After upgrading to React-Native 0.56.0 metro build fails (TypeError: Cannot read property 'ast' of null)

[djschilling]

• Review the documentation: https://facebook.github.io/react-native
• Search for existing issues: https://github.com/facebook/react-native/issues
• Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

Run react-native info in your terminal and paste its contents here.

 React Native Environment Info:
 System:
 OS: macOS High Sierra 10.13.5
 CPU: x64 Intel(R) Core(TM) i5-5287U CPU @ 2.90GHz
 Memory: 45.86 MB / 8.00 GB
 Shell: 3.2.57 - /bin/bash
 Binaries:
 Node: 8.11.3 - ~/.nvm/versions/node/v8.11.3/bin/node
 Yarn: 1.7.0 - /usr/local/bin/yarn
 npm: 5.6.0 - ~/.nvm/versions/node/v8.11.3/bin/npm
 Watchman: 4.9.0 - /usr/local/bin/watchman
 SDKs:
 iOS SDK:
 Platforms: iOS 11.4, macOS 10.13, tvOS 11.4, watchOS 4.3
 Android SDK:
 Build Tools: 23.0.1, 25.0.1, 26.0.2, 27.0.3, 28.0.0
 API Levels: 23, 25, 26, 27
 IDEs:
 Android Studio: 3.1 AI-173.4819257
 Xcode: 9.4/9F1027a - /usr/bin/xcodebuild
 npmPackages:
 react: 16.4.1 => 16.4.1
 react-native: 0.56.0 => 0.56.0
 npmGlobalPackages:
 react-native-cli: 2.0.1

Description

After upgrading to react-native version 0.56.0 my metro build fails with the error message TypeError: Cannot read property 'ast' of null.
I also read this issue #19827 but could not fix my issue with the suggestions there.

From the error message it seams the bug is in the metro src.

Detailed error message:

error: bundling failed: TypeError: Cannot read property 'ast' of null
 at Object.transform (/Users/david/projects/churchtools-mobile/node_modules/metro/src/reactNativeTransformer.js:167:48)
 at Object.<anonymous> (/Users/david/projects/churchtools-mobile/node_modules/metro/src/JSTransformer/worker.js:204:23)
 at Generator.next (<anonymous>)
 at step (/Users/david/projects/churchtools-mobile/node_modules/metro/src/JSTransformer/worker.js:328:291)
 at /Users/david/projects/churchtools-mobile/node_modules/metro/src/JSTransformer/worker.js:328:521
 at new Promise (<anonymous>)
 at Object.<anonymous> (/Users/david/projects/churchtools-mobile/node_modules/metro/src/JSTransformer/worker.js:328:202)
 at Object.transformCode [as transform] (/Users/david/projects/churchtools-mobile/node_modules/metro/src/JSTransformer/worker.js:292:93)
 at execMethod (/Users/david/projects/churchtools-mobile/node_modules/jest-worker/build/child.js:90:29)

[ptmt]

Do you have ignore section in your .babelrc by any chance? It doesn't work for me well (config gets unresolved, and babel transformation fails), so I removed this section for now. Probably also need to test with newer babel / metro and file an issue.

[helenaford]

Wish there was a solution for this. Ignore was working for me before I upgraded my babel from beta.47 to 7.0.0. Issue is with React-Native 0.57.0 too.

[jkimbo]

This looks like a bug in metro. I found a patch that fixes it: react/metro#255 (comment)

[stale]

Hey there, it looks like there has been no activity on this issue recently. Has the issue been fixed, or does it still require the community's attention? This issue may be closed if no further activity occurs. You may also label this issue as "For Discussion" or "Good first issue" and I will leave it open. Thank you for your contributions.