noUselessSwitchCase

JavaScript (and super languages)

摘要

¥Summary

规则生效日期：v1.0.0

¥Rule available since: v1.0.0
诊断类别：lint/complexity/noUselessSwitchCase

¥Diagnostic Category: lint/complexity/noUselessSwitchCase
此规则为推荐规则，默认启用。

¥This rule is recommended, which means is enabled by default.
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 information。

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

¥Sources:
- 与 unicorn/no-useless-switch-case 相同
  
  ¥Same as unicorn/no-useless-switch-case

如何配置

¥How to configure

1
{
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  "linter": {
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    "rules": {
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      "complexity": {
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        "noUselessSwitchCase": "error"
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      }
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    }
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  }
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}

描述

¥Description

禁止在 switch 语句中使用无用的 case。

¥Disallow useless case in switch statements.

switch 语句可以有可选的 default 子句。

¥A switch statement can optionally have a default clause.

仅当 case 子句中没有匹配项时，才会执行 default 子句。因此，位于 default 子句之前的空 case 子句是无用的。

¥The default clause will be still executed only if there is no match in the case clauses. An empty case clause that precedes the default clause is thus useless.

示例

¥Examples

无效

¥Invalid

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switch (foo) {
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    case 0:
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    default:
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        break;
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    case 1:
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        break;
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}

code-block.js:2:5 lint/complexity/noUselessSwitchCase  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Useless case clause.
  
    1 │ switch (foo) {
  > 2 │     case 0:
      │     ^^^^^^^
    3 │     default:
    4 │         break;
  
  ℹ because the default clause is present:
  
    1 │ switch (foo) {
    2 │     case 0:
  > 3 │     default:
      │     ^^^^^^^^
  > 4 │         break;
      │         ^^^^^^
    5 │     case 1:
    6 │         break;
  
  ℹ Unsafe fix: Remove the useless case.
  
    1 1 │   switch (foo) {
    2   │ - ····case·0:
    3 2 │       default:
    4 3 │           break;

1
switch (foo) {
2
    default:
3
    case 0:
4
        break;
5
    case 1:
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        break;
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}

code-block.js:3:5 lint/complexity/noUselessSwitchCase  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Useless case clause.
  
    1 │ switch (foo) {
    2 │     default:
  > 3 │     case 0:
      │     ^^^^^^^
  > 4 │         break;
      │         ^^^^^^
    5 │     case 1:
    6 │         break;
  
  ℹ because the default clause is present:
  
    1 │ switch (foo) {
  > 2 │     default:
      │     ^^^^^^^^
    3 │     case 0:
    4 │         break;
  
  ℹ Unsafe fix: Remove the useless case.
  
    1 1 │   switch (foo) {
    2   │ - ····default:
    3   │ - ····case·0:
      2 │ + ····default:
    4 3 │           break;
    5 4 │       case 1:

有效

¥Valid

1
switch (foo) {
2
    case 0:
3
        break;
4
    default:
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        break;
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}

1
switch (foo) {
2
    case 0:
3
        break;
4
}

noUselessSwitchCase

摘要

如何配置

描述

示例

无效

有效

相关链接