Strongly typing the invoke function

[floydjdx]

Current behavior:

invoke function is not strongly typed.

Desired behavior:

invoke function is strongly typed.

TypeScript has a ReturnType type that you can use

invoke<K extends keyof Subject>(functionName: K, ...args: any[]): Chainable<ReturnType<Subject[K]>>

[flotwig]

Hey, thanks for pointing this out!

The types definition file that needs to be updated is here: https://github.com/cypress-io/cypress/blob/develop/cli/types/index.d.ts

If you'd like to, you can open a pull request with the changes that you think are necessary.

[cypress-bot]

The code for this is done in cypress-io/cypress#4907, but has yet to be released.
We'll update this issue and reference the changelog when it's released.

[bahmutov]

Reverted initial work in 6930cab - we need to handle the case

cy.get('.trigger-input-range')
  .invoke('val', 25)

[dmtrKovalenko]

The problem is inside function overloading. Typescript takes only the first function declaration signature. Related issues in typescript repo:
microsoft/TypeScript#29732
microsoft/TypeScript#32164

[gabbersepp]

I understand that this is not the best solution as overloads won't work as expected.
But they won't work currently neither.

With this fix the typings ovf invoke will be correct in most of the cases.

An example I stumbled across today:

        it.only("asd", () => {
            cy.wrap({ fn: () => ({a: 1})})
            .invoke("fn")
            .its("a")
            .should('eq', 1);
        })

So I wanted to know if there are any plans to merge this PR again?

[CypressJoseph]

I think this is basically done as of #6667 (I will look again but I think we tackled most of these forms there.)

[cypress-bot]

Released in 4.2.0.

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