math/prefer-number-is-nan

enforce the use of Number.isNaN() instead of other checking ways

• ⚙️ This rule is included in "plugin:math/recommended".
• 🔧 The --fix option on the command line can automatically fix some of the problems reported by this rule.
• 💡 Some problems reported by this rule are manually fixable by editor suggestions.

📖 Rule Details

This rule aims to enforce the use of Number.isNaN() instead of other checking ways.

Number.isNaN() is the most reliable way to check for NaN values because:

• Type safety: Only returns true for actual NaN values, not for non-numeric types
• No type coercion: Unlike global isNaN(), it doesn't convert values to numbers first
• Clear intent: Explicitly shows you're checking for the NaN value
• Performance: Direct comparison without type conversion overhead
• Consistency: Part of the modern Number API alongside other type-checking methods

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🔧 Options

Nothing.

📚 Further reading

• MDN - Number.isNaN()

🚀 Version

This rule was introduced in eslint-plugin-math v0.4.0

🔍 Implementation

• Rule source
• Test source
• Test fixture sources