Rules
Rules in ESLint are grouped by category to help you understand their purpose.
为了让你对规则有个更好的理解,ESLint 对其进行了分门别类。
No rules are enabled by default. The "extends": "eslint:recommended" property in a configuration file enables rules that report common problems, which have a check mark  below.
所有的规则默认都是禁用的。在配置文件中,使用 "extends": "eslint:recommended" 来启用推荐的规则,报告一些常见的问题,在下文中这些推荐的规则都带有一个标记。
The --fix option on the command line automatically fixes problems (currently mostly whitespace) reported by rules which have a wrench  below.
命令行的 --fix 选项用来自动修复规则所报告的问题(目前,大部分是对空白的修复),在下文中会有一个的图标。
Possible Errors
These rules relate to possible syntax or logic errors in JavaScript code:
这些规则与 JavaScript 代码中可能的错误或逻辑错误有关:
| enforce “for” loop update clause moving the counter in the right direction. | |||
| 强制 “for” 循环中更新子句的计数器朝着正确的方向移动 | |||
| enforce  | |||
| 强制 getter 函数中出现  | |||
| disallow using an async function as a Promise executor | |||
| 禁止使用异步函数作为 Promise executor | |||
| disallow  | |||
| 禁止在循环中出现  | |||
| disallow comparing against -0 | |||
| 禁止与 -0 进行比较 | |||
| disallow assignment operators in conditional expressions | |||
| 禁止条件表达式中出现赋值操作符 | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow constant expressions in conditions | |||
| 禁止在条件中使用常量表达式 | |||
| disallow control characters in regular expressions | |||
| 禁止在正则表达式中使用控制字符 | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow duplicate arguments in  | |||
| 禁止  | |||
| disallow duplicate keys in object literals | |||
| 禁止对象字面量中出现重复的 key | |||
| disallow duplicate case labels | |||
| 禁止出现重复的 case 标签 | |||
| disallow empty block statements | |||
| 禁止出现空语句块 | |||
| disallow empty character classes in regular expressions | |||
| 禁止在正则表达式中使用空字符集 | |||
| disallow reassigning exceptions in  | |||
| 禁止对  | |||
| disallow unnecessary boolean casts | |||
| 禁止不必要的布尔转换 | |||
| disallow unnecessary parentheses | |||
| 禁止不必要的括号 | |||
| disallow unnecessary semicolons | |||
| 禁止不必要的分号 | |||
| disallow reassigning  | |||
| 禁止对  | |||
| disallow variable or  | |||
| 禁止在嵌套的块中出现变量声明或  | |||
| disallow invalid regular expression strings in  | |||
| 禁止  | |||
| disallow irregular whitespace | |||
| 禁止不规则的空白 | |||
| disallow characters which are made with multiple code points in character class syntax | |||
| 不允许在字符类语法中出现由多个代码点组成的字符 | |||
| disallow calling global object properties as functions | |||
| 禁止把全局对象作为函数调用 | |||
| disallow calling some  | |||
| 禁止直接调用  | |||
| disallow multiple spaces in regular expressions | |||
| 禁止正则表达式字面量中出现多个空格 | |||
| disallow sparse arrays | |||
| 禁用稀疏数组 | |||
| disallow template literal placeholder syntax in regular strings | |||
| 禁止在常规字符串中出现模板字面量占位符语法 | |||
| disallow confusing multiline expressions | |||
| 禁止出现令人困惑的多行表达式 | |||
| disallow unreachable code after  | |||
| 禁止在  | |||
| disallow control flow statements in  | |||
| 禁止在  | |||
| disallow negating the left operand of relational operators | |||
| 禁止对关系运算符的左操作数使用否定操作符 | |||
| disallow assignments that can lead to race conditions due to usage of  | |||
| 禁止由于  | |||
| require calls to  | |||
| 要求使用  | |||
| enforce comparing  | |||
| 强制  | 
Best Practices
These rules relate to better ways of doing things to help you avoid problems:
