# Durable Streaming
Demonstrates durable streaming with multiple stream manager backends —
in-memory, Firestore, and Realtime Database. This allows clients to
reconnect and resume consuming stream chunks even after disconnection.
## Features Demonstrated
| Feature | Flow | Description |
|---------|------|-------------|
| Basic Streaming | `streamy` | Counts to N, streaming each step |
| Error Handling | `streamyThrowy` | Throws an error after 3 chunks |
| In-Memory Backend | `/streamy` | Stream manager using in-memory storage |
| Firestore Backend | `/streamyFirestore` | Stream manager backed by Cloud Firestore |
| RTDB Backend | `/streamyRtdb` | Stream manager backed by Realtime Database |
## Setup
### Prerequisites
- **Node.js** (v18 or higher)
- **pnpm** package manager
- **Firebase project** with Firestore and/or Realtime Database enabled
### Build and Install
From the repo root:
```bash
pnpm install
pnpm run setup
```
### Firebase Configuration
Set up Application Default Credentials for Firebase:
```bash
export GOOGLE_APPLICATION_CREDENTIALS='/path/to/service-account-key.json'
```
Or use `gcloud`:
```bash
gcloud auth application-default login
```
## Run the Sample
```bash
pnpm build && pnpm start
```
The Express server starts on port `3500`.
## Testing This Demo
1. **Test in-memory streaming**:
```bash
curl -X POST http://localhost:3500/streamy \
-H "Content-Type: application/json" \
-d '{"data": 5}'
```
2. **Test Firestore-backed streaming**:
```bash
curl -X POST http://localhost:3500/streamyFirestore \
-H "Content-Type: application/json" \
-d '{"data": 5}'
```
3. **Test RTDB-backed streaming**:
```bash
curl -X POST http://localhost:3500/streamyRtdb \
-H "Content-Type: application/json" \
-d '{"data": 5}'
```
4. **Test error handling**:
```bash
curl -X POST http://localhost:3500/streamyThrowy \
-H "Content-Type: application/json" \
-d '{"data": 5}'
```
5. **Expected behavior**:
- `streamy` streams count objects `{count: 0}` through `{count: N-1}`
- `streamyThrowy` streams 3 chunks then throws an error
- All three backends (in-memory, Firestore, RTDB) behave identically
