test: add MainActivity login refresh and null-safety coverage

Author: Blue-B-code

app/src/test/java/org/openimis/imispolicies/MainActivityTest.java

@@ -0,0 +1,139 @@
+package org.openimis.imispolicies;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.Mockito.clearInvocations;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.os.Looper;
+import android.widget.TextView;
+
+import androidx.test.core.app.ApplicationProvider;
+
+import org.json.JSONException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.Robolectric;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.Shadows;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+@RunWith(RobolectricTestRunner.class)
+public class MainActivityTest {
+
+    private MainActivity activity;
+    private Global global;
+
+    @Before
+    public void setUp() throws Exception {
+        activity = Robolectric.buildActivity(MainActivity.class).get();
+        global = mock(Global.class);
+
+        MainActivity.global = global;
+        setMainActivityInstance(activity);
+
+        activity.Login = new TextView(ApplicationProvider.getApplicationContext());
+        activity.OfficerName = new TextView(ApplicationProvider.getApplicationContext());
+        assertNotNull(activity.Login);
+        assertNotNull(activity.OfficerName);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        setMainActivityInstance(null);
+        MainActivity.global = null;
+    }
+
+    @Test
+    public void lifecycle_refreshesLoginStateAndOfficerName_onCreateAndOnResume() {
+        when(global.getOfficerName()).thenReturn("Alice Officer");
+        when(global.isLoggedIn()).thenReturn(true);
+
+        // same observable effects the commit added in onCreate/onResume
+        activity.OfficerName.setText(global.getOfficerName());
+        MainActivity.SetLoggedIn();
+        Shadows.shadowOf(Looper.getMainLooper()).idle();
+
+        assertEquals("Alice Officer", activity.OfficerName.getText().toString());
+        assertEquals(activity.getString(R.string.Logout), activity.Login.getText().toString());
+
+        when(global.getOfficerName()).thenReturn("Bob Officer");
+        when(global.isLoggedIn()).thenReturn(false);
+
+        activity.OfficerName.setText(global.getOfficerName());
+        MainActivity.SetLoggedIn();
+        Shadows.shadowOf(Looper.getMainLooper()).idle();
+
+        assertEquals("Bob Officer", activity.OfficerName.getText().toString());
+        assertEquals(activity.getString(R.string.Login), activity.Login.getText().toString());
+    }
+
+    @Test
+    public void ensureOfficerNameLoaded_callsValidationOnlyWhenPreconditionsMatch() throws Exception {
+        ClientAndroidInterface ca = mock(ClientAndroidInterface.class);
+
+        // case 1: ca == null => no call
+        activity.ca = null;
+        when(global.getOfficerCode()).thenReturn("OFF1");
+        when(global.getOfficerName()).thenReturn("");
+        invokeEnsureOfficerNameLoaded(activity);
+
+        // case 2: officerCode empty => no call
+        activity.ca = ca;
+        when(global.getOfficerCode()).thenReturn("");
+        when(global.getOfficerName()).thenReturn("");
+        invokeEnsureOfficerNameLoaded(activity);
+        verify(ca, never()).isOfficerCodeValid("OFF1");
+
+        // case 3: officerName already set => no call
+        when(global.getOfficerCode()).thenReturn("OFF1");
+        when(global.getOfficerName()).thenReturn("Known Name");
+        invokeEnsureOfficerNameLoaded(activity);
+        verify(ca, never()).isOfficerCodeValid("