Number.isSafeInteger(value) checks whether value is a JavaScript number that is an exactly representable integer between -9,007,199,254,740,991 and 9,007,199,254,740,991. Values beyond this range can look valid while becoming indistinguishable from nearby integers. section 2.2.1
Checking a boundary value
Number.isSafeInteger(42) returns true. Number.isSafeInteger(Number.MAX_SAFE_INTEGER + 1) returns false, identifying a value outside the reliable integer range. section 2.2.1
The method accepts only values of type number. When code may receive both number and bigint values, check the type first and compare bigint values with BigInt(Number.MIN_SAFE_INTEGER) and BigInt(Number.MAX_SAFE_INTEGER). section 2.8
