Azure Pipeline中使用Yarn替代Npm的配置问题求助

问题原因分析 #

• Unknown command: "yarn"：你用Npm@1任务的customCommand执行yarn命令，相当于在npm的运行上下文里调用yarn，自然找不到该命令——npm进程无法识别yarn指令。
• npm ERR! File exists: /opt/hostedtoolcache/node/18.19.1/x64/bin/yarnpkg：Azure托管代理的Node.js 18.x环境已经预装了yarn相关文件，重复全局安装会触发文件冲突。

解决方案 #

方案1：利用Node.js自带Corepack启用yarn（推荐） #

Node.js 16.10+自带Corepack工具，可直接启用yarn，无需手动全局安装。修改后的完整流水线配置如下：

steps:
- task: UseNode@1
  displayName: 'Install Node.js'
  inputs:
    version: '18.x'

# 启用Corepack自动管理yarn版本
- script: corepack enable
  displayName: 'Enable Corepack for yarn'

# 直接用Script任务执行yarn install，替代原Npm@1任务
- script: yarn install
  displayName: 'yarn install'
  workingDirectory: '$(Build.SourcesDirectory)/MyModule'

# Npm task can't publish pre-release therefore edit the package.json
# $(Build.BuildNumber) is actually the pipeline name set on the first line -- that's Azure YML for you.
- ${{ if not(or(eq(variables['Build.SourceBranchName'], 'master'), eq(variables['Build.SourceBranchName'], 'main'))) }}:
  - task: Npm@1
    displayName: 'npm version' 
    inputs:
      workingDir: '$(Build.SourcesDirectory)/MyModule'
      command: custom
      customCommand: version prerelease --preid=$(Build.BuildNumber)

# 用Script任务执行yarn build
- script: yarn run build
  displayName: 'yarn run build'
  workingDirectory: '$(Build.SourcesDirectory)/MyModule'
  
- task: CopyFiles@2
  inputs:
    sourceFolder: '$(Build.SourcesDirectory)'
    contents: |
       ReactWebsites/*
    targetFolder: '$(Build.ArtifactStagingDirectory)'
  displayName: 'Copy project files (MyModule/*)'

- task: Npm@1
  displayName: 'npm publish' 
  inputs:
    workingDir: '$(Build.SourcesDirectory)/MyModule'
    command: publish
    publishRegistry: useFeed
    publishFeed: 'MySoftware' 

方案2：使用官方Yarn任务 #

Azure DevOps提供了专门的Yarn任务，可直接替换原Npm@1执行yarn命令的步骤：

# 替换yarn install步骤
- task: YarnInstall@1
  displayName: 'yarn install'
  inputs:
    workingDir: '$(Build.SourcesDirectory)/MyModule'

# 替换yarn build步骤
- task: Yarn@1
  displayName: 'yarn run build'
  inputs:
    workingDir: '$(Build.SourcesDirectory)/MyModule'
    command: 'run'
    arguments: 'build'

方案3：强制覆盖全局安装yarn（不推荐） #

如果一定要通过npm全局安装，添加--force参数跳过文件冲突：

- script: npm install --global yarn --force
  displayName: 'Install yarn globally'

内容的提问来源于stack exchange，提问作者Richard Barraclough