Rework class syntax to make the code base legible for language servers

Author: vaisest

.gitignore

@@ -18,6 +18,7 @@ luajit/
 spec/test_results.log
 spec/test_generation.log
 src/luacov.stats.out
+runtime/lua/debugger.lua
 
 # Release
 manifest-updated.xml
@@ -38,4 +39,8 @@ src/Data/TimelessJewelData/*.bin
 runtime/imgui.ini
 runtime/SimpleGraphic/SimpleGraphic.log
 
-src/poe_api_response.json
+src/poe_api_response.json
+runtime/SimpleGraphic/Screenshots
+
+.emmyrc.json
+.luarc.json

CONTRIBUTING.md

@@ -136,6 +136,14 @@ It is recommended to use it over the built-in Lua plugins.
 Please note that EmmyLua is not available for other editors based on Visual Studio Code,
 such as [VSCodium](https://vscodium.com) or [Eclipse Theia](https://theia-ide.org) but can be built from source if needed.
 
+Another alternative on VSCode is to use [sumneko's Lua language server](https://marketplace.visualstudio.com/items?itemName=sumneko.lua) along with [actboy168's debugger](https://marketplace.visualstudio.com/items?itemName=actboy168.lua-debug). These can potentially offer more features than EmmyLua, such as conditional breakpoints.
+
+## Runtime environment
+
+It is recommended that you configure your IDE to include `src/_SimpleGraphic.def.lua` somehow. Path of Building runs inside a special Lua environment via SimpleGraphic which implements a small API. These are not defined inside the project, which means that the aforementioned meta/hint file is required for the IDE to know which functions exist. As the file is not included in code, it must be explicitly mentioned as a library in whichever language server you are using, or otherwise it will not be read.
+
+This file is normally not executed, but does contain basic implementations for parts of the API, which allows many parts of PoB to work without running inside SimpleGraphic. If you wish to test individual changes, it might be possible to do so through a script using Luajit directly. To do so, see HeadlessWrapper.lua for an example. It should be noted that some parts of the API (such as subscripts) are not implemented, which means some parts of PoB are unusable.
+
 ### Visual Studio Code
 
 1. Create a new <kbd>Debug Configuration</kbd> of type <kbd>EmmyLua New Debug</kbd>
@@ -168,20 +176,54 @@ such as [VSCodium](https://vscodium.com) or [Eclipse Theia](https://theia-ide.or
 1. In VSCode click <kbd>Start Debugging</kbd> (the green icon) or press <kbd>F5</kbd>
 1. The debugger should connect
 
+You might also want to use actboy168 debugger. This is possible by using for example the following launch.json configuration:
+
+```json
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "🍄attach",
+            "type": "lua",
+            "request": "attach",
+            "stopOnEntry": false,
+            "address": "127.0.0.1:12306",
+            "luaVersion": "luajit",
+        },
+
+    ]
+}
+```
+
+Then, similarly to the EmmyLua example:
+
+1. Find the sub-folder that looks like `actboy168.lua-debug-x.y.z-win32-x64` in `%USERPROFILE%/.vscode/extensions`. Navigate to it and find the `debugger.lua` script under the script folder. Copy this to `runtime/lua`.
+2. Copy-paste the following code snippet into `launch:OnInit()`:
+  ```lua
+  local debugger = require("debugger"):start("127.0.0.1:12306")
+  -- debugger:event("wait")  -- Uncomment this line if you want PoB to wait until the debugger is attached.
+  ```
+
 
