Storybook with CRA TS generates Cannot read property 'start' of undefined WARN at handleExportedName

Describe the bug Unable to run and build storybook 6 for typescript (tried with CRA and my own project setup without bundler).

All default stories except of Introduction.stories.mdx producing stack traces like:

WARN ./src/stories/Button.stories.tsx
WARN Module build failed (from ./node_modules/@storybook/source-loader/dist/index.js):
WARN TypeError: Cannot read property 'start' of undefined
WARN     at handleExportedName (/home/guria/ws/sandbox/my-app/node_modules/@storybook/source-loader/dist/abstract-syntax-tree/parse-helpers.js:130:19)
WARN     at Controller.enter (/home/guria/ws/sandbox/my-app/node_modules/@storybook/source-loader/dist/abstract-syntax-tree/traverse-helpers.js:161:58)

To Reproduce Steps to reproduce the behavior:

1. Init new project with yarn create react-app . --template typescript
2. Init storybook with npx sb init
3. Run yarn storybook-build

Expected behavior Storybook to be built without exceptions and warnings with stories for default components.

System: Please paste the results of npx sb@next info here.

Environment Info:

  System:
    OS: Linux 5.4 Ubuntu 20.04.1 LTS (Focal Fossa)
    CPU: (8) x64 Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
  Binaries:
    Node: 14.1.0 - ~/.nvm/versions/node/v14.1.0/bin/node
    Yarn: 1.22.4 - ~/.nvm/versions/node/v14.1.0/bin/yarn
    npm: 6.14.4 - ~/.nvm/versions/node/v14.1.0/bin/npm
  Browsers:
    Chrome: 84.0.4147.135
    Firefox: 79.0
  npmPackages:
    @storybook/addon-actions: ^6.0.16 => 6.0.16 
    @storybook/addon-essentials: ^6.0.16 => 6.0.16 
    @storybook/addon-links: ^6.0.16 => 6.0.16 
    @storybook/node-logger: ^6.0.16 => 6.0.16 
    @storybook/preset-create-react-app: ^3.1.4 => 3.1.4 
    @storybook/react: ^6.0.16 => 6.0.16 

Reproduction repo

See also repro repo and log from GitHub Actions run

Updates. Workarounds found.

Make sure prettier@2.1.0 is not in your node_modules. For yarn users https://github.com/storybookjs/storybook/issues/12217#issuecomment-679266729 For npm users https://github.com/storybookjs/storybook/issues/12217#issuecomment-679299790

So the root cause seems to be related to prettier@2.1.0 release happened today. We still need to track back what exactly lead to this error. See also https://github.com/prettier/prettier/issues/9039

[shilman]

Zoinks!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.0.17 containing PR #12226 that references this issue. Upgrade today to try it out!

[Guria]

I found. It is prettier@2.1.0 Temp workaround with yarn:

  // package.json
  "resolutions": {
    "prettier": "~2.0.0"
  }