InputSystemExtension.cs

#if UNITY_EDITOR

using UnityEditor;
using UnityEngine;

public static class InputSystemExtension
{
    public static bool CheckForInputSystemAsset()
    {
        bool inputSystemAssetFound;
        string[] assets = AssetDatabase.FindAssets("t:ScriptableObject InputSettings");

        if (assets.Length > 0)
        {
            inputSystemAssetFound = true;
            Debug.Log("Input System Asset found.");
        }
        else
        {
            inputSystemAssetFound = false;
            Debug.Log("No Input System Assets found.");
        }

        return inputSystemAssetFound;
    }

    public static bool CheckForInputSystem()
    {
        var inputSystemPackageInstalled = false;
        var inputSystemPackage = UnityEditor.PackageManager.PackageInfo.GetAllRegisteredPackages();
        var length = inputSystemPackage.Length;

        for (int i = 0; i < length; i++)
        {
            if (inputSystemPackage[i].name == "com.unity.inputsystem")
            {
                inputSystemPackageInstalled = true;
            }
        }

        if (inputSystemPackageInstalled) { Debug.Log("Input System package is installed"); }
        else { Debug.Log("Input System package is not installed"); }

        return inputSystemPackageInstalled;
    }
}

#endif