---
title: upstream
framework: combine
role: symbol
role_heading: Instance Property
path: combine/publishers/assertnofailure/upstream
---

# upstream

The publisher from which this publisher receives elements.

## Declaration

```swift
let upstream: Upstream
```

## See Also

### Inspecting publisher properties

- [file](combine/publishers/assertnofailure/file.md)
- [line](combine/publishers/assertnofailure/line.md)
- [prefix](combine/publishers/assertnofailure/prefix.md)