Unity Shadergraph custom function node for main light data

MainLightNode.hlsl

#ifndef MAINLIGHT_INCLUDED
#define MAINLIGHT_INCLUDED

void GetMainLightData_float(out half3 direction, out half3 color, out half distanceAttenuation, out half shadowAttenuation)
{
#ifdef SHADERGRAPH_PREVIEW
    // In Shader Graph Preview we will assume a default light direction and white color
    direction = half3(-0.3, -0.8, 0.6);
    color = half3(1, 1, 1);
    distanceAttenuation = 1.0;
    shadowAttenuation = 1.0;
#else

    // Universal Render Pipeline
    #if defined(UNIVERSAL_LIGHTING_INCLUDED)
    
        // GetMainLight defined in Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl
        Light mainLight = GetMainLight();
        direction = -mainLight.direction;
        color = mainLight.color;
        distanceAttenuation = mainLight.distanceAttenuation;
        shadowAttenuation = mainLight.shadowAttenuation;
    
    #elif defined(HD_LIGHTING_INCLUDED) 
        // ToDo: make it work for HDRP (check define above)
        // Packages/com.unity.render-pipelines.high-definition/Runtime/Lighting/LightDefinition.cs.hlsl
        // if (_DirectionalLightCount > 0)
        // {
        //     DirectionalLightData light = _DirectionalLightDatas[0];
        //     lightDir = -light.forward.xyz;
        //     color = light.color;
        //     ......
        
    #endif

#endif
}

#endif

Super useful!