plugin-postcss extendConfig option is broken with PostCSS error

[thescientist13]

Type of Change

• New Feature Request
• Documentation / Website
• Improvement / Suggestion
• Bug
• Other (please clarify below)

Summary

When trying to use the extendConfig option, the command fails with this error

Error: postcss-preset-env is not a PostCSS plugin
    at Processor.normalize (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/node_modules/postcss/lib/processor.js:169:15)
    at new Processor (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/node_modules/postcss/lib/processor.js:56:25)
    at postcss (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/node_modules/postcss/lib/postcss.js:55:10)
    at PostCssResource.optimize (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/packages/plugin-postcss/src/index.js:5:2991)
    at /Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/packages/cli/src/config/rollup.config.js:2:1270
    at async getOptimizedSource (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/packages/cli/src/config/rollup.config.js:2:937)
    at async Object.writeBundle (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/packages/cli/src/config/rollup.config.js:67:378)
    at async Promise.all (index 0)
    at async handleGenerateWrite (/Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/node_modules/rollup/dist/shared/rollup.js:23409:9)
    at async /Users/owenbuckley/Workspace/project-evergreen/repos/greenwood/packages/cli/src/lifecycles/bundle.js:2:233 {
  code: 'PLUGIN_ERROR',
  plugin: 'greenwood-html-plugin',
  hook: 'writeBundle'
}

Details

Ooof... looks like this isn't even getting set in the test, so that explains how it went undetected 🤦