`_addIssue` blocks `every`, `some` & `check` actions rewrite due to a possible type issue

[Elton Lobo]

I was trying to rewrite the every action and I ran into this issue.

Issue

FunctionReference<unknown[], TContext> reduces to (...args: unknown[]) => TContext. This creates a problem. Since function parameter types are contravariant (reference: microsoft/TypeScript#18654), the only valid function types that can be assigned are the functions that have unknown or any parameter types (reference: microsoft/TypeScript#24439). This is the type error I get while rewriting the action:

Why did I or any other contributor did not run into this issue earlier while writing actions that were merged to rewrite-with-pipe?
This is because any action's reference passed to _addIssue is reduced to (requirement: unknown, message?: unknown) => <ReturnTypeOfTheActionHere> if the action has two or more overloads with generic parameters. Try commenting the first overload of any action maybe bytes and notice _addIssue creates a type error.

The requirements of every, some and check are functions so they can't be reduced to unknown.

My suggestion

Change FunctionReference<unknown[], TContext> to FunctionReference<any[], TContext> and update all of the relevant affected places. Reading the implementation, I noticed it doesn't really care about the types of the parameters of the function reference passed to _addIssue, so it is safe to use any? 

Your suggestion/guidance?

Do you have a better suggestion? Also, I apologize if this was a false alarm. I am trying to limit the help needed so that the rewrite is as smooth as possible but I will need some guidance for this issue.

Incomplete every implementation so that you can reproduce the issue:

import type { BaseIssue, BaseValidation, ErrorMessage } from '../../types';
import { _addIssue } from '../../utils/index.ts';

/**
 * Every issue type.
 */
export interface EveryIssue<TInput extends unknown[]>
  extends BaseIssue<TInput> {
  /**
   * The issue kind.
   */
  readonly kind: 'validation';
  /**
   * The issue type.
   */
  readonly type: 'every';
  /**
   * The expected input.
   */
  readonly expected: null;
  /**
   * The validation function.
   */
  readonly requirement: (
    element: TInput[number],
    index: number,
    array: TInput[number][]
  ) => boolean;
}

/**
 * Every action type.
 */
export interface EveryAction<
  TInput extends unknown[],
  TMessage extends ErrorMessage<EveryIssue<TInput>> | undefined,
> extends BaseValidation<TInput, TInput, EveryIssue<TInput>> {
  /**
   * The action type.
   */
  readonly type: 'every';
  /**
   * The expected property.
   */
  readonly expects: null;
  /**
   * The validation function.
   */
  readonly requirement: (
    element: TInput[number],
    index: number,
    array: TInput[number][]
  ) => boolean;
  /**
   * The error message.
   */
  readonly message: TMessage;
}

/**
 * Creates an every validation action.
 *
 * @param requirement The validation function.
 *
 * @returns An every action.
 */
export function every<TInput extends unknown[]>(
  requirement: (
    element: TInput[number],
    index: number,
    array: TInput[number][]
  ) => boolean
): EveryAction<TInput, undefined>;

/**
 * Creates an every validation action.
 *
 * @param requirement The validation function.
 * @param message The error message.
 *
 * @returns An every action.
 */
export function every<
  TInput extends unknown[],
  const TMessage extends ErrorMessage<EveryIssue<TInput>> | undefined,
>(
  requirement: (
    element: TInput[number],
    index: number,
    array: TInput[number][]
  ) => boolean,
  message: TMessage
): EveryAction<TInput, TMessage>;

export function every(
  requirement: (element: unknown, index: number, array: unknown[]) => boolean,
  message?: ErrorMessage<EveryIssue<unknown[]>>
): EveryAction<unknown[], ErrorMessage<EveryIssue<unknown[]>> | undefined> {
  return {
    kind: 'validation',
    type: 'every',
    async: false,
    expects: null,
    message,
    requirement,
    _run(dataset, config) {
      if (dataset.typed && !dataset.value.every(this.requirement)) {
        _addIssue(this, every, 'input', dataset, config);
      }
      return dataset;
    },
  };
}

[Fabian Hiller]

Thank you for creating this issue and the detailed context. I am currently refactoring part of the rewrite. This will include a fix for this problem. I plan to add this change to the rewrite-with-pipe branch in the next few hours.

[Fabian Hiller]

Done. Reach out if you have any questions about my changes.