Don't suggest private fields in contexts where they are out of scope

[Jamesernator]

🔎 Search Terms

private fields suggestions

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about private fields

⏯ Playground Link

https://www.typescriptlang.org/play?#code/C4TwDgpgBAogHgQwLZgDYQJIDsCWwoC8UA3gFBQVQBmA9jQFxRYCuSARhAE4A0pAvgG5SpUJFiIU6ADI4A1tCLxkaaAB9xy9NjxDSAY1QIAzkY2ToZSlCPAEwHHqg4jS8wAoAbglTMIjBFggAJSMXj7QzmYqJORWlJwQwMycWFAAxLQ0TqlhvkJWfMJWNnYO1Jw0SG4QEioy8oyudXIQIVHoMXGUOFRQbk3oAHTOAxDVtdItQUGdXXEJSSlQNZoQ9RD5c4VzUAvJqVgQAO7tYyvm60GbFIWxFAkIACY0WKgg6ZmMLOxculZ6LxsnGYemANE4bmI1DoUD4jQmmFwwBmljmwAAFs5BhkYURMtdYfxhACsDZlgjCKdBlQKlVURQAPQMqAAFU471EOCwAHMoAAiKh8qABR7WCDQDF2KAYrgRUwIazMbnciA2HAvaGcD50fhXUhAA

💻 Code

type ExampleInit = {
 foo: number,
};

type ExampleLike = Example | ExampleInit;

class Example {
 static isExample(value: any): value is Example {
 return #foo in value;
 }

 static from(exampleLike: ExampleLike): Example {
 if (Example.isExample(exampleLike)) {
 return exampleLike;
 }
 return new Example(exampleLike);
 }

 readonly #foo: number;

 constructor({ foo }: ExampleInit) {
 this.#foo = foo;
 }
}

const example = Example.from({
 // Try typing "f" and see that there is a suggestion for #foo
});

🙁 Actual behavior

We get suggestions for private fields:

This is particularly annoying as the private fields tend to be suggested first, so tab-completion tends to produce broken code.

🙂 Expected behavior

The private field should not be included as a suggestion when outside the class scope where the field is defined.

Additional information about the issue

No response

[fatcerberus]

Since the proposal is to make this context-sensitive anyway: Technically you shouldn't get suggested anything from Example (not even public properties) in this context because the existence of a private property means the type can't possibly be satisfied by a bare object literal. The only type that object literal can satisfy is ExampleInit.

[RyanCavanaugh]

A private property can be optional, so it's possible that it's possible to instantiate with an object literal

[fatcerberus]

Does it ever make sense for a #private field to be optional? You can instantiate such a type with an object literal in theory, but any method that tries to access the property on that object will error at runtime--optional or not.

[trusktr]

Just fyi the autocomplete suggestion produces code that becomes a SyntaxError at runtime.