Break down jenkins file steps

Jenkinsfile

     stage('Install npm packages') {
       steps {
       ansiColor('xterm') {
-        sh '''#!/bin/bash -ex
-        source ~/.bashrc
-        npm install
-        npm run clean'''
+        sh 'source ~/.bashrc'
         }
+        sh 'npm install'
+        sh 'npm run clean'
       }
     }
     stage('Run All Tests') {
       parallel {
         stage('Run test-js') {
           steps {
-            sh '''#!/bin/bash
-            source ~/.bashrc
-            npm run test-js'''
+            sh 'source ~/.bashrc'
+            sh 'npm run test-js'
           }
         }
         stage('Run IOS tests') {
           steps {
-            sh '''#!/bin/bash
-            source ~/.bashrc
-            npm run test-unit-ios -- --release
-            npm run test-e2e-ios -- --release'''
+            sh 'source ~/.bashrc'
+            ansiColor('xterm') {
+              sh 'npm run test-unit-ios -- --release'
+            }
+            sh 'npm run test-e2e-ios -- --release'
           }
         }
         stage('Run android tests') {
           steps {
-            sh '''#!/bin/bash
-            source ~/.bashrc
-            npm run test-unit-android -- --release
-            npm run test-e2e-android -- --release'''
+            sh 'source ~/.bashrc'
+            sh 'npm run test-unit-android -- --release'
+            sh 'npm run test-e2e-android -- --release'
           }
         }
       }