[TS] Suggestions don't show up for objects with an index signature

Permanently deleted user

Created June 28, 2019 02:32

I am writing TypeScript with WebStorm. I have an object with a string index signature like the example below:

const STRINGS: { [key: string]: string } = {
 modal_valueTh: 'Value TH',
 modal_valueEn: 'Value EN',
};

When I open the suggestion box, it doesn't list all the properties in `STRINGS` object.

As soon as I delete the index signature, making my code like this:

const STRINGS = {
 modal_valueTh: 'Value TH',
 modal_valueEn: 'Value EN',
};

the suggestions then appear.

Is this a problem with WebStorm, auto completion or my code?

1 comment

Elena Pogorelova

Created June 28, 2019 12:09

Completion doesn't work in this case because TypeScript is statically typed, and the static type is { [key: string]: string } which obviously doesn't have any properties.

When you add a type annotation like : {[key: string]:string}, it gains a priority over the right part of assignment, so the right part is completely ignored, and variable type is just a type with a single indexer. This is how TypeScript works, and adding the indexer type ruins the static type checking.

See https://stackoverflow.com/questions/52146544/why-autocomplete-stop-working-in-an-object-with-type-in-typescript/52157355#52157355

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