Rule proposal: Number(str) over parseFloat(str)
Description
In most cases, Number(string) produces better results than parseFloat(string):
Number.parseFloat("420") // 420
Number.parseFloat("-420") // -420
Number.parseFloat("420.69") // 420.69
Number.parseFloat("420,69") // 420 (NaN would have been better)
Number.parseFloat("420n") // 420 (NaN would have been better)
Number.parseFloat("420_69") // 420 (NaN or 42069 would have been better)
Number.parseFloat("0b1000101") // 0 (NaN or 69 would have been better)
Number.parseFloat("0x45") // 0 (NaN or 69 would have been better)
Number.parseFloat("") // NaN
Number.parseFloat(" \n") // NaNNumber("420") // 420
Number("-420") // -420
Number("420.69") // 420.69
Number("420,69") // NaN
Number("420n") // NaN
Number("420_69") // 42069
Number("0b1000101") // 69
Number("0x45") // 69
Number("") // 0 (NaN would have been better)
Number(" \n") // 0 (NaN would have been better)If you want to protect against those last two cases, it's a lot easier to do it with Number() than parseFloat():
function safeParseFloat(input: string) {
if (input.trim() === "") {
return Number.NaN
}
return Number(input)
}Fail
parseFloat(input)
Number.parseFloat(input)Pass
N/A
Additional Info
Here is a starting place for an eslint rule: https://astexplorer.net/#/gist/1569a1b6990fa03c94c76393b2ccc6a3/5e9b8eae2e48277a76e6f3680d1001b13e1d22c3
sindresorhus / eslint-plugin-unicorn
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