这些规则是关于最佳实践的,帮助你避免一些问题
| enforce getter and setter pairs in objects | |||
| 强制 getter 和 setter 在对象中成对出现 | |||
| enforce  | |||
| 强制数组方法的回调函数中有  | |||
| enforce the use of variables within the scope they are defined | |||
| 强制把变量的使用限制在其定义的作用域范围内 | |||
| enforce that class methods utilize  | |||
| 强制类方法使用  | |||
| enforce a maximum cyclomatic complexity allowed in a program | |||
| 指定程序中允许的最大环路复杂度 | |||
| require  | |||
| 要求  | |||
| enforce consistent brace style for all control statements | |||
| 强制所有控制语句使用一致的括号风格 | |||
| require  | |||
| 要求  | |||
| enforce consistent newlines before and after dots | |||
| 强制在点号之前和之后一致的换行 | |||
| enforce dot notation whenever possible | |||
| 强制尽可能地使用点号 | |||
| require the use of  | |||
| 要求使用  | |||
| require  | |||
| 要求  | |||
| enforce a maximum number of classes per file | |||
| 强制每个文件中包含的的类的最大数量 | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow lexical declarations in case clauses | |||
| 不允许在 case 子句中使用词法声明 | |||
| disallow division operators explicitly at the beginning of regular expressions | |||
| 禁止除法操作符显式的出现在正则表达式开始的位置 | |||
| disallow  | |||
| 禁止  | |||
| disallow empty functions | |||
| 禁止出现空函数 | |||
| disallow empty destructuring patterns | |||
| 禁止使用空解构模式 | |||
| disallow  | |||
| 禁止在没有类型检查操作符的情况下与  | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow extending native types | |||
| 禁止扩展原生类型 | |||
| disallow unnecessary calls to  | |||
| 禁止不必要的  | |||
| disallow unnecessary labels | |||
| 禁用不必要的标签 | |||
| disallow fallthrough of  | |||
| 禁止  | |||
| disallow leading or trailing decimal points in numeric literals | |||
| 禁止数字字面量中使用前导和末尾小数点 | |||
| disallow assignments to native objects or read-only global variables | |||
| 禁止对原生对象或只读的全局对象进行赋值 | |||
| disallow shorthand type conversions | |||
| 禁止使用短符号进行类型转换 | |||
| disallow variable and  | |||
| 禁止在全局范围内使用变量声明和  | |||
| disallow the use of  | |||
| 禁止使用类似  | |||
| disallow  | |||
| 禁止  | |||
| disallow the use of the  | |||
| 禁用  | |||
| disallow labeled statements | |||
| 禁用标签语句 | |||
| disallow unnecessary nested blocks | |||
| 禁用不必要的嵌套块 | |||
| disallow function declarations that contain unsafe references inside loop statements | |||
| 禁止在循环语句中出现包含不安全引用的函数声明 | |||
| disallow magic numbers | |||
| 禁用魔术数字 | |||
| disallow multiple spaces | |||
| 禁止使用多个空格 | |||
| disallow multiline strings | |||
| 禁止使用多行字符串 | |||
| disallow  | |||
| 禁止使用  | |||
| disallow  | |||
| 禁止对  | |||
| disallow  | |||
| 禁止对  | |||
| disallow octal literals | |||
| 禁用八进制字面量 | |||
| disallow octal escape sequences in string literals | |||
| 禁止在字符串中使用八进制转义序列 | |||
| disallow reassigning  | |||
| 禁止对  | |||
| disallow the use of the  | |||
| 禁用  | |||
| disallow variable redeclaration | |||
| 禁止多次声明同一变量 | |||
| disallow certain properties on certain objects | |||
| 禁止使用对象的某些属性 | |||
| disallow assignment operators in  | |||
| 禁止在  | |||
| disallow unnecessary  | |||
| 禁用不必要的  | |||
| disallow  | |||
| 禁止使用  | |||
| disallow assignments where both sides are exactly the same | |||
| 禁止自我赋值 | |||
| disallow comparisons where both sides are exactly the same | |||
| 禁止自身比较 | |||
| disallow comma operators | |||
| 禁用逗号操作符 | |||
| disallow throwing literals as exceptions | |||
