Is there a reliable method to identify and prevent NaN values during runtime, throughout all areas of the application where they might arise?
- A) Are there effective linting tools available to alert about possible occurrences of
NaNvalues within specific code constructs? - B) Alternatively, is there a solution that can monitor the execution of JavaScript at runtime, identify and log or notify about such instances? Similar to how error detection services operate?
Illustrative Scenario
An example scenario showcasing challenges in detecting NaN:
function undetectedNaN (): AssumeStrictDataTypes {
// 1. Algorithm implementation ...
// 2. Undetected appearance of NaN ...
// 3. Algorithm continuation ...
// 4. Return: Erroneous yet seemingly valid value and data type
}
(Assuming this issue exists within a larger codebase where incorporating checks for isNaN() and validating individual values is impractical: due to cost constraints, lack of necessity, absence of automated testing, etc.)
UPDATE 2021/12: To further elaborate on my abstract query: In a practical context, missing API values caused problems with a array structure. Most instances of NaN could be fixed by enhancing value/type validation.
function example (a, b) {
return a[0] + b[0]
}
// undefined + undefined = NaN
const result = example([], []);
console.log(result);
Additional cases where NaN may emerge:
const testArray = [];
const testObject = {};
testArray[0] + testArray[0] // NaN
testObject.X + testObject.X // NaN
undefined + undefined // NaN
NaN + NaN // NaN
Other scenarios where tracking NaN proves challenging:
e.g. its occurrence untraceable during runtime, sporadic appearances with no discernible pattern, and not a testable outcome.
// Bitwise operators
~(NaN) // -1
// Conditional statements
if (NaN > 1) {} // false
// Type conversion
!!NaN // false