 #### Excluding directories from EmmyLua
 
 Depending on the amount of system ram you have available and the amount that gets assigned to the jvm running the emmylua language server you might run into issues when trying to debug Path of building.
-Files in `/Data` `/Export` and `/TreeData` can be massive and cause the EmmyLua language server to use a significant amount of memory. Sometimes causing the language server to crash. To avoid this and speed up initialization consider adding an `.emmyrc.json` file to the `.vscode` folder in the root of the Path of building folder with the following content:
+Files in `/Data` `/Export` and `/TreeData` can be massive and cause the EmmyLua language server to use a significant amount of memory. Sometimes causing the language server to crash. To avoid this and speed up initialization consider adding an `.emmyrc.json` to the root of the Path of building folder with the following content:
 
 ```json
 {
     "$schema": "https://raw.githubusercontent.com/EmmyLuaLs/emmylua-analyzer-rust/refs/heads/main/crates/emmylua_code_analysis/resources/schema.json",
     "runtime": {
-        "version": "LuaJIT"
+        "version": "LuaJIT",
+        // this is not technically correct as LoadModule behaviour can
+        // differ from require, but it is useful for now
+        "requireLikeFunction": ["LoadModule"],
     },
     "workspace": {
         "ignoreGlobs": [
+            "**/*_spec.lua",
+            "spec/**/*.lua",
+            "runtime/lua/sha1/lua53_ops.lua",
             "**/src/Data/**/*.lua",
             "**/src/TreeData/**/*.lua",
             "**/src/Modules/ModParser.lua"
@@ -190,6 +232,46 @@ Files in `/Data` `/Export` and `/TreeData` can be massive and cause the EmmyLua
 }
 ```
 
+This file can be customised according to what you want. It is a good idea to ignore test files as these tend to add things to the global namespace, which will look confusing, and they are designed to be run by Busted. `lua53_ops.lua` produces errors and doesn't actually get imported when using LuaJIT. It can be useful to keep the data and mod parser files, but generally this will increase the time the LSP takes to index the project on startup.
+
+### Excluding directories from Sumneko's language server
+
+If you prefer to not use EmmyLua, the following configuration works well for Sumneko's VS Code extension:
+
+```json
+{
+    "Lua.workspace.ignoreDir": [
+        ".vscode",
+        // these files add things to global that aren't there in normal
+        // operation
+        "spec/*",
+        "src/Export/*",
+        "src/HeadlessWrapper.lua",
+
+        // this has lua 5.3 code which produces errors, but doesn't actually run
+        "src/runtime/lua/sha1/*",
+
+        // avoid overriding the below library setting
+        "src/_SimpleGraphic.def.lua",
+    ],
+    "Lua.diagnostics.disable": ["inject-field"],
+    // disables diagnostics even when you open one of the above
+    "Lua.diagnostics.ignoredFiles": "Disable",
+    "Lua.runtime.version": "LuaJIT",
+    "Lua.workspace.preloadFileSize": 1000,
+    // this is not technically correct as LoadModule behaviour can
+    // differ from require, but it is useful for now
+    "Lua.runtime.special": {
+        "LoadModule": "require"
+    },
+    "Lua.workspace.library": [
+        "src/_SimpleGraphic.def.lua"
+    ],
+}
+```
+
+The extension will automatically skip large files from being preloaded (controlled by `Lua.workspace.preloadFileSize`), so they don't have to be excluded. The configuration file can be found by pressing Ctrl-Shift-P and selecting `Preferences: Open Workspace Settings (JSON)`. If you wish to check test files, you can remove the "ignoredFiles" option and install the busted, LuaFileSystem, and luassert LuaLS addons through `Lua: Open Addon Manager`.
+
 ### PyCharm Community / IntelliJ Idea Community
 
 1. Create a new "Debug Configuration" of type "Emmy Debugger(NEW)".
@@ -223,6 +305,13 @@ More tests can be added to this folder to test specific functionality, or new te
 
 Please try to include tests for your new features in your pull request. Additionally, if your pr breaks a test that should be passing please update it accordingly.
 