| 禁止抛出异常字面量 | |||
| disallow unmodified loop conditions | |||
| 禁用一成不变的循环条件 | |||
| disallow unused expressions | |||
| 禁止出现未使用过的表达式 | |||
| disallow unused labels | |||
| 禁用出现未使用过的标 | |||
| disallow unnecessary calls to  | |||
| 禁止不必要的  | |||
| disallow unnecessary  | |||
| 禁止不必要的  | |||
| disallow unnecessary concatenation of literals or template literals | |||
| 禁止不必要的字符串字面量或模板字面量的连接 | |||
| disallow unnecessary escape characters | |||
| 禁用不必要的转义字符 | |||
| disallow redundant return statements | |||
| 禁止多余的 return 语句 | |||
| disallow  | |||
| 禁用  | |||
| disallow specified warning terms in comments | |||
| 禁止在注释中使用特定的警告术语 | |||
| disallow  | |||
| 禁用  | |||
| enforce using named capture group in regular expression | |||
| 建议在正则表达式中使用命名捕获组 | |||
| require using Error objects as Promise rejection reasons | |||
| 要求使用 Error 对象作为 Promise 拒绝的原因 | |||
| enforce the consistent use of the radix argument when using  | |||
| 强制在  | |||
| disallow async functions which have no  | |||
| 禁止使用不带  | |||
| enforce the use of  | |||
| 强制在 RegExp 上使用  | |||
| require  | |||
| 要求所有的  | |||
| require parentheses around immediate  | |||
| 要求 IIFE 使用括号括起来 | |||
| require or disallow “Yoda” conditions | |||
| 要求或禁止 “Yoda” 条件 | 
Strict Mode
These rules relate to strict mode directives:
该规则与使用严格模式和严格模式指令有关:
| require or disallow strict mode directives | |||
| 要求或禁止使用严格模式指令 | 
Variables
These rules relate to variable declarations:
这些规则与变量声明有关:
| require or disallow initialization in variable declarations | |||
| 要求或禁止  | |||
| disallow deleting variables | |||
| 禁止删除变量 | |||
| disallow labels that share a name with a variable | |||
| 不允许标签与变量同名 | |||
| disallow specified global variables | |||
| 禁用特定的全局变量 | |||
| disallow variable declarations from shadowing variables declared in the outer scope | |||
| 禁止变量声明与外层作用域的变量同名 | |||
| disallow identifiers from shadowing restricted names | |||
| 禁止将标识符定义为受限的名字 | |||
| disallow the use of undeclared variables unless mentioned in  | |||
| 禁用未声明的变量,除非它们在  | |||
| disallow initializing variables to  | |||
| 禁止将变量初始化为  | |||
| disallow the use of  | |||
| 禁止将  | |||
| disallow unused variables | |||
| 禁止出现未使用过的变量 | |||
| disallow the use of variables before they are defined | |||
| 禁止在变量定义之前使用它们 | 
Node.js and CommonJS
These rules relate to code running in Node.js, or in browsers with CommonJS:
这些规则是关于Node.js 或 在浏览器中使用CommonJS 的:
| require  | |||
| 强制数组方法的回调函数中有  | |||
| require  | |||
| 要求  | |||
| require error handling in callbacks | |||
| 要求回调函数中有容错处理 | |||
| disallow use of the  | |||
| 禁用  | |||
| disallow  | |||
| 禁止混合常规变量声明和  | |||
| disallow  | |||
| 禁止调用  | |||
| disallow string concatenation with  | |||
| 禁止对  | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow the use of  | |||
| 禁用  | |||
| disallow specified modules when loaded by  | |||
| 禁用通过  | |||
| disallow synchronous methods | |||
| 禁用同步方法 | 
Stylistic Issues
These rules relate to style guidelines, and are therefore quite subjective:
这些规则是关于风格指南的,而且是非常主观的:
| enforce linebreaks after opening and before closing array brackets | |||
| 在数组开括号后和闭括号前强制换行 | |||
| enforce consistent spacing inside array brackets | |||
| 强制数组方括号中使用一致的空格 | |||
