How to store node script output into azure task variable

I am trying to store output of a node script into an azure task variable.

Came across this question Return a value from node.js script in azure pipeline? and based on this I have created a simple yml as below. But when I run this yml, script itself is not running, whereas If I run node test.js directly without setting task variable it is working fine and I can see the output. Not sure what am I doing wrong here, can anyone please point me in the right direction. Thanks

resources:
  repositories:
    - repository: "testRepo"
      type: git
      name: project/repo

trigger: none

stages:
  - stage: Test
    variables:
      Test_Result: ''
    jobs:
    - job: TestJob
      displayName: Test
      steps:

      - checkout: self
      - checkout: testRepo

      - script: |
          npm install
        workingDirectory: $(System.DefaultWorkingDirectory)\testrepo

      # Not working - script not running
      - script: |
          echo "##vso[task.setvariable variable=Test_Result]$(node test.js)"
        workingDirectory: $(System.DefaultWorkingDirectory)\testrepo

Output for above:

Output when node test.js is used without setting task variable

- script: |
     node test.js
  workingDirectory: $(System.DefaultWorkingDirectory)\tp-ui-caseMgmtV8