+It can also be a good idea to install `busted` locally as it tends to be faster to execute:
+
+1. Install Luajit (due to PoB accessing the jit library, it non-Luajit versions might not work)
+2. Install [Luarocks](https://luarocks.org/) (for example, through Scoop or your Linux package manager)
+3. Run `luarocks install busted`
+4. Run `busted --lua=luajit` to run the tests. You can also use e.g. `-p TestUtils_spec.lua` to run a specific file.
+
 ### Debugging tests
 When running tests with a docker container it is possible to use EmmyLua for debugging. Paste in the following right under `function launch:OnInit()` in `./src/Launch.lua`:
 ```lua

spec/System/TestCommon_spec.lua

@@ -0,0 +1,70 @@
+describe("Common", function()
+	describe("Class creation and use", function()
+		it("produces error when parent constructors are not called", function()
+			local ParentClass = newClass("ConstructorTestParentClass")
+			function ParentClass:ConstructorTestParentClass()
+				return self
+			end
+			local ChildClass = newClass("ConstructorTestProblemChildClass", "ConstructorTestParentClass")
+			function ChildClass:ConstructorTestProblemChild()
+				-- Intentionally does not call self:ConstructorTestParentClass()
+				return self
+			end
+			common.classes.ConstructorTestParent = ParentClass
+			common.classes.ConstructorTestProblemChild = ChildClass
+
+			assert.has_error(function()
+				new("ConstructorTestProblemChild"):ConstructorTestProblemChild()
+			end, "Parent class 'ConstructorTestParentClass' of class 'ConstructorTestProblemChild' must be initialised")
+			common.classes.ConstructorTestParent = nil
+			common.classes.ConstructorTestProblemChild = nil
+		end)
+		it("produces an error if additional arguments are passed", function()
+			local StupidClass = newClass("NewAbuse")
+			function StupidClass:NewAbuse(someParam)
+				return self
+			end
+
+			common.classes.NewAbuse = StupidClass
+
+			assert.has_no.errors(function()
+				local newObj = new("NewAbuse"):NewAbuse("fish")
+			end)
+			assert.has_error(function()
+				local newObj = new("NewAbuse", "look I'm using the old syntax")
+			end)
+		end)
+		it("produces an error if it calls a parent class without giving it self", function()
+			local ParentClass = newClass("ConstructorTestParentClass")
+			function ParentClass:ConstructorTestParentClass()
+				return self
+			end
+
+			local ChildClass = newClass("ConstructorTestProblemChildClass", "ConstructorTestParentClass")
+			function ChildClass:ConstructorTestProblemChild()
+				self.ConstructorTestParentClass()
+				return self
+			end
+
+			common.classes.ConstructorTestParent = ParentClass
+			common.classes.ConstructorTestProblemChild = ChildClass
+
+			assert.has_error(function()
+				new("ConstructorTestProblemChild"):ConstructorTestProblemChild()
+			end)
+			common.classes.ConstructorTestParent = nil
+			common.classes.ConstructorTestProblemChild = nil
+		end)
+		it("produces an error if its constructor doesn't return the object", function()
+			local StupidClass = newClass("StupidClass")
+			function StupidClass:StupidClass()
+			end
+
+			common.classes.StupidClass = StupidClass
+
+			assert.has_error(function()
+				new("StupidClass"):StupidClass()
+			end, "Class StupidClass constructor did not return a value")
+		end)
+	end)
+end)

spec/System/TestCompareBuySimilar_spec.lua

@@ -4,7 +4,7 @@ describe("Buy similar mod stat matching", function()
 
 	describe("addModEntries mod matching", function()
 		it("matches impossible escape mods as options", function()
