Infinite loop in interpolationSearch

Details:

Some entries might cause interpolationSearch to fall into an infinite loop.
Step to reproduce: interpolationSearch([0, 3], 6)

How did I find it?

Thanks to property based testing framework fast-check.
The property was the following:

import fc from 'fast-check';

fc.assert(
  fc.property(
    fc.array(fc.integer()).map(arr => [...arr].sort((a, b) => a - b)),
    fc.integer(),
    (arr, i) => expect(interpolationSearch(arr, i)).toBe(arr.indexOf(i))
  )
)

Or:

for any arr - sorted array of integers - and i - integer value
interpolationSearch(arr, i) should be equivalent to arr.indexOf(i)

Locate the interpolationSearch entry point and reproduce the reported case, interpolationSearch([0, 3], 6). Then run or extend the relevant tests with the stated sorted-array property; done means searches terminate and return the same result as arr.indexOf(i).