Use `repositoryCustomPropertyValues` GraphQL field to populate CustomProperties on GitHubRepository

[MariusStorhaug]

Summary

GitHub's GraphQL API now exposes custom properties directly on the Repository type via the repositoryCustomPropertyValues connection field. This means Get-GitHubRepository can return custom properties inline — eliminating the need for a separate REST call via Get-GitHubRepositoryCustomProperty.

Current behavior

• Get-GitHubRepository uses GraphQL to fetch repositories, but CustomProperties is always $null because the PropertyToGraphQLMap maps CustomProperties to '' (empty string) and the GraphQL constructor never populates it.
• To get custom properties, users must make a separate call: Get-GitHubRepositoryCustomProperty -Owner <owner> -Repository <repo>, which uses the REST endpoint GET /repos/{owner}/{repo}/properties/values.

GraphQL schema discovery

Schema introspection confirms two fields on the Repository type:

Field	Type	Description
repositoryCustomPropertyValue	RepositoryCustomPropertyValue	A single custom property value
repositoryCustomPropertyValues	RepositoryCustomPropertyValueConnection	A paginated list of custom property values

The connection node type RepositoryCustomPropertyValue has:

• propertyName (String!)
• value (String!)

Example query

{
  repository(owner: "PSModule", name: "GitHub") {
    repositoryCustomPropertyValues(first: 100) {
      nodes {
        propertyName
        value
      }
    }
  }
}

Returns:

{
  "propertyName": "Type",
  "value": "Module"
}

Proposed changes

1. GitHubRepository.PropertyToGraphQLMap — Update the CustomProperties entry from '' to:

   'repositoryCustomPropertyValues(first: 100) { nodes { propertyName value } }'
   

2. GitHubRepository GraphQL constructor — Add logic to populate $this.CustomProperties from the GraphQL response, converting the nodes array into the same shape as the REST API returns (or a suitable hashtable/PSCustomObject).

3. Consider whether Get-GitHubRepositoryCustomProperty should remain as a standalone function for cases where users only need custom properties without fetching the full repository object (it may still be useful).

References

• Confirmed via live GraphQL schema introspection (__type query) — February 2026
• GitHub GraphQL Explorer: https://docs.github.com/en/graphql/overview/explorer
• GitHub GraphQL Changelog: https://docs.github.com/en/graphql/overview/changelog