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Template string wrongly infers type from a default value used in destructuring assignmentΒ #55907
Description
π Search Terms
"template string", "default value", "infer type", "destructuring"
π Version & Regression Information
This changed between versions 5.1.6 and 5.2.2. The bug is also present in 5.3.0-dev.20230928.
β― Playground Link
π» Code
type Params = {
value?: string | number
}
function example(parameters: Params) {
const { value = '123' } = parameters
return `${value}` === '345' // <--- Error: This comparison appears to be unintentional because the types '"123"' and '"345"' have no overlap.(2367)
}π Actual behavior
The template string expression, ${value}, is assigned type "123", based on a default value assigned to value in a destructing assignment.
π Expected behavior
The expression should instead be assigned a type of string. The field value is correctly assigned a type of string | number, so any template string using value should not be restricted to the default value used in destructuring.
Additional information about the issue
No response
Activity
[-]Template strings wrongly infer type from a default value used in destructuring assignment[/-][+]Template string wrongly infers type from a default value used in destructuring assignment[/+]Andarist commentedon Sep 29, 2023
I'm almost certain that this is a fall out of #53907 and it's definitely a bug. I'll look into this soon.
LasAtt commentedon Sep 29, 2023
Thank you for looking into it!
Andarist commentedon Sep 29, 2023
It's actually an old bug but this one is a new manifestation of it. TS playground