| enforce line breaks after each array element | |||
| 强制数组元素间出现换行 | |||
| disallow or enforce spaces inside of blocks after opening block and before closing block | |||
| 禁止或强制在代码块中开括号前和闭括号后有空格 | |||
| enforce consistent brace style for blocks | |||
| 强制在代码块中使用一致的大括号风格 | |||
| enforce camelcase naming convention | |||
| 强制使用骆驼拼写法命名约定 | |||
| enforce or disallow capitalization of the first letter of a comment | |||
| 强制或禁止对注释的第一个字母大写 | |||
| require or disallow trailing commas | |||
| 要求或禁止末尾逗号 | |||
| enforce consistent spacing before and after commas | |||
| 强制在逗号前后使用一致的空格 | |||
| enforce consistent comma style | |||
| 强制使用一致的逗号风格 | |||
| enforce consistent spacing inside computed property brackets | |||
| 强制在计算的属性的方括号中使用一致的空格 | |||
| enforce consistent naming when capturing the current execution context | |||
| 当获取当前执行环境的上下文时,强制使用一致的命名 | |||
| require or disallow newline at the end of files | |||
| 要求或禁止文件末尾存在空行 | |||
| require or disallow spacing between function identifiers and their invocations | |||
| 要求或禁止在函数标识符和其调用之间有空格 | |||
| require function names to match the name of the variable or property to which they are assigned | |||
| 要求函数名与赋值给它们的变量名或属性名相匹配 | |||
| require or disallow named  | |||
| 要求或禁止使用命名的  | |||
| enforce the consistent use of either  | |||
| 强制一致地使用  | |||
| enforce consistent line breaks inside function parentheses | |||
| 强制在函数括号内使用一致的换行 | |||
| disallow specified identifiers | |||
| 禁用指定的标识符 | |||
| enforce minimum and maximum identifier lengths | |||
| 强制标识符的最小和最大长度 | |||
| require identifiers to match a specified regular expression | |||
| 要求标识符匹配一个指定的正则表达式 | |||
| enforce the location of arrow function bodies | |||
| 强制隐式返回的箭头函数体的位置 | |||
| enforce consistent indentation | |||
| 强制使用一致的缩进 | |||
| enforce the consistent use of either double or single quotes in JSX attributes | |||
| 强制在 JSX 属性中一致地使用双引号或单引号 | |||
| enforce consistent spacing between keys and values in object literal properties | |||
| 强制在对象字面量的属性中键和值之间使用一致的间距 | |||
| enforce consistent spacing before and after keywords | |||
| 强制在关键字前后使用一致的空格 | |||
| enforce position of line comments | |||
| 强制行注释的位置 | |||
| enforce consistent linebreak style | |||
| 强制使用一致的换行风格 | |||
| require empty lines around comments | |||
| 要求在注释周围有空行 | |||
| require or disallow an empty line between class members | |||
| 要求或禁止类成员之间出现空行 | |||
| enforce a maximum depth that blocks can be nested | |||
| 强制可嵌套的块的最大深度 | |||
| enforce a maximum line length | |||
| 强制一行的最大长度 | |||
| enforce a maximum number of lines per file | |||
| 强制最大行数 | |||
| enforce a maximum number of line of code in a function | |||
| 强制函数最大代码行数 | |||
| enforce a maximum depth that callbacks can be nested | |||
| 强制回调函数最大嵌套深度 | |||
| enforce a maximum number of parameters in function definitions | |||
| 强制函数定义中最多允许的参数数量 | |||
| enforce a maximum number of statements allowed in function blocks | |||
| 强制函数块最多允许的的语句数量 | |||
| enforce a maximum number of statements allowed per line | |||
| 强制每一行中所允许的最大语句数量 | |||
| enforce a particular style for multiline comments | |||
| 强制对多行注释使用特定风格 | |||
| enforce newlines between operands of ternary expressions | |||
| 要求或禁止在三元操作数中间换行 | |||
| require constructor names to begin with a capital letter | |||
