René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[BUG] Adding a decorator to a class inside a namespace causes assignation to undefined `___exports`","articleBody":"# Description of the issue\nIn my current project, I created a namespace that is split across different files with the goal of containing declarations of classes that I later `declare` as global, and make actually global using a decorator, as described [in the docs](https://typescripttolua.github.io/docs/assigning-global-variables#registering-classes-with-a-decorator).\nHowever, using a decorator produces, in the compiled files, an assignation to `___exports` as the last instruction of the namespace definition.\n\n# Reproduction\nAside from the declaration and definition of a simple decorator (aptly named `Decorator`), I've made two files which both add a class to a namespace (`Repro`).\n**`WithoutDecorator.ts`**\n```ts\nnamespace Repro {\n    export class  WithoutDecorator {}\n}\n```\n\n**`WithDecorator.ts`**\n```ts\nnamespace Repro {\n  @Decorator\n  export class WithDecorator {}\n}\n```\n\nHere's the produced lua for those files:\n**`WithoutDecorator.lua`**\n```lua\nlocal ____lualib = require(\"lualib_bundle\")\nlocal __TS__Class = ____lualib.__TS__Class\nRepro = Repro or ({})\ndo\n    Repro.WithoutDecorator = __TS__Class()\n    local WithoutDecorator = Repro.WithoutDecorator\n    WithoutDecorator.name = \"WithoutDecorator\"\n    function WithoutDecorator.prototype.____constructor(self)\n    end\nend\n```\n\n**`WithDecorator.lua`**\n```lua\nlocal ____lualib = require(\"lualib_bundle\")\nlocal __TS__Class = ____lualib.__TS__Class\nlocal __TS__Decorate = ____lualib.__TS__Decorate\nRepro = Repro or ({})\ndo\n    Repro.WithDecorator = __TS__Class()\n    local WithDecorator = Repro.WithDecorator\n    WithDecorator.name = \"WithDecorator\"\n    function WithDecorator.prototype.____constructor(self)\n    end\n    WithDecorator = __TS__Decorate(WithDecorator, WithDecorator, {Decorator}, {kind = \"class\", name = \"WithDecorator\"})\n    ____exports.WithDecorator = WithDecorator -- [editor's note]: throws \"attempt to index global '____exports' (a nil value)\"\nend\n```\n\nTo test it for yourself, you can download this minimal reproduction repo: https://github.com/SirWrexes/tstl-decorator-bug.\nA `run.lua` file is provided to set the `package.path` to see results of compilation (inside `./lua/`) and require the two compiled sources.\n```sh\nnpm install\nnpx tstl\nlua ./run.lua\n```\n\n# Expected behaviour\nThis assignation should not happen. Behaviour should not be different with and without a decorator on the classes inside a namespace.\nThe namespace itself is global, and it is not exported from its file, so the source rightly doesn't have a local named `___exports` to assign to.","author":{"url":"https://github.com/SirWrexes","@type":"Person","name":"SirWrexes"},"datePublished":"2025-05-24T00:13:35.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/1634/TypeScriptToLua/issues/1634"}