How do I get my Azure DevOps Pipeline build to fail when my linting script returns an error?

Question

I am using the Azure Pipelines GitHub add-on to ensure that pull requests pass my linting. However, I have just made a test pull request which fails my linting, but the Azure Pipeline succeeds.

Here is my azure-pipelines.yml

# Node.js with React
# Build a Node.js project that uses React.
# Add steps that analyze code, save build artifacts, deploy, and more:
# https://docs.microsoft.com/azure/devops/pipelines/languages/javascript

trigger:
- master

pool:
  vmImage: 'Ubuntu-16.04'

steps:
- task: NodeTool@0
  inputs:
    versionSpec: '8.x'
  displayName: 'Install Node.js'

- script: |
    npm install
    npm run lint # Mapped to `eslint src` in package.json
    npm run slint # `stylelint src` in package.json
    npm run build
  displayName: 'npm install and build'

And here is (part of) the output on a branch which I know fails on npm run lint

> [email protected] lint /home/vsts/work/1/s
> eslint src


/home/vsts/work/1/s/src/js/components/CountryInput.js
  26:45  error  'onSubmit' is missing in props validation  react/prop-types
  27:71  error  'onSubmit' is missing in props validation  react/prop-types

✖ 2 problems (2 errors, 0 warnings)

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] lint: `eslint src`
npm ERR! Exit status 1 # Exit status 1, yet the build succeeds?
npm ERR! 
npm ERR! Failed at the [email protected] lint script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/vsts/.npm/_logs/2019-03-16T05_30_52_226Z-debug.log

> [email protected] slint /home/vsts/work/1/s
> stylelint src


> [email protected] build /home/vsts/work/1/s
> react-scripts build

Creating an optimized production build...
Compiled successfully.

# Truncated...

As you can see, linter runs nicely and catches my intentional error (I removed a prop type validation), and exits with code 1.

However the build just carries on its merry way.

What do I need to do to make such a linting error stop my build in its tracks and not return success?

Thank you in advance.

Answer 1

Neither approach above worked for my specific scenario (windows build agent, wanted to run a custom linting script, didn't want to use a script in package.json)

If you just throw an error from a node script, the pipeline treats it as a failed step.

pipelines yml:

  - script: 'node lint-my-stuff'
    displayName: 'Lint my stuff'

lint-my-stuff.js

// run eslint, custom checks, whatever

if (/* conditions aren't met */)
  throw new Error('Lint step failed')

console.log('Lint passed')

Answer 2

this means your script "swallows" the exit code and exits normally. you need to add a check to your script that would catch the exit code of your npm run lint and exit with the same exit code, something like:

- script: |
    npm install
    npm run lint # Mapped to `eslint src` in package.json
    if [ $? -ne 0 ]; then
        exit 1
    fi
    npm run slint # `stylelint src` in package.json
    npm run build