toInclude*Members should be declared with readonly arguments

[bogdanb]

Bug

• jest-extended version: 0.11.5
• node version: 14.7.0
• npm (or yarn) version: 6.14.8

Relevant code or config

const expected : readonly number[] = [1, 2, 3];
expect ([...expected]).toIncludeAllMembers(expected);

What you did: Running code like the above (this is much simplified) leads to TypeScript complaining with an error like this:

TS2345: Argument of type 'readonly number[]' is not assignable to parameter of type 'any[]'.
The type 'readonly number[]' is 'readonly' and cannot be assigned to the mutable type 'any[]'.

What happened (please provide anything you think will help):

The issue is that all the matchers are declared like this:

toIncludeSameMembers(members: any[]): R;

They should probably have been declared like this:

toIncludeSameMembers(members: readonly any[]): R;

Because the matcher never needs to mutate the array. As far as I can tell, the following matchers are affected:

• toBeOneOf
• toIncludeAllMembers
• toIncludeAnyMembers
• toIncludeSameMembers
• toContainKeys
• toContainAllKeys
• toContainAnyKeys
• toContainValues
• toContainAllValues
• toContainAnyValues
• toContainEntries
• toContainAllEntries
• toContainAnyEntries
• toIncludeMultiple

This applies to both jest.Matchers and jest.Expect interfaces.