Repository navigation
3.1rc (js) regression: writing to property of a global variable redefines entire variable type #27099
Description
TypeScript Versions: 3.1.0-rc.20180911, 3.1.0-dev.20180914
Not an issue in 3.1.0-dev.20180831 (bisected to #26908)
Search Terms:
does not exist global write module
Code
// test.js
const INPUT = process.argv;
process.env.ENV_VAR = 'val';
module.exports = INPUT;Run tsc --noEmit --allowJs --checkJs with @types/node available (see below for a non-node example).
Expected behavior:
No error.
Actual behavior:
error TS2339: Property 'argv' does not exist on type 'typeof process'.
Not a problem in typescript code. When all the example lines are present, the definition and type definition of process now point to the process.env.ENV_VAR line instead of to @types/node.
To get the bug, either module.exports needs to be set or a file needs to be required or imported, so I assume it being a module is important. Writing to anything on process seems to trigger it, not just a sub-property (so e.g. process.env = {ENV_VAR: 'val'}; would also trigger the bug, though probably not a good idea in real code :).
Activity
brendankenny commentedon Sep 14, 2018
bisecting leads to #26908.
It seems to occur for any globals, e.g.
It looks like issue #27057 may be the same issue, but I haven't cloned and run the project given in the example to verify.
[-]3.1rc (js) regression: writing to property of global `process` redefines entire 'process' type[/-][+]3.1rc (js) regression: writing to property of global object redefines entire object type[/+][-]3.1rc (js) regression: writing to property of global object redefines entire object type[/-][+]3.1rc (js) regression: writing to property of a global variable redefines entire variable type[/+]sandersn commentedon Sep 14, 2018
Repros on 3.0 with an expando initializer, like
window.name = {}. The bug is more visible now that initializers aren't required to be expandos. The core of the problem is in iniitalizeTypeChecker:CommonJS modules should still merge with globals, because, in JS, the compiler allows undeclared identifiers to act as namespaces in exactly the way assignment to
windowworks.Add a fix for #27099
Fix cross-file merge of assignment decl valueDeclaration (#26918)