# valid-typeof

Enforce the use of valid string literals in a typeof comparison.

typeof can only return a small set of strings, undefined, object, boolean, number, string or function, and if you provide an invalid value, it's most likely a typo, and the comparison will always return false. This behaviour will be denied by this rule.

# Invalid Code Examples

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

# Config

Name Type Description
requireStringLiterals bool * If this option is true, typeof expression can only be compared
* to valid string literals, or other typeof expressions, but
* can not be compared to any other value.
More incorrect examples
typeof foo === "strnig"
typeof foo == "undefimed"
typeof bar != "nunber"
typeof bar !== "fucntion"
More correct examples
typeof foo === "string"
typeof bar == "undefined"
typeof foo === baz
typeof foo === 4
typeof bar === typeof qux

Source (opens new window)

Last Updated: 11/18/2020, 9:36:33 PM