noParametersOnlyUsedInRecursion

JavaScript (and super languages)

摘要

¥Summary

规则生效日期：v2.3.3

¥Rule available since: v2.3.3
诊断类别：lint/nursery/noParametersOnlyUsedInRecursion

¥Diagnostic Category: lint/nursery/noParametersOnlyUsedInRecursion
此规则包含 unsafe 修复程序。

¥This rule has an unsafe fix.
此规则的默认严重级别为 warning。

¥The default severity of this rule is warning.
来源：

¥Sources:
- 灵感来自 only_used_in_recursion
  
  ¥Inspired from only_used_in_recursion

如何配置

¥How to configure

1
{
2
  "linter": {
3
    "rules": {
4
      "nursery": {
5
        "noParametersOnlyUsedInRecursion": "error"
6
      }
7
    }
8
  }
9
}

描述

¥Description

禁止使用仅在递归调用中使用的函数参数。

¥Disallow function parameters that are only used in recursive calls.

仅传递给递归调用的参数实际上未使用，可以删除或替换为常量，从而简化函数。

¥A parameter that is only passed to recursive calls is effectively unused and can be removed or replaced with a constant, simplifying the function.

示例

¥Examples

无效

¥Invalid

1
function factorial(n, acc) {
2
    if (n === 0) return 1;
3
    return factorial(n - 1, acc);
4
}

code-block.js:1:23 lint/nursery/noParametersOnlyUsedInRecursion  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This parameter is only used in recursive calls.
  
  > 1 │ function factorial(n, acc) {
      │                       ^^^
    2 │     if (n === 0) return 1;
    3 │     return factorial(n - 1, acc);
  
  ℹ Parameters that are only used in recursive calls are effectively unused and can be removed.
  
  ℹ If the parameter is needed for the recursion to work, consider if the function can be refactored to avoid it.
  
  ℹ Unsafe fix: If this is intentional, prepend acc with an underscore.
  
    1   │ - function·factorial(n,·acc)·{
      1 │ + function·factorial(n,·_acc)·{
    2 2 │       if (n === 0) return 1;
    3   │ - ····return·factorial(n·-·1,·acc);
      3 │ + ····return·factorial(n·-·1,·_acc);
    4 4 │   }
    5 5 │

1
function countdown(n, step) {
2
    if (n === 0) return 0;
3
    return countdown(n - step, step);
4
}

code-block.js:1:23 lint/nursery/noParametersOnlyUsedInRecursion  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This parameter is only used in recursive calls.
  
  > 1 │ function countdown(n, step) {
      │                       ^^^^
    2 │     if (n === 0) return 0;
    3 │     return countdown(n - step, step);
  
  ℹ Parameters that are only used in recursive calls are effectively unused and can be removed.
  
  ℹ If the parameter is needed for the recursion to work, consider if the function can be refactored to avoid it.
  
  ℹ Unsafe fix: If this is intentional, prepend step with an underscore.
  
    1   │ - function·countdown(n,·step)·{
      1 │ + function·countdown(n,·_step)·{
    2 2 │       if (n === 0) return 0;
    3   │ - ····return·countdown(n·-·step,·step);
      3 │ + ····return·countdown(n·-·_step,·_step);
    4 4 │   }
    5 5 │

1
class Counter {
2
    count(n, acc) {
3
        if (n === 0) return 0;
4
        return this.count(n - 1, acc);
5
    }
6
}

code-block.js:2:14 lint/nursery/noParametersOnlyUsedInRecursion  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This parameter is only used in recursive calls.
  
    1 │ class Counter {
  > 2 │     count(n, acc) {
      │              ^^^
    3 │         if (n === 0) return 0;
    4 │         return this.count(n - 1, acc);
  
  ℹ Parameters that are only used in recursive calls are effectively unused and can be removed.
  
  ℹ If the parameter is needed for the recursion to work, consider if the function can be refactored to avoid it.
  
  ℹ Unsafe fix: If this is intentional, prepend acc with an underscore.
  
    1 1 │   class Counter {
    2   │ - ····count(n,·acc)·{
      2 │ + ····count(n,·_acc)·{
    3 3 │           if (n === 0) return 0;
    4   │ - ········return·this.count(n·-·1,·acc);
      4 │ + ········return·this.count(n·-·1,·_acc);
    5 5 │       }
    6 6 │   }

1
function fn(n, acc) {
2
    if (n === 0) return 0;
3
    return fn(n - 1, acc || 0);
4
}

code-block.js:1:16 lint/nursery/noParametersOnlyUsedInRecursion  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This parameter is only used in recursive calls.
  
  > 1 │ function fn(n, acc) {
      │                ^^^
    2 │     if (n === 0) return 0;
    3 │     return fn(n - 1, acc || 0);
  
  ℹ Parameters that are only used in recursive calls are effectively unused and can be removed.
  
  ℹ If the parameter is needed for the recursion to work, consider if the function can be refactored to avoid it.
  
  ℹ Unsafe fix: If this is intentional, prepend acc with an underscore.
  
    1   │ - function·fn(n,·acc)·{
      1 │ + function·fn(n,·_acc)·{
    2 2 │       if (n === 0) return 0;
    3   │ - ····return·fn(n·-·1,·acc·||·0);
      3 │ + ····return·fn(n·-·1,·_acc·||·0);
    4 4 │   }
    5 5 │

1
class Counter {
2
    count(n, acc) {
3
        if (n === 0) return 0;
4
        return this?.count(n - 1, acc);
5
    }
6
}

code-block.js:2:14 lint/nursery/noParametersOnlyUsedInRecursion  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━

  ⚠ This parameter is only used in recursive calls.
  
    1 │ class Counter {
  > 2 │     count(n, acc) {
      │              ^^^
    3 │         if (n === 0) return 0;
    4 │         return this?.count(n - 1, acc);
  
  ℹ Parameters that are only used in recursive calls are effectively unused and can be removed.
  
  ℹ If the parameter is needed for the recursion to work, consider if the function can be refactored to avoid it.
  
  ℹ Unsafe fix: If this is intentional, prepend acc with an underscore.
  
    1 1 │   class Counter {
    2   │ - ····count(n,·acc)·{
      2 │ + ····count(n,·_acc)·{
    3 3 │           if (n === 0) return 0;
    4   │ - ········return·this?.count(n·-·1,·acc);
      4 │ + ········return·this?.count(n·-·1,·_acc);
    5 5 │       }
    6 6 │   }

有效

¥Valid

1
function factorial(n, acc) {
2
    if (n === 0) return acc;
3
    return factorial(n - 1, acc * n);
4
}

1
function countdown(n, step) {
2
    console.log(step);
3
    if (n === 0) return 0;
4
    return countdown(n - step, step);
5
}

1
function fn(n, threshold) {
2
    if (n > threshold) return n;
3
    return fn(n + 1, threshold);
4
}

noParametersOnlyUsedInRecursion

摘要

如何配置

描述

示例

无效

有效

相关链接