In an anonymous class, accessing static class property in instance method via this.constructor is reported as an error (is not an error) [Javascript, but TypeScript checking it]

[gima]

🔎 Search Terms

"class" AND "private" AND ("field" OR "property") AND ("must be declared in an enclosing class" OR "does not exist on type Function") AND "static" AND "this.constructor" AND "private" AND -label:Suggestion

Relevant bugs:

• T.constructor should be of type T #3841
• Suggestion: Improve type of constructor on the instance type of a class #32452

🕗 Version & Regression Information

• The problem exists on the oldest (3.3.3333) and the newest (Nightly, v5.8.0-dev.20241107) of the Playground.
• I reviewed the FAQ and couldn't find anything related to it.

⏯ Playground Link

https://www.typescriptlang.org/play/?filetype=js#code/MYewdgzgLgBA5gUygYQDYEMIRgXhgCgEpcA+AKBkpmAyxgHoAqGAQTHAE8BbEAV2xqZsjejADeFKlOjooAS2AwAxIKwAFAE5yAbrIS4YARgBMAZgDcZSVMoz5ixCloRNOvUXHWbUjUl4awGCgACzkIADoVZ1ddKARLb0oAXytE+CQ0IRi9AFUIOTA4AElIKHQwYAQAWSRgkAATDwk0nz8AoNCI0FKNXmAoEA1I1RctWPivKRSpq27oGGQAGRYAZRWDR0ysIksyOZBUBHDUEDh8GABycM3osfdiHBwLgBoF5bXrjNu3OI9CS32h2OpwIVxuWTucTyBWKpXKlRqIQaHkeLwIYAQAHc3qsVkRCJ8nBCfghoYUSjIKtVasjiP8yEA

💻 Code

const getClass = () =>
    class /* Anonymous class */ {
        static #classPrivate = 123;

        static getClassPrivate() {
            return this.#classPrivate;
        }

        getClassPrivateUsingInstanceMethod() {
            return this.constructor.#classPrivate;
        }
    }

const CLASS = getClass();

console.log( '.getClassPrivate() ==', CLASS.getClassPrivate() );
console.log ('.getClassPrivateUsingInstanceMethod() ==', (new CLASS()).getClassPrivateUsingInstanceMethod() );

Running the above code works. Logs:

[LOG]: ".getClassPrivate() ==",  123 
[LOG]: ".getClassPrivateUsingInstanceMethod() ==",  123 

🙁 Actual behavior

TypeScript checker says there are errors in the code.

Errors in code

    Property '#classPrivate' does not exist on type 'Function'.

🙂 Expected behavior

No errors from TypeScript checker.

Additional information about the issue

The problem goes away when adding // @ts-ignore above the erroring line.

Except

when using VSCode¹ locally, the ts-ignore directive does nothing. If I add // @ts-check at the top of the file, the ts-ignore directive works as expected.

¹ (built-in TypeScript version 5.6.3, Restricted Mode)

[jcalz]

Isn't this a duplicate of #32452, which you linked above? How does this differ? I'd expect both class expressions and class declarations to have the same behavior with regards to the constructor property.

[gima]

Uuuh 😳
❝ Yes, but.

Mine is

• about JavaScript (not TypeScript) code being checked automatically inside VSCode without even configuring anything. Just editing .js files.
• about anonymous classes which Cannot be accessed via the literal class name instead, as suggested (as no such exists).
• way clearer! 😫

And. The following Additional information about the issue might be yet another bug:

The problem goes away when adding // @ts-ignore above the erroring line.
Except when using VSCode¹ locally, the ts-ignore directive does nothing. If I add // @ts-check at the top of the file, the ts-ignore directive works as expected.

[typescript-bot]

This issue has been marked as "Duplicate" and has seen no recent activity. It has been automatically closed for house-keeping purposes.