You can use block (/***/) or single line comment (//) for each line. You should use "#" in sh command.
Block comment
/* _x000D_
post {_x000D_
success {_x000D_
mail to: "[email protected]", _x000D_
subject:"SUCCESS: ${currentBuild.fullDisplayName}", _x000D_
body: "Yay, we passed."_x000D_
}_x000D_
failure {_x000D_
mail to: "[email protected]", _x000D_
subject:"FAILURE: ${currentBuild.fullDisplayName}", _x000D_
body: "Boo, we failed."_x000D_
}_x000D_
}_x000D_
*/
_x000D_
Single Line
// post {_x000D_
// success {_x000D_
// mail to: "[email protected]", _x000D_
// subject:"SUCCESS: ${currentBuild.fullDisplayName}", _x000D_
// body: "Yay, we passed."_x000D_
// }_x000D_
// failure {_x000D_
// mail to: "[email protected]", _x000D_
// subject:"FAILURE: ${currentBuild.fullDisplayName}", _x000D_
// body: "Boo, we failed."_x000D_
// }_x000D_
// }
_x000D_
Comment in 'sh' command
stage('Unit Test') {_x000D_
steps {_x000D_
ansiColor('xterm'){_x000D_
sh '''_x000D_
npm test_x000D_
# this is a comment in sh_x000D_
'''_x000D_
}_x000D_
}_x000D_
}
_x000D_