# JS: No Front-End Coverage

### Problem <a href="#problem" id="problem"></a>

I have instrumented my code and used it however I see no coverage reported for my files.

### Solutions <a href="#solutions" id="solutions"></a>

#### Disable caching in your Browser <a href="#disable-caching-in-your-browser" id="disable-caching-in-your-browser"></a>

In Chrome, open the Developer mode (F12), and check the 'Disable cache option under the Network tab.

<figure><img src="https://4057366433-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FAjqTCMRYvHhDgsdPLUnc%2Fuploads%2F1TM34mjYzLwb7VjsYbu7%2Fimage2019-6-20_18-23-27.png?alt=media&#x26;token=3eec21e3-7469-4735-ab97-bc22c1035ccd" alt=""><figcaption></figcaption></figure>

#### Validate the Instrumentation and build number in the JS source from the Browser <a href="#validate-the-instrumentation-and-build-number-in-the-js-source-from-the-browser" id="validate-the-instrumentation-and-build-number-in-the-js-source-from-the-browser"></a>

In your Browser, open the source code of your JS page: is there the Sealights' instrumentation code and the right build number?

<figure><img src="https://4057366433-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FAjqTCMRYvHhDgsdPLUnc%2Fuploads%2FtzZF9S1OtnGgFIrFEw4P%2Fimage2019-6-23_10-45-51.png?alt=media&#x26;token=1b5314a6-b630-4103-a23a-faf52f277392" alt=""><figcaption></figcaption></figure>

#### Validate the application is using instrumented source and not compressed files from the Build stage  <a href="#validate-the-application-is-using-instrumented-source-and-not-compressed-files-from-the-build-stage" id="validate-the-application-is-using-instrumented-source-and-not-compressed-files-from-the-build-stage"></a>

* Check JS is not compressed at the Application Server and therefore confirm the instrumented files are the one used

#### Validate the application is using the static instrumented files and not files in memory <a href="#validate-the-application-is-using-the-static-instrumented-files-and-not-files-in-memory" id="validate-the-application-is-using-the-static-instrumented-files-and-not-files-in-memory"></a>

* Check your configuration is not using a In-Memory server (e.g. Webpack's server) and serves to your browser client the static files instrumented
* You can try a simple http server like [httpster ](https://www.npmjs.com/package/httpster)for a quick validation via a command similar to `httpster -p 8080 -d /home/somedir/public_html`

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