valid-typeof.md

规则名	规则类型	深入了解
valid-typeof	problem	https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof

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.

规则详解

This rule enforces comparing typeof expressions to valid string literals.

配置项

This rule has an object option:

• "requireStringLiterals": true requires typeof expressions to only be compared to string literals or other typeof expressions, and disallows comparisons to any other value.

此规则的 错误 代码实例：

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

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

此规则的 正确 代码实例：

::: correct

/*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:

/*eslint valid-typeof: ["error", { "requireStringLiterals": true }]*/

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:

::: correct

/*eslint valid-typeof: ["error", { "requireStringLiterals": true }]*/

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

禁用建议

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