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# XCTestObserver

An object that observes test activity and events.

```
class XCTestObserver
```

## Topics

### Starting and Stopping Test Observation

[`startObserving()`](/documentation/XCTest/XCTestObserver/startObserving())

Starts observing a test.

[`stopObserving()`](/documentation/XCTest/XCTestObserver/stopObserving())

Stops observing a test.

### Monitoring Test Activity

[`testCaseDidFail(_:withDescription:inFile:atLine:)`](/documentation/XCTest/XCTestObserver/testCaseDidFail(_:withDescription:inFile:atLine:))

Notifies the observer when a test case fails.

[`testCaseDidStart(_:)`](/documentation/XCTest/XCTestObserver/testCaseDidStart(_:))

Notifies the observer when a test case starts.

[`testCaseDidStop(_:)`](/documentation/XCTest/XCTestObserver/testCaseDidStop(_:))

Notifies the observer when a test case stops.

[`testSuiteDidStart(_:)`](/documentation/XCTest/XCTestObserver/testSuiteDidStart(_:))

Notifies the observer when a test suite starts.

[`testSuiteDidStop(_:)`](/documentation/XCTest/XCTestObserver/testSuiteDidStop(_:))

Notifies the observer when a test suite stops.


---

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