1. Vulnerability Description

• Comparing values in the form of FloatingPointType to == or != may result in different comparison results due to error.

2. Vulnerability Countermeasure

• Comparison should be made considering Precision.

3. Sample Code

• Vulnerable Code

scala> val a = 0.3
a: Double = 0.3

scala> val b = 0.1 + 0.2
b: Double = 0.30000000000000004

scala> a == b
res4: Boolean = false

• Safe Code

def ~=(x: Double, y: Double, precision: Double) = {
  if ((x - y).abs < precision) true else false
}

scala> val a = 0.3
a: Double = 0.3

scala> val b = 0.1 + 0.2
b: Double = 0.30000000000000004

scala> ~=(a, b, 0.0001)
res0: Boolean = true