bug: Overly restrictive type for `filter` in `RefetchAfterMutationItem`

[ericbf]

Using the object type for variables in the filter definition causes you to not be able to index the variables object for any values, nor easily define the type in the function definition. You’re forced to do a type cast to use the filter in any reasonable way. See the originating comment.

refetchAfterMutations: {
	mutation: `...`,
	// Error: Property 'id' does not exist on type 'object'.ts(2339)
	filter: (vars) => vars.id === id
}

// Error: Types of parameters 'vars' and 'variables' are incompatible.
//        Property 'id' is missing in type '{}' but required in type '{ id: string; }'.ts(2322)
refetchAfterMutations: { 
	mutation: `...`,
	filter: (vars: { id: string }) => vars.id === id
}

// Works, but is clunky
refetchAfterMutations: {
	mutation: `...`,
	filter: (vars) => (vars as { id: string }).id === id
}

Using object essentially prevents you from easily working with the variables param.

I propose we actually do use any as the type for this parameter:

export type RefetchAfterMutationItem = {
  mutation: string
  filter?: (variables: any) => boolean
}

This is saying that the filter props is a function that accepts a parameter and returns a boolean—this is essentially what we want here. If you can find a type that allows the consumer to set the type easily, that’s not any, that would also work.

As the consumer of this function, you could type it more strongly if desired:

// Would work now
refetchAfterMutations: { 
	mutation: `...`,
	filter: (vars: { id: string }) => vars.id === id
}

graphql-hooks/packages/graphql-hooks/src/types/common-types.ts

Lines 182 to 185 in 8a0bec1

	export type RefetchAfterMutationItem = {
	mutation: string
	filter?: (variables: object) => boolean
	}