| 要求构造函数首字母大写 | |||
| enforce or disallow parentheses when invoking a constructor with no arguments | |||
| 强制或禁止调用无参构造函数时有圆括号 | |||
| require a newline after each call in a method chain | |||
| 要求方法链中每个调用都有一个换行符 | |||
| disallow  | |||
| 禁用  | |||
| disallow bitwise operators | |||
| 禁用按位运算符 | |||
| disallow  | |||
| 禁用  | |||
| disallow inline comments after code | |||
| 禁止在代码后使用内联注释 | |||
| disallow  | |||
| 禁止  | |||
| disallow mixed binary operators | |||
| 禁止混合使用不同的操作符 | |||
| disallow mixed spaces and tabs for indentation | |||
| 禁止空格和 tab 的混合缩进 | |||
| disallow use of chained assignment expressions | |||
| 禁止连续赋值 | |||
| disallow multiple empty lines | |||
| 禁止出现多行空行 | |||
| disallow negated conditions | |||
| 禁用否定的表达式 | |||
| disallow nested ternary expressions | |||
| 禁用嵌套的三元表达式 | |||
| disallow  | |||
| 禁用  | |||
| disallow the unary operators  | |||
| 禁用一元操作符  | |||
| disallow specified syntax | |||
| 禁用特定的语法 | |||
| disallow all tabs | |||
| 禁用 tab | |||
| disallow ternary operators | |||
| 禁用三元操作符 | |||
| disallow trailing whitespace at the end of lines | |||
| 禁用行尾空格 | |||
| disallow dangling underscores in identifiers | |||
| 禁止标识符中有悬空下划线 | |||
| disallow ternary operators when simpler alternatives exist | |||
| 禁止可以在有更简单的可替代的表达式时使用三元操作符 | |||
| disallow whitespace before properties | |||
| 禁止属性前有空白 | |||
| enforce the location of single-line statements | |||
| 强制单个语句的位置 | |||
| enforce consistent line breaks inside braces | |||
| 强制大括号内换行符的一致性 | |||
| enforce consistent spacing inside braces | |||
| 强制在大括号中使用一致的空格 | |||
| enforce placing object properties on separate lines | |||
| 强制将对象的属性放在不同的行上 | |||
| enforce variables to be declared either together or separately in functions | |||
| 强制函数中的变量要么一起声明要么分开声明 | |||
| require or disallow newlines around variable declarations | |||
| 要求或禁止在变量声明周围换行 | |||
| require or disallow assignment operator shorthand where possible | |||
| 要求或禁止在可能的情况下使用简化的赋值操作符 | |||
| enforce consistent linebreak style for operators | |||
| 强制操作符使用一致的换行符 | |||
| require or disallow padding within blocks | |||
| 要求或禁止块内填充 | |||
| require or disallow padding lines between statements | |||
| 要求或禁止在语句间填充空行 | |||
| disallow using Object.assign with an object literal as the first argument and prefer the use of object spread instead. | |||
| 禁止使用以对象字面量作为第一个参数的 Object.assign,优先使用对象扩展。 | |||
| require quotes around object literal property names | |||
| 要求对象字面量属性名称用引号括起来 | |||
| enforce the consistent use of either backticks, double, or single quotes | |||
| 强制使用一致的反勾号、双引号或单引号 | |||
| require or disallow semicolons instead of ASI | |||
| 要求或禁止使用分号代替 ASI | |||
| enforce consistent spacing before and after semicolons | |||
| 强制分号之前和之后使用一致的空格 | |||
| enforce location of semicolons | |||
| 强制分号的位置 | |||
| require object keys to be sorted | |||
| 要求对象属性按序排列 | |||
| require variables within the same declaration block to be sorted | |||
| 要求同一个声明块中的变量按顺序排列 | |||
| enforce consistent spacing before blocks | |||
| 强制在块之前使用一致的空格 | |||
| enforce consistent spacing before  | |||
| 强制在  | |||
| enforce consistent spacing inside parentheses | |||
| 强制在圆括号内使用一致的空格 | |||
| require spacing around infix operators | |||
| 要求操作符周围有空格 | |||
| enforce consistent spacing before or after unary operators | |||
| 强制在一元操作符前后使用一致的空格 | |||
| enforce consistent spacing after the  | |||
| 强制在注释中  | |||
| enforce spacing around colons of switch statements | |||
| 强制在 switch 的冒号左右有空格 | |||
| require or disallow spacing between template tags and their literals | |||
| 要求或禁止在模板标记和它们的字面量之间有空格 | |||
| require or disallow Unicode byte order mark (BOM) | |||
| 要求或禁止 Unicode 字节顺序标记 (BOM) | |||
| require parenthesis around regex literals | |||
| 要求正则表达式被括号括起来 | 
ECMAScript 6
These rules relate to ES6, also known as ES2015:
这些规则只与 ES6 有关, 即通常所说的 ES2015:
| require braces around arrow function bodies | |||
| 要求箭头函数体使用大括号 | |||
| require parentheses around arrow function arguments | |||
| 要求箭头函数的参数使用圆括号 | |||
| enforce consistent spacing before and after the arrow in arrow functions | |||
| 强制箭头函数的箭头前后使用一致的空格 | |||
| require  | |||
| 要求在构造函数中有  | |||
| enforce consistent spacing around  | |||
| 强制 generator 函数中  | |||
| disallow reassigning class members | |||
| 禁止修改类声明的变量 | |||
| disallow arrow functions where they could be confused with comparisons | |||
| 禁止在可能与比较操作符相混淆的地方使用箭头函数 | |||
| disallow reassigning  | |||
| 禁止修改  | |||
| disallow duplicate class members | |||
| 禁止类成员中出现重复的名称 | |||
| disallow duplicate module imports | |||
| 禁止重复模块导入 | |||
| disallow  | |||
| 禁止  | |||
| disallow specified modules when loaded by  | |||
| 禁止使用指定的  | |||
| disallow  | |||
| 禁止在构造函数中,在调用  | |||
| disallow unnecessary computed property keys in object literals | |||
| 禁止在对象中使用不必要的计算属性 | |||
| disallow unnecessary constructors | |||
| 禁用不必要的构造函数 | |||
| disallow renaming import, export, and destructured assignments to the same name | |||
| 禁止在 import 和 export 和解构赋值时将引用重命名为相同的名字 | |||
| require  | |||
| 要求使用  | |||
| require or disallow method and property shorthand syntax for object literals | |||
| 要求或禁止对象字面量中方法和属性使用简写语法 | |||
| require using arrow functions for callbacks | |||
| 要求回调函数使用箭头函数 | |||
| require  | |||
| 要求使用  | |||
| require destructuring from arrays and/or objects | |||
| 优先使用数组和对象解构 | |||
| disallow  | |||
| 禁用  | |||
| require rest parameters instead of  | |||
| 要求使用剩余参数而不是  | |||
| require spread operators instead of  | |||
| 要求使用扩展运算符而非  | |||
| require template literals instead of string concatenation | |||
| 要求使用模板字面量而非字符串连接 | |||
| require generator functions to contain  | |||
| 要求 generator 函数内有  | |||
| enforce spacing between rest and spread operators and their expressions | |||
| 强制剩余和扩展运算符及其表达式之间有空格 | |||
| enforce sorted import declarations within modules | |||
| 强制模块内的 import 排序 | |||
| require symbol descriptions | |||
| 要求 symbol 描述 | |||
| require or disallow spacing around embedded expressions of template strings | |||
| 要求或禁止模板字符串中的嵌入表达式周围空格的使用 | |||
| require or disallow spacing around the  | |||
| 强制在  | 
Deprecated
These rules have been deprecated in accordance with the deprecation policy, and replaced by newer rules:
| Deprecated rule | Replaced by | 
|---|---|
| (no replacement) | |
| (no replacement) | |
| (no replacement) | 
Removed
These rules from older versions of ESLint (before the deprecation policy existed) have been replaced by newer rules:
| Removed rule | Replaced by | 
|---|---|