Unwanted auto-imports in script files

[HolgerJeromin]

Bug Report

I have a mixture of module and non-module code.
The problem occurs when I edit non-module files (tsconfig: "module": "none").

Sometimes when using auto-completion (in VisualStudio 2022) typescript finds a "matching" name from the module world and adds a line like

import { HmiHelper } from './helper/HmiHelper.js';

into the first line of my file.
But as the current file was configured as "module": "none" this import pushes typescript into modules mode and the current code is invalid.

🔎 Search Terms

intellisense
auto-import
modules

🕗 Version & Regression Information

This bug is many years old and persists in Typescript 5.1.

[RyanCavanaugh]

The title seems backwards; do you mean "with module: none" ?

[hardikkoul]

If this is still not resolved or assigned to anyone, may i have a go ?

[HolgerJeromin]

@hardikkoul Just go for it:
https://github.com/Microsoft/TypeScript/blob/main/CONTRIBUTING.md#issue-claiming

Hmm, after rereading the link: This issue do not have a "help wanted" or "Backlog" tag...

[andrewbranch]

@hardikkoul fine by me 👍 There’s a function shouldOfferImportCompletions or something like that in completions.ts.

[hardikkoul]

@HolgerJeromin , @andrewbranch thanks , will start analyzing.

[hardikkoul]

I can see there is a method programContainsModules , so its already checking for module config , but the catch is it only executes when none of the other conditions of shouldOfferImportCompletions return true. Correct me if my understanding is wrong.

[andrewbranch]

You can just add a check that module isn’t none higher up, or change compilerOptionsIndicateEsModules (already a nonsense function, as my old TODO comment notes)

[hardikkoul]

Let me know if it needs any revisions or is totally wrong (which is a possibility :P) , i opted not to touch the existing method just in case something breaks.

[hardikkoul]

Sorry for the mess up while resolving conflicts @andrewbranch , i have closed and deleted the previous PR and branch , have created a new branch and raised a PR without conflicts, please review
#55556

[HolgerJeromin]

cc @andrewbranch

Moving the discussion from the merged PR to this issue. Please reopen because the PR does not change behaviour.

ref #55556 (comment)

I do not understand. With typescript ts5.2.2 I still get bogus, file breaking autosuggestions in my modules:none code

If you accept the import, do you get an error?

Yes. My code is something like this non-module file with namespaces and a 3.7 MByte outfile:

namespace TcHmi.Config {
    export function get() {
        return TcHmi.System.config;  // <-- Defined in some other file 
    }
}

If I accept the auto-import

I will get this code:

import { parse } from "acorn";

namespace TcHmi.Config {
    export function get() {
        parse
        return TcHmi.System.config;  // <-- Defined in some other file 
    }
}

Typescript handles this code as a module and correctly has not idea what TcHmi.System should be.

I have "include": ["Lib/acorn.d.ts", ... in my tsconfig.json which this reduced content:

declare namespace acorn {  // I access this namespace
    /*...*/
    function parse(input: string, options?: Options): ESTree.Program;
}
declare module "acorn" {
    export = acorn
}

[andrewbranch]

Ok, I see. The import is allowed, but turning your file into a module causes other errors. But that may be the case in any module mode, so it’s not really related to --module none. The truth is that --module none just doesn’t mean anything when --target is es2015 or higher, and I’m a little uncomfortable with forcing more meaning onto it than it has.

We could possibly consider preventing auto-imports when there is a top-level namespace declaration in a script that already merges with one in another file.

[HolgerJeromin]

@andrewbranch
Could you please reopen this issue because the PR did not changed typescript code at all.
I still get this bogus suggestion with typescript 5.3.
Opening another issue feels not nice.

[andrewbranch]

Accepting PRs for this:

We could possibly consider preventing auto-imports when there is a top-level namespace declaration in a script that already merges with one in another file.

[HolgerJeromin]

Found #35395

Moving
typescript.preferences.autoImportFileExcludePatterns
from vscode settings to tsconfig setting would help visual studio 2022 users (like us) too with this very issue.
Edit: or create a vs setting for that.