-			local fromNothing = new("Item", [[
+			local fromNothing = new("Item"):Item([[
 Impossible Escape
 Viridian Jewel
 LevelReq: 0
@@ -32,7 +32,7 @@ Corrupted]])
 		end)
 
 		it("matches thread of hope radius as an option", function()
-			local thread = new("Item", [[
+			local thread = new("Item"):Item([[
 Rarity: UNIQUE
 Thread of Hope
 Crimson Jewel
@@ -52,7 +52,7 @@ Passage]])
 		end)
 
 		it("combines mods that are the same stat", function()
-			local lifeDiamond = new("Item", [[
+			local lifeDiamond = new("Item"):Item([[
 Test Subject
 Diamond
 Implicits: 0
@@ -67,7 +67,7 @@ Implicits: 0
 			assert.equal("+50 to Maximum Life", StripEscapes(entries[1].formattedLines[2]))
 			assert.equal(150, entries[1].value)
 
-			local lifelessDiamond = new("Item", [[
+			local lifelessDiamond = new("Item"):Item([[
 Test Subject
 Diamond
 Implicits: 0
@@ -82,7 +82,7 @@ Implicits: 0
 		end)
 
 		it("is not case-sensitive", function ()
-			local funnyItem = new("Item", [[
+			local funnyItem = new("Item"):Item([[
 Test Subject
 Diamond
 Implicits: 1
@@ -93,7 +93,7 @@ Implicits: 1
 		end)
 
 		it("does not combine implicit and explicit mods", function()
-			local lifelessDiamond = new("Item", [[
+			local lifelessDiamond = new("Item"):Item([[
 Test Subject
 Diamond
 Implicits: 1
@@ -140,7 +140,7 @@ Implicits: 1
 		end)
 
 		local function openPopup(item, slotName)
-			item = item or new("Item", "Rarity: Rare\nTest Ring\nRuby Ring\nImplicits: 0\n+50 to maximum Life")
+			item = item or new("Item"):Item("Rarity: Rare\nTest Ring\nRuby Ring\nImplicits: 0\n+50 to maximum Life")
 			bs.openPopup(item, slotName or "Ring", build)
 			local controls = main.popups[1].controls
 			_G.Copy = function(url) copiedUrl = url end
@@ -194,7 +194,7 @@ Implicits: 1
 		end)
 
 		it("encodes option values in the generated query", function()
-			local item = new("Item", [[
+			local item = new("Item"):Item([[
 Rarity: UNIQUE
 Impossible Escape
 Viridian Jewel
@@ -214,7 +214,7 @@ Corrupted]])
 		end)
 
 		it("inverts reduced stat bounds in the generated query", function()
-			local item = new("Item", [[
+			local item = new("Item"):Item([[
 Rarity: Rare
 Test Ring
 Ruby Ring
@@ -230,7 +230,7 @@ Implicits: 0
 		end)
 
 		it("uses a count group for ambiguous trade stats", function()
-			local item = new("Item", [[
+			local item = new("Item"):Item([[
 Rarity: Rare
 Test Ring
 Ruby Ring

spec/System/TestImport_spec.lua

@@ -71,7 +71,7 @@ describe("TestImport", function()
 	end)
 
 	function importAndReimportWithOldJewel(shouldDelete)
-		local oldJewel = new("Item", [[Rarity: RARE
+		local oldJewel = new("Item"):Item([[Rarity: RARE
 TEST JEWEL
 Crimson Jewel
 Crafted: true

spec/System/TestItemDBControl_spec.lua

@@ -33,7 +33,7 @@ describe("ItemDBControl", function()
 				return item ~= invalidItem
 			end,
 		}
-		local control = new("ItemDBControl", nil, { 0, 0, 100, 100 }, itemsTab, {
+		local control = new("ItemDBControl"):ItemDBControl(nil, { 0, 0, 100, 100 }, itemsTab, {
 			list = { invalidItem, betterItem, worseItem },
 		}, "RARE")
 		control.sortDetail = {

spec/System/TestItemMods_spec.lua

@@ -614,12 +614,12 @@ describe("TetsItemMods", function()
 	end)
 
 	it("shows a fallback tooltip when an item's base is no longer supported", function()
-		local item = new("Item", [[
+		local item = new("Item"):Item([[
 			Rarity: Unique
 			Legacy Item
 			Removed Base
 		]])
-		local tooltip = new("Tooltip")
+		local tooltip = new("Tooltip"):Tooltip()
 
 		assert.has_no.errors(function()
 			build.itemsTab:AddItemTooltip(tooltip, item)