Test Connection.login, invalid login only right now

This starts the process of exercising HTTP features
prior to any contemplated move to OkHttp. More
importantly it makes sure basic HTTP works to guard against
things like issue #5000

AnkiDroid/src/androidTest/java/com.ichi2.anki.tests/libanki/HttpTest.java

@@ -0,0 +1,115 @@
+package com.ichi2.anki.tests.libanki;
+
+import android.Manifest;
+import android.os.Build;
+
+import com.ichi2.async.Connection;
+import com.ichi2.compat.CompatHelper;
+
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.rule.GrantPermissionRule;
+import androidx.test.runner.AndroidJUnit4;
+
+@RunWith(AndroidJUnit4.class)
+public class HttpTest {
+
+    @Rule
+    public GrantPermissionRule mRuntimeStoragePermissionRule = GrantPermissionRule.grant(
+            Manifest.permission.WRITE_EXTERNAL_STORAGE,
+            Manifest.permission.INTERNET,
+            Manifest.permission.ACCESS_NETWORK_STATE);
+
+
+    @Test
+    public void testLogin() {
+
+        // The component under test is a BaseAsyncTask, which has problematic threading below targetSdkVersion API16
+        if (CompatHelper.getSdkVersion() < Build.VERSION_CODES.JELLY_BEAN) {
+            return;
+        }
+
+        String username = "AnkiDroidInstrumentedTestUser";
+        String password = "AnkiDroidInstrumentedTestInvalidPass";
+        Connection.Payload invalidPayload = new Connection.Payload(new Object[]{username, password});
+        TestTaskListener testListener = new TestTaskListener(invalidPayload);
+
+        // We have to carefully run things on the main thread here or the threading protections in BaseAsyncTask throw
+        // The first one is just to run the static initializer, really
+        Runnable onlineRunnable = () -> {
+            try {
+                Class.forName("com.ichi2.async.Connection");
+            } catch (Exception e) {
+                Assert.fail("Unable to load Connection class: " + e.getMessage());
+            }
+        };
+        InstrumentationRegistry.getInstrumentation().runOnMainSync(onlineRunnable);
+
+        // If we are not online this test is not nearly as interesting
+        // TODO simulate offline programmatically - currently exercised by manually toggling an emulator offline pre-test
+        if (!Connection.isOnline()) {
+            Connection.login(testListener, invalidPayload);
+            Assert.assertFalse("Successful login despite being offline", testListener.getPayload().success);
+            Assert.assertTrue("onDisconnected not called despite being offline", testListener.mDisconnectedCalled);
+            return;
+        }
+
+        Runnable r = () -> {
+            Connection conn = Connection.login(testListener, invalidPayload);
+            try {
+                // This forces us to synchronously wait for the AsyncTask to do it's work
+                conn.get();
+            } catch (Exception e) {
+                Assert.fail("Caught exception while trying to login: " + e.getMessage());
+            }
+        };
+        InstrumentationRegistry.getInstrumentation().runOnMainSync(r);
+        Assert.assertFalse("Successful login despite invalid credentials", testListener.getPayload().success);
+    }
+
+
+    public class TestTaskListener implements Connection.TaskListener {
+
+        private Connection.Payload mPayload;
+        private boolean mDisconnectedCalled = false;
+
+        private Connection.Payload getPayload() {
+            return mPayload;
+        }
+
+        private void setPayload(Connection.Payload payload) {
+            mPayload = payload;
+        }
+
+        private TestTaskListener(Connection.Payload payload) {
+            setPayload(payload);
+        }
+
+        @Override
+        public void onPreExecute() {
+            // do nothing
+        }
+
+
+        @Override
+        public void onProgressUpdate(Object... values) {
+            // do nothing
+        }
+
+
+        @Override
+        public void onPostExecute(Connection.Payload data) {
+            // do nothing
+        }
+
+
+        @Override
+        public void onDisconnected() {
+            mDisconnectedCalled = true;
+        }
+    }
+}