# Improve Test Optimization With Context Propagation

SeaLights is using [Open Telemetry](https://opentelemetry.io/) to propagate the context of your tests, this allow to enrich the test optimization statistical model to an almost 1:1 relationship between a test and the code of the application it is testing.

There are 2 main ways to propagate the context of a test:

1. The utilization of a baggage
2. The utilization of a cookie

In order to set this up, these are the necessary steps you need to take:

1. Set up the testing framework to set either the baggage or the cookie with the test information, including:
   1. Test name
   2. Test session ID
2. Set up the front-end agent with the flag to enable Open Telemetry usage
3. Set up the backend agent with the flags to enable Open Telemetry usage

### Set Context Propagation on the Node Agent <a href="#heading-title-text" id="heading-title-text"></a>

In order to enable context propagation on the Node Agent, you will need to set the `--enableOpenTelemetry` flag when applying the `scan` command, for example:

{% code overflow="wrap" lineNumbers="true" %}

```
npx slnodejs scan --workspacepath ./MyApp --tokenfile sltoken.txt --buildsessionidfile buildSessionId --scm none --instrumentForBrowsers --enableOpenTelemetry --outputpath "sl_dist"
```

{% endcode %}

### Set Context Propagation on the Java Agent <a href="#heading-title-text" id="heading-title-text"></a>

In order to enable context propagation on the Java Agent, you will need to set the following flags when starting the test listener:

* sl.otelEnabled=true
* sl.otelConfiguration.enabled=true
* sl.otelConfiguration.loadEmbeddedAgent=true
* sl.featuresData.codeCoverageManagerVersion=v3

For example:

{% code overflow="wrap" lineNumbers="true" %}

```
-javaagent:/path/to/sl-test-listener.jar -Dsl.tags=backend -Dsl.labId=<lab ID> -Dsl.otelEnabled=true -Dsl.otelConfiguration.enabled=true -Dsl.otelConfiguration.loadEmbeddedAgent=true -Dsl.featuresData.codeCoverageManagerVersion=v3
```

{% endcode %}

## Testing Frameworks <a href="#heading-title-text" id="heading-title-text"></a>

### Setting Context Propagation with PlayWright <a href="#heading-title-text" id="heading-title-text"></a>

In order to set the context with the baggage, please follow [this guide](https://github.com/Sealights/sealights-integration-examples/tree/main/playwright-browser-agent-otel#2-setting-the-testsessionid-and-testname).

### Setting Context Propagation With Cypress <a href="#heading-title-text" id="heading-title-text"></a>

In order to set the context with the baggage, please follow [this guide](https://github.com/Sealights/sealights-integration-examples/blob/main/cypress-browser-agent-otel/README.md).

### Setting Context Propagation With Gauge <a href="#heading-title-text" id="heading-title-text"></a>

In order to set the context with the baggage, please follow [this guide](https://github.com/Sealights/sealights-integration-examples/blob/main/gauge-browser-agent-otel/README.md).