TypeError: null is not an object (evaluating 'ReactNativeBlobUtil.DocumentDir')

[loupmasneri]

I am using react-native-blob-util because rn-fetch-blob has not been updated since 5 years ago and I have this error which happens with rn-fetch-blob too:

TypeError: null is not an object (evaluating 'ReactNativeBlobUtil.DocumentDir')

I am using react-native 0.68.1 and this only happened on android and not iOS.

If someone has already faced the issue.

"react-native": "0.68.1",
"react-native-blob-util": "^0.16.0",

[filiptdz]

I'm also seeing this issue. Strangely, the problem only happens when I run react-native run-android for an emulator, but install the resulting build to another. Installing to the initial emulator works fine.

[rusty120]

I encountered this as well. It looks like auto linking isn't configured properly for android. I believe to fix this, react and react-native need to be added as dev and peer dependencies to this project. Something like this:

    "devDependencies": {
        ...
        "react": "16.13.1",
        "react-native": "^0.68.2"
    },
    "peerDependencies": {
        "react": "*",
        "react-native": "*"
    }

To work around this before it's fixed, you can configure manually linking. Of course, those instructions aren't quite right either. They reference the old class and package names. Rename :react-native-fetch-blob to :react-native-blob-util and com.RNFetchBlob.RNFetchBlobPackage to com.ReactNativeBlobUtil.ReactNativeBlobUtilPackage and you should be good.

[filiptdz]

fyi the repo I'm working on has an unconventional setup, but I fixed this issue by running react-native bundle

[rusty120]

Oh, I suspect it may also work if you have react-native installed globally. That may be why more people haven't been tripped up by this?

[filiptdz]

Could be, I use npx react-native instead of installing it globally

[RonRadtke]

Can you confirm it's working with the peerDependencies? @rusty120 @filiptdz
Porlbme is I wasn't able so far to reproduce it myself

[filiptdz]

@RonRadtke My best guess is this isn't a problem caused by this library, but instead any other issue that causes the React Native bundler not to resolve the native modules. A good solution might be to update it not to crash when the native module isn't found, so people aren't drawn to the conclusion that there may be a problem with this library

[rusty120]

@RonRadtke I can confirm the changes above resolve the issue for me. I pulled the repo and tested it locally. I ended up simply going with manual linking however to avoid having to fork the repo in the short term. If you use npx create-react-native-library ... to create a new node modules you'll notice the template includes react and react-native as peer dependencies, so I'm pretty sure they should be there.

I suspect the issue doesn't happen if you have react-native installed globally or use npx react-native bundle to build, which is maybe why not as many people have been tripped up by this?

[AlixH]

I have the same issue with react-native-blob-util 0.13.7 and react native 0.64.3
I don't understand why it occurs without updating anything. It was working before

[ethankong113]

I tried both adding peerDependencies and manually linking.. neither works for me. Maybe it's because I'm using expo

[RonRadtke]

The library doesn't work with expo since it is using native code

[403access]

Hey together,

had some problems with react-native-pdf which is relying on this library as it seems.

Anyhow, whoever uses Expo might be interested in how to run native code - might help resolving your issues:
wonday/react-native-pdf#624 (comment)