Argument of type Record<string, string> is not assignable to parameter of type Traits | Callback | null | undefined

[zygopleural]

Breaking change introduced

I have a breaking change trying to upgrade 1.41.0 -> 1.42.1

Expected

I should be able to pass any Record<string, string | number | JSONValue> as traits into the identify call.

Actual

I can only only pass Record<string, JSONValue>

Culprit

Looks like here was a breaking change in @segment/analytics-next@1.42.0

I believe #561 is the culprit, specifically these changes

[silesky]

@zygopleuralI Thanks for taking out an issue. I wasn't able to reproduce --

// This works
const traits: Record<string, string> =  {name: "hello"}
analyics.identify("foo", traits) 

https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAbzgQQHYEMA2BPGwDGAzgEJQQDuhAplADQoY55FwC+cAZmSHAOQAC1AOYgqqGAHp0jXAUIBaVFQAeMXgChNm-BFSF4MKOmAxCALjgAlKjqgATADz6owVEPrPXQgHxwAvHCIGKIWAEQAFlSYmBChrADc6gAUCOzohAxYskQAlAB0wHZieBzYSaEcELH0hsamOVpAA

FYI, the definition of JSONValue already contains string | number, so Record<string, JSONValue> is the same as Record<string, string | number | JSONValue>

// This works
const traits: Record<string, JSONValue | string | number> =  {name: "hello"};
analytics.identify("foo", traits)

Is there a more advanced type you're having problems with?

[zygopleural]

const { id, picture, signInMethod, ...traits } = user
identify(id, traits)

I'm seeing

Even if I do

const t = traits as Traits

[silesky]

@zygopleural Thank you for the detail, that's an interesting one, and will be a problem if anyone attempts to coerce an object created with that pattern to a Record type. For now, you can fix by casting traits to "object" or by creating a UserTraits type like this:

type UserTraits = {
  name: string
  age: string
}
const { id, picture, signInMethod, ...traits } = user
identify(id, traits as UserTraits)

[silesky]

@zygopleural fixed in 1.42.2 1.42.3

[silesky]

FYI @zygopleural there is an open Typescript issue about this scenario / bug: microsoft/TypeScript#48014

[zygopleural]

FYI @zygopleural there is an open Typescript issue about this scenario / bug: microsoft/TypeScript#48014

Ah nice find!