sindresorhus/type-fest

`Proposal`: add option with exclude/keep specified type on deep type

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#862 opened on Apr 12, 2024

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 (5 comments) (0 reactions) (1 assignee)TypeScript (12,328 stars) (471 forks)batch import
help wantedtype addition

Description

Look at this scene

I have a type Item that wrapped with some util type, and I want get a simplify Item, like:

import type { SimplifyDeep } from 'type-fest/source/merge-deep'

type SimplifyItem = SimplifyDeep<Item>
// => expect type SimplifyItem = { name: string, color: THREE.Color }

but actual rsult is:

import type { SimplifyDeep } from 'type-fest/source/merge-deep'

type SimplifyItem = SimplifyDeep<Item>
/**
type SimplifyItem = { 
    name: string,
    color: {
            readonly isColor: true;
            r: number;
            g: number;
            b: number;
            set: (color: string | number | Color) => Color;
            ... 31 more ...;
            toArray: {
                ...;
            };
        };
}
*/

so maybe we can add a exclude type option ( or named keep ) on Deep type like:

import type { SimplifyDeep } from 'type-fest/source/merge-deep'

type SimplifyItem = SimplifyDeep<Item, { exclude: THREE.Color }>
// => expect type SimplifyItem = { name: string, color: THREE.Color }

It can also resolve scene conflicts between users, such as one want recursive into HTMLElemet, anther one want keep HTMLElemet

Related comment: https://github.com/sindresorhus/type-fest/issues/651#issuecomment-1803324362 Related issue: #651

Contributor guide

Tech stack
typescript
Domain
developer experiencetooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
TypeScript advanced typesfamiliarity with type fest
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
The issue proposes adding an optional `exclude` (or `keep`) parameter to the `SimplifyDeep` type to prevent deep recursion on specific types like `THREE.Color` or `HTMLElement`. Examine the existing implementation in `source/merge deep.ts` (likely the `SimplifyDeep` type) to understand how to add a generic parameter that filters out specified types. Review related issue #651 and the linked comment for additional context. Consider if maintainer has indicated acceptance or design preferences.