Utilities.formatToPrecision has wrong output for scientific notation

[JeneaVranceanu]

What happened?

Calling Utilities.formatToPrecision(..., fallbackToScientific: true) outputs a wrong value for some inputs.

What are the steps to reproduce?

let balance = BigInt("100000000000000000000")
let formatted = Utilities.formatToPrecision(balance, units: .ether, decimalSeparator: ",", fallbackToScientific: true)

What is the expected behavior?

Value in formatted from the example above should be 1e20 but it's 0e-18 instead.

What is the error thrown?

What's the stack trace said?

OS version

Library version

3.1.1

[JeneaVranceanu]

To resolve that I suggest the following:

• separate formatToPrecision into formatToPrecision and formatToScientificNotation;
• formatToScientificNotation must have a flag useNormalNotation. Normal notation in a scientific number means we have 1 digit that is between in range [1,9] that is to the left side of the separator.
• setting useNormalNotation to false will consider the formattingDecimals value that we have now. useNormalNotation set to true will ignore formattingDecimals.