeAndLoad(input)
+			assert.same(input, out)
+		end)
+
+		it("sorts map keys deterministically", function()
+			local str = utils.stringify({ c = 1, a = 1, b = 1 })
+			local posA = str:find('%["a"%]')
+			local posB = str:find('%["b"%]')
+			local posC = str:find('%["c"%]')
+			assert.is_truthy(posA < posB and posB < posC)
+		end)
+
+		it("serializes and loads numeric (non-sequential) keys", function()
+			local input = { [5] = "five", [10] = "ten" }
+			local out = serializeAndLoad(input)
+			assert.same(input, out)
+		end)
+
+		it("serializes and loads multiline string values when allowed", function()
+			local input = { text = "line1\nline2" }
+			local out = serializeAndLoad(input, true)
+			assert.same(input, out)
+		end)
+
+		it("serializes and loads mixed tables", function()
+			local input = {"one", "two", six = 7, 3, 4, five = "six"}
+			local str = utils.stringify(input, false, 1)
+			assert.equal([[{
+	"one",
+	"two",
+	3,
+	4,
+	["five"] = "six",
+	["six"] = 7,
+}]], str)
+			local out = serializeAndLoad(input)
+			assert.same(input, out)
+		end)
+	end)
+end)

src/Classes/TradeQueryGenerator.lua

@@ -10,6 +10,7 @@ local m_max = math.max
 local s_format = string.format
 local t_insert = table.insert
 local tradeHelpers = LoadModule("Classes/TradeHelpers")
+local utils = LoadModule("Modules/Utils")
 
 -- string are an any type while tables require all fields to be matched with type and subType require both to be matched exactly. [1] type, [2] subType, subType is optional and must be nil if not present.
 local tradeCategoryNames = {
@@ -395,11 +396,6 @@ function TradeQueryGeneratorClass:InitMods()
 		error("Error received from api/trade2/data/stats: "..body.error.message)
 	end
 
-	local f = io.open("./Data/TradeSiteStats.lua", "w")
-	if not f then
-		error("Could not open file for writing trade stat data")
-	end
-
 	for catIdx, _ in ipairs(body.result) do
 		table.sort(body.result[catIdx].entries, function(a, b)
 			if a.text == b.text then
@@ -409,14 +405,8 @@ function TradeQueryGeneratorClass:InitMods()
 		end)
 	end
 
-	local template = [[-- This file is automatically downloaded, do not edit!
--- Trade site stat data (c) Grinding Gear Games
--- https://www.pathofexile.com/api/trade2/data/stats
--- spell-checker: disable
-return %s
--- spell-checker: enable]]
-	f:write(s_format(template, stringify(body.result)))
-	f:close()
+	local description = "This file contains the trade site data from https://www.pathofexile.com/api/trade2/data/stats"
+	utils.saveTableToFile("./Data/TradeSiteStats.lua", body.result, description)
 
 	self.modData = {
 		["Explicit"] = { },
@@ -636,19 +626,12 @@ return %s
 		end
 	end
 
-	local queryModsFile = io.open(queryModFilePath, 'w')
-	queryModsFile:write([[-- This file is automatically generated, do not edit!
--- Stat data (c) Grinding Gear Games
-
--- This file contains categories of stats, mapped from trade hash to details
--- relevant for generating search weights Note that the trade site requires a
--- prefix of e.g. explicit.stat_{hash}. See
--- https://www.pathofexile.com/api/trade2/data/stats for a list of all trade
--- site stats.
-
-]])
-	queryModsFile:write("return " .. stringify(self.modData))
-	queryModsFile:close()
+	local qmDescription = [[This file contains categories of stats, mapped from trade hash to details
+relevant for generating search weights Note that the trade site requires a
+prefix of e.g. explicit.stat_{hash}. See
+TradeSiteStats.lua for a list of all trade
+site stats.]]
+	utils.saveTableToFile(queryModFilePath, self.modData, qmDescription)
 end
 
 function TradeQueryGeneratorClass:GenerateModWeights(modsToTest)

src/Classes/TradeQueryRequests.lua

@@ -5,6 +5,7 @@
 --
 
 local dkjson = require "dkjson"
+local utils = LoadModule("Modules/Utils")
 
 ---@class TradeQueryRequests
 local TradeQueryRequestsClass = newClass("TradeQueryRequests", function(self, rateLimiter)
@@ -219,7 +220,7 @@ function TradeQueryRequestsClass:PerformSearch(realm, league, query, callback)
 				if response.error then
 					if not (response.error.code and response.error.message) then
 						errMsg = "Encountered unknown error, check console for details."
-						ConPrintf("Unknown error: %s", stringify(response.error))
+						ConPrintf("Unknown error: %s", utils.stringify(response.error))
 						callback(response, errMsg)
 					end
 					if response.error.message:find("Logging in will increase this limit") then