How to read environment variables in Script step in Azure DevOps?

Question

I am trying to run this command in Azure DevOps Build pipeline:

npm run coverage

This command requires 2 env variables available in order to complete successfully.

Earlier, I was using the NPM Task for the same but there is no way we can pass env variables in that task.

  - task: Npm@1
    displayName: npm test
    inputs:
      command: custom
      workingDir: $(Build.SourcesDirectory)
      verbose: false
      customCommand: run coverage

So I have changed it to Script step like following:

        - script: 'npm run coverage'
          workingDirectory: $(Build.SourcesDirectory)
          displayName: 'npm test'
          env:
            CLASS_PATH: './test/mock/'
            MONGO_PATH: '../../../services/mock/'

But it's not picking up these 2 env variables and the task is failing making the entire build fail.

I have also tried adding a Script task which sets these 2 env variables prior to run coverage command like following:

          - script: |
            export CLASS_PATH='./test/mock/'
            export MONGO_PATH='../../../services/mock/'
            echo $CLASS_PATH
            echo $MONGO_PATH

It prints the set env variables, but the next step which is npm run coverage is not getting those env variables.

Can anyone please help passing these env variables to the npm command?

My Pipeline:

trigger:
branches:
  include:
    - 'master'

variables:
  class_path: './test/mock/'
  mongo_path: '../../../services/mock/'  

pool: 'self-hosted'

stages:
  - stage: Build
    displayName: Build and push stage
    jobs:
      - job: Build
        displayName: Build
        pool:
          name: 'self-hosted'
        steps:

          - script: |
              export CLASS_PATH='./test/mock/'
              export MONGO_PATH='../../../services/mock/'
              echo $CLASS_PATH
              echo $MONGO_PATH

          - script: 'npm run coverage'
            workingDirectory: $(Build.SourcesDirectory)
            displayName: 'npm test'
            env:
              CLASS_PATH: $(class_path)
              MONGO_PATH: $(mongo_path)

score 0 · Answer 1 · answered Sep 27 '22 at 15:06

In Azure Devops a pipeline variable is presented as environment variable also.

For the next example previous variable will be available as $(class.path) and also as $CLASS_PATH

variables:
- name: class.path
  value: '/some/path'

steps:
  - task: Npm@1
    displayName: npm test
    inputs:
      command: custom
      workingDir: $(Build.SourcesDirectory)
      verbose: false
      customCommand: run coverage

Now it can happen some tasks will not pick up variables properly, being that case you can use like this:

variables:
- name: class.path
  value: '/some/path'
- name: mongo.path
  value: '/some/path'

steps:
    - script: 'npm run coverage'
      workingDirectory: $(Build.SourcesDirectory)
      displayName: 'npm test'
      env:
        CLASS_PATH: $(class.path)
        MONGO_PATH: $(mongo.path)

Note: The script task usually does not require explicit environment variable mapping, as it has immediate access to variables as environment variables.

The next step is checking your npm script, it might be getting variables properly.

Please have a look at this question to solve npm specifics regarding environment variables Passing environment variables in npm-scripts.

How to read environment variables in Script step in Azure DevOps?

1 Answers1