Jenkins – Required context class hudson.FilePath is missing Perhaps you forgot to surround the code with a step that provides this, such as: node

When i load another groovy file in Jenkinsfile it show me following error.

"Required context class hudson.FilePath is missing
Perhaps you forgot to surround the code with a step that provides this, such as: node"

I made a groovy file which contains a function and i want to call it in my Declarative Jenkinsfile. but it shows an error.

My Jenkinsfile--->
def myfun = load 'testfun.groovy'
pipeline{
    agent any
    environment{
        REPO_PATH='/home/manish/Desktop'
        APP_NAME='test'
    stages{
        stage('calling function'){
            steps{
                script{
                    myfun('${REPO_PATH}','${APP_NAME}')
Result–
org.jenkinsci.plugins.workflow.steps.MissingContextVariableException: Required context class hudson.FilePath is missing

Perhaps you forgot to surround the code with a step that provides this, such as: node
Suggest me what is the right way to do it.
You either need to use a scripted pipeline and put "load" instruction inside the node section (see this question) or if you are already using a declarative pipeline (which seems to be the case), you can include it in "environment" section:
environment {
    REPO_PATH='/home/manish/Desktop'
    APP_NAME='test'
    MY_FUN = load 'testfun.groovy'
Related Solutions
Jenkins – Use a lightweight executor for a declarative pipeline stage (agent none)

Setting agent none at the top level, then agent { label 'foo' } on every stage, with agent none again on the input stage seems to work as expected for me.
i.e. Every stage that does some work runs on the same agent, while the input stage does not consume an executor on any agent.
pipeline {
    agent none
    stages {
        stage("Prepare build") {
            agent { label 'some-agent' }
            steps {
                echo "prepare: ${pwd()}"
        stage("Build") {
            agent { label 'some-agent' }
            steps {
                parallel(
                    frontend: {
                        echo "frontend: ${pwd()}"
                    backend: {
                        echo "backend: ${pwd()}"
        stage("Test") {
            agent { label 'some-agent' }
            steps {
                parallel(
                    jslint: {
                        echo "jslint: ${pwd()}"
                    phpcs: {
                        echo "phpcs: ${pwd()}"
        stage("Select deploy target") {
            agent none
            steps {
                input message: 'Deploy?'
        stage("Deploy") {
            agent { label 'some-agent' }
            steps {
                echo "deploy: ${pwd()}"
However, there are no guarantee that using the same agent label within a Pipeline will always end up using the same workspace, e.g. as another build of the same job while the first build is waiting on the input.
You would have to use stash after the build steps.  As you note, this cannot be done normally with parallel at the moment, so you'd have to additionally use a script block, in order to write a snippet of Scripted Pipeline for the stashing/unstashing after/before the parallel steps.
    
Jenkins – How to run multiple stages on the same node with declarative Jenkins pipeline

Since version 1.3 of Declarative Pipeline plugin, this is officially supported.
It's officially called "Sequential Stages".
pipeline {
    agent none
    stages {
        stage("check code style") {
            agent {
                docker "code-style-check-image"
            steps {
                sh "./check-code-style.sh"
        stage("build and test the project") {
            agent {
                docker "build-tools-image"
            stages {
               stage("build") {
                   steps {
                       sh "./build.sh"
               stage("test") {
                   steps {
                       sh "./test.sh"
Official announcement here: https://jenkins.io/blog/2018/07/02/whats-new-declarative-piepline-13x-sequential-stages/