TypeError: Cannot read property 'BEFORE' of undefined

[ftr9]

I followed the official installation instructions for the Amplitude React Native SDK in my Expo app

📄 Docs: Amplitude React Native SDK

Expected Behavior

The SDK should initialize correctly and allow event tracking.

ℹ️ Note: I’m not using Expo Go. The app runs in a development build.

What I implemented:

1. Initialization

2. Event Tracking

Current Behavior

The SDK throws an error trying to access a property on undefined.

Error Screenshot

Possible Solution

I investigated the SDK source and found that PluginType was undefined where PluginType.BEFORE was being accessed.

🔧 Fix (Temporary Workaround)

• I commented out the existing PluginType reference.
• Then I manually defined PluginType right where the crash occurred.
• After this, the SDK started working, and events appeared on the Amplitude dashboard.

Before Modification

After Modification

Terminal Output

Event Received in Dashboard

Steps to Reproduce

1. Follow the official Amplitude SDK installation guide.
2. Set up the SDK in an Expo development build (not Expo Go).
3. Run the app with the following environment:

• React Native: 0.79.3
• Expo SDK: 53.0.10
• Node.js: 20.16.0
• Eas-cli: 15.0.12

Environment

• JS SDK Version: @amplitude/analytics-react-native:^1.4.13
• Installation Method: npm
• React Native: 0.79.3
• Expo SDK: 53.0.10
• Eas-cli: 15.0.12

[stackchain]

getting a similar issue with same version + ampli cli, but getting DESTINATION instead of BEFORE.

[Cussone]

Getting the same issue.

Although I started from 1.4.13 and downgraded to 1.3.6. Each version had the same problem.

[aliaksandr-kazarez]

@ftr9 thank you for detailed bug report. Would you be able to confirm version of @amplitude/analytics-types package installed?

by either doing yarn list --pattern @amplitude for yarn or npm list --all | grep "amplitude" if you're using NPM, and share the output.

[ftr9]

@aliaksandr-kazarez

Sorry for the late reply!

Previously, when it failed to run, I uninstalled everything and left it for about a week. Today, I tried reinstalling, and this time it worked—I can see events being tracked without any errors ✅✅.

Regarding @amplitude/analytics-types, these are the currently available types and the dependencies:

@amplitude/analytics-react-native: "^1.4.13"
@react-native-async-storage/async-storage: "^2.2.0"

[jorbuedo]

Still not working, these are the versions:

npm list --all | grep "amplitude"
├─┬ @amplitude/ampli@1.36.2
│ ├─┬ @amplitude/identify@1.10.2
│ │ ├── @amplitude/types@1.10.2 deduped
│ │ ├─┬ @amplitude/utils@1.10.2
│ │ │ ├── @amplitude/types@1.10.2 deduped
│ ├─┬ @amplitude/node@1.10.2
│ │ ├── @amplitude/identify@1.10.2 deduped
│ │ ├── @amplitude/types@1.10.2 deduped
│ │ ├── @amplitude/utils@1.10.2 deduped
│ ├── @amplitude/types@1.10.2
├─┬ @amplitude/analytics-react-native@1.4.13
│ ├─┬ @amplitude/analytics-client-common@1.2.5
│ │ ├── @amplitude/analytics-connector@1.6.4
│ │ ├── @amplitude/analytics-core@1.2.7 deduped
│ │ ├── @amplitude/analytics-types@1.3.5
│ ├─┬ @amplitude/analytics-core@1.2.7
│ │ ├── @amplitude/analytics-types@1.3.5
│ ├── @amplitude/analytics-types@1.3.5
│ ├── @amplitude/ua-parser-js@0.7.33
├── @amplitude/analytics-types@2.9.2

I'm seeing in 2.9.2 the enum is gone and is substituted by a union type, which would explain how PluginType.BEFORE would fail since PluginType doesn't exist as en enum anymore.
I think you should add an object PluginType to make up for it here:

Amplitude-TypeScript/packages/analytics-types/src/plugin.ts

Line 9 in d54bd9c

export type PluginType = PluginTypeBefore | PluginTypeEnrichment | PluginTypeDestination;

So that you have:

export const PluginType = {
  BEFORE: 'before',
  ENRICHMENT: 'enrichment',
  DESTINATION: 'destination',
} as const
export type PluginType = (typeof PluginType)[keyof typeof PluginType]

That way PluginType will be exported as both a union type and an object containing the literals, which will make it compatible with current code expecting an enum.