[polaris-react] Storybook build fails on class based components with static properties

[kyledurand]

Issue summary

Seeing a bunch of these in terminal when running yarn dev in the polaris-react folder. Storybook or babel doesn't know how to transform static properties

This issue began after #6852 shipped. I think it's related to yarn.lockchanges in that PR

ModuleBuildError: Module build failed (from ../node_modules/babel-loader/lib/index.js):
SyntaxError: /Users/kyledurand/Shopify/polaris/polaris-react/src/utilities/unique-id/unique-id-factory.ts: Missing class properties transform.
  3 |
  4 | export class UniqueIdFactory {
> 5 |   private idGeneratorFactory: IdGeneratorFactory;
    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  6 |
  7 |   private idGenerators: {[key: string]: IdGenerator} = {};
  8 |
    at File.buildCodeFrameError (/Users/kyledurand/Shopify/polaris/node_modules/@babel/core/lib/transformation/file/file.js:249:12)
    at NodePath.buildCodeFrameError (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/path/index.js:143:21)
    at pushBody (/Users/kyledurand/Shopify/polaris/node_modules/@babel/plugin-transform-classes/lib/transformClass.js:143:20)
    at buildBody (/Users/kyledurand/Shopify/polaris/node_modules/@babel/plugin-transform-classes/lib/transformClass.js:117:5)
    at classTransformer (/Users/kyledurand/Shopify/polaris/node_modules/@babel/plugin-transform-classes/lib/transformClass.js:577:5)
    at transformClass (/Users/kyledurand/Shopify/polaris/node_modules/@babel/plugin-transform-classes/lib/transformClass.js:621:10)
    at PluginPass.ClassExpression (/Users/kyledurand/Shopify/polaris/node_modules/@babel/plugin-transform-classes/lib/index.js:67:54)
    at newFn (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/visitors.js:177:21)
    at NodePath._call (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/path/context.js:53:20)
    at NodePath.call (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/path/context.js:40:17)
    at NodePath.visit (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/path/context.js:100:31)
    at TraversalContext.visitQueue (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/context.js:105:16)
    at TraversalContext.visitSingle (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/context.js:79:19)
    at TraversalContext.visit (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/context.js:133:19)
    at traverseNode (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/traverse-node.js:24:17)
    at NodePath.visit (/Users/kyledurand/Shopify/polaris/node_modules/@babel/traverse/lib/path/context.js:107:52)
    at processResult (/Users/kyledurand/Shopify/polaris/node_modules/@storybook/builder-webpack5/node_modules/webpack/lib/NormalModule.js:758:19)
    at /Users/kyledurand/Shopify/polaris/node_modules/@storybook/builder-webpack5/node_modules/webpack/lib/NormalModule.js:860:5
    at /Users/kyledurand/Shopify/polaris/node_modules/loader-runner/lib/LoaderRunner.js:400:11
    at /Users/kyledurand/Shopify/polaris/node_modules/loader-runner/lib/LoaderRunner.js:252:18
    at context.callback (/Users/kyledurand/Shopify/polaris/node_modules/loader-runner/lib/LoaderRunner.js:124:13)
    at /Users/kyledurand/Shopify/polaris/node_modules/babel-loader/lib/index.js:59:103

[kyledurand]

Fixed with 48daff4