Incorrect validation on github_repository.topic field

[danielpops]

Terraform Version

0.13.7

Affected Resource(s)

Please list the resources as a list, for example:

• github_repository

The regex validation on the topic field does not work for single-character topics (e.g. the letter "a" or "c")

Terraform Configuration Files

resource "github_repository" "repo" {
  name        = "Test" 
  description = "Single Letter topics will fail"

  topics = [
    "a"
  ]

Expected Behavior

Plan should succeed

Actual Behavior

Plan fails, with error:

Error: invalid value for topics.0 (must include only lowercase alphanumeric characters or hyphens and cannot start with a hyphen and consist of 35 characters or less)

Steps to Reproduce

Please list the steps required to reproduce the issue, for example:

1. terraform plan

https://regex101.com/r/vdLOLS/2

[danielpops]

Fixed by #996