Add test readme.

tests/unit/linux/wpa-controller/README.md

@@ -0,0 +1,25 @@
+
+# WPA Controller Tests
+
+## Wi-Fi Drivers and WPA Daemons
+
+Some of the tests that exercise wpa daemon (hostapd, wpa_supplicant) functionality require a wlan device driver and a running instance of the daemon. To satisfy these requirements, the mac80211_hwsim driver is used to create a virtualized wlan device that the wpa daemon can then control. Helpers are provided for managing the virtualized wlan device(s) with [WifiVirtualDeviceManager](./detail/WifiVirtualDeviceManager.hxx) and for managing the wpa daemons with [WpaDaemonManager](./detail/WpaDaemonManager.hxx) and [WpaDaemonInstance](./detail/WpaDaemonInstance.hxx).
+
+Presently, the tests use [event listeners](https://github.com/catchorg/Catch2/blob/devel/docs/event-listeners.md) from the [Catch2](https://github.com/catchorg/Catch2) unit test framework instead of traditional, class-based setup/teardown fixtures. The event listeners have access to test case information such as the test case name and their tags. The [WpaDaemonCatch2EventListener](./detail/WpaDaemonCatch2EventListener.hxx) was developed to detect when a test case requires either of the daemons, and automatically creates a wlan driver and starts the required daemon . Similarly, it handles removing the driver instances and stopping the daemons on test case completion.
+
+To trigger this behavior, the test case must include a tag that corresponds to the name of a [WpaType](../../../../linux/wpa-controller/include/Wpa/WpaCore.hxx) enumeration value (a case insensitive comparison is done). For example, if the hostapd daemon is needed for the test, then a tag corresponding to WpaType::Hosapd is needed in the test case definition, for example '**hostapd**' as shown below:
+
+```C++
+TEST_CASE("Send command: GetStatus()", "[wpa][hostapd][client][remote]")
+```
+
+Only the first `WpaType` will be used. Failure to add the appropriate tag will cause the test to fail since no daemon will be running and thus, no connection to it will be possible.
+
+### Future Work
+
+This method will be improved in the future, with some possible improvements including:
+
+1. Allow multiple wpa daemon types.
+2. Allow a more generic daemon specification (eg. `[wpaDaemon=hostapd]`)
+3. Replacement of event-based fixtures to class-based fixtures.
+