You can use this validator to validate your configuration without having to push a commit.
Run this command in your repository to validate your configuration:
nix eval --json --file ./nix-ci.nix | curl --netrc -H "Content-Type: application/json" -d @- https://nix-ci.com/documentation/configuration
Alternatively, you can run
nix eval --json --file ./nix-ci.nix
and paste the output below.