sindresorhus/eslint-plugin-unicorn

Rule proposal: Enforce `.toArray()` at the end of `Iterator` methods chain

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#2,767 创建于 2025年9月25日

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help wantednew rule

描述

Description

Note that it's a good idea to call toArray() as a last step of your processing. For example, fibonacci().take(10).toArray().filter(...) is less efficient, because iterator helpers are lazy and avoids creating a temporary array.

From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/toArray

Examples

// ❌
foo.toArray().filter(...)
//            ^^^^^^ Array#filter()

// ✅
foo.filter(...).toArray()
//  ^^^^^^ Iterator#filter()

Proposed rule name

not sure

Additional Info

No response

贡献者指南

技术栈
javascript
领域
tooling
议题类型
feature
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
half day
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
fresh
清晰度议题是否清楚说明期望改动、验收标准和下一步。
mostly clear
前置要求
Understanding of ESLint plugin architectureFamiliarity with AST (Abstract Syntax Tree)Basic knowledge of JavaScript iterators
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
70
研究方向
Review existing rule implementations in the plugin (e.g., 'prefer array flat map') as a reference. Examine the AST for calls like `foo.toArray().filter(...)` and determine how to detect when `.toArray()` is called before other array methods instead of after iterator methods. Consider using ESLint's `MemberExpression` and `CallExpression` nodes. The issue lacks a proposed rule name; comment to suggest a name based on naming conventions.
Rule proposal: Enforce `.toArray()` at the end of `Iterator` methods chain · sindresorhus/eslint-plugin-unicorn#2767 | Good First Issue