Currently, users can pass in invalid input into Double constructor, and the inputs will be coerced to a value regardless of if the input is valid.

This subtask will create a Double.fromString helper that will validate input for these classes and throw on inputs that are not representable as a Double.

In V7, we will add these helpers to the Double constructor when a string input is passed in, so the numeric conversion will only happen after validation.

 Use Case

As a... BSON Double Class user
I want... my string inputs to throw when they will lose precision
So that... the value stored in the Double instance is the desired value

Acceptance Criteria

Implementation Requirements

• General Approach
  • Remove leading zeros in comparison
  • Don't allow whitespace (decimal 128 precedent)
  • Only allow decimal input
•  Error Cases
  • Don't allow non-decimal inputs (if string contains, a 'x' 'c' 'b')
  • Empty string
  • Number(value) === NaN but value is not 'NaN'
    • (something other than a NaN is coerced to a NaN)
  • !Number.isFinite(+value) but value is not 'Infinity' or '-Infinity'
• If not error case, return Number(value)

Testing Requirements

• Double Cases
  • Success Cases:
    • 'NaN', 'Infinity', '-Infinity', 0, -0
    •  Fraction
    • Basic test case for decimal
    • whitespace leading, trailing
    • leading zeros
  • Error Cases:
    • 'foo'
    •  ex: '2e308' (coerced to Infinity by Number(), but is not actually infinity'
    • Non-decimal inputs

Documentation Requirements

• add API docs for Double.fromString

Follow Up Requirements

• file v7 ticket (in subtasks)