Telemetry entry reporting Java NullPointerException error in `deviceInfo` section

[dianabarsan]

Describe the bug
I came across a telemetry entry that had this message in the device section:

"userAgent": "Mozilla/5.0 (Linux; Android 7.0; TECNO WX3P Build/NRD90M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Crosswalk/23.53.589.4 Mobile Safari/537.36 org.livinggoods.smarthealth.region1.ug/v0.4.33",
    "deviceInfo": {
      "error": true,
      "message": "Problem fetching device info: class java.lang.NullPointerException: Attempt to invoke virtual method 'int android.net.NetworkCapabilities.getLinkDownstreamBandwidthKbps()' on a null object reference"
    },

Link to forum post sharing the full telemetry entry: https://forum.communityhealthtoolkit.org/t/error-loading-tasks/2471/9

To Reproduce
Unclear on the reproduction steps. I have tried removing sims, enabling airplane mode, enabling extreme battery saver and my test device still returned network capabilities.

Loading the CHT About page should query the cht-android getDeviceInfo.

Expected behavior
Even if the device has no network capabilities, the app should not throw an error.

Development steps

• Update the getDeviceInfo function to correctly treat null values from getNetworkCapabilities
• Add Unit test to validate the behavior. There are no unit tests yet for this class. The new unit test file should be added in this folder: https://github.com/medic/cht-android/tree/1813da726a4ba3b1cb83221a216b42df45145675/src/main/java/org/medicmobile/webapp/mobile

[garethbowen]

Looks like null is a valid return value: https://developer.android.com/reference/android/net/ConnectivityManager#getNetworkCapabilities(android.net.Network)

Need to add null check here:

cht-android/src/main/java/org/medicmobile/webapp/mobile/MedicAndroidJavascript.java

Line 284 in 8ab2db6

NetworkCapabilities networkCapabilities = connectivityManager.getNetworkCapabilities(connectivityManager.getActiveNetwork());

[JallaSravani1]

Hi! i want to work on this issue

May be

The crash happens because the app expects a network capability that is sometimes not there.

To rectify, update the code to check for null before calling methods on NetworkCapabilities.