Pattern string sampler does not take into account minLength property

[ostridm]

Description

Pattern string sampler does not take into account the minLength property and produce an unexpected error while string is being sampled.

Steps to reproduce

Pass the schema to sample as follows:

sample({
  type: 'string',
  format: 'pattern',
  maxLength: 4,
  minLength: 4,
  pattern: '^[0-9]+$'});

Actual result

Error reported:

Sample string cannot be generated by boundaries: minLength=4, maxLength=4, format=pattern

Expected result

Sample value generated successfully

   4444