enforce comparing typeof expressions against valid strings (valid-typeof)

强制 typeof 表达式与有效的字符串进行比较 (valid-typeof)

The "extends": "eslint:recommended" property in a configuration file enables this rule.

配置文件中的 "extends": "eslint:recommended" 属性启用了此规则。

For a vast majority of use cases, the result of the typeof operator is one of the following string literals: "undefined", "object", "boolean", "number", "string", "function", "symbol", and "bigint". It is usually a typing mistake to compare the result of a typeof operator to other string literals.

对于绝大多数用例而言，typeof 操作符的结果是以下字符串字面量中的一个："undefined"、"object"、"boolean"、"number"、"string"、"function"、"symbol" 和 "bigint"。把 typeof 操作符的结果与其它字符串进行比较，通常是个书写错误。

Rule Details

This rule enforces comparing typeof expressions to valid string literals.

该规则强制 typeof 表达式与有效的字符串进行比较。

Options

This rule has an object option:

该规则有一个对象选项：

Examples of incorrect code for this rule:

错误 代码示例：

/*eslint valid-typeof: "error"*/

typeof foo === "strnig"
typeof foo == "undefimed"
typeof bar != "nunber"
typeof bar !== "fucntion"

Examples of correct code for this rule:

正确 代码示例：

/*eslint valid-typeof: "error"*/

typeof foo === "string"
typeof bar == "undefined"
typeof foo === baz
typeof bar === typeof qux

Examples of incorrect code with the { "requireStringLiterals": true } option:

选项 { "requireStringLiterals": true } 的 错误 代码示例：

typeof foo === undefined
typeof bar == Object
typeof baz === "strnig"
typeof qux === "some invalid type"
typeof baz === anotherVariable
typeof foo == 5

Examples of correct code with the { "requireStringLiterals": true } option:

选项 { "requireStringLiterals": true } 的 正确 代码示例：

typeof foo === "undefined"
typeof bar == "object"
typeof baz === "string"
typeof bar === typeof qux

When Not To Use It

You may want to turn this rule off if you will be using the typeof operator on host objects.

如果你将在宿主对象上使用 typeof 操作符，你可以关闭此规则。

Further Reading

Version

This rule was introduced in ESLint 0.5.0.

该规则在 ESLint 0.5.0 中被引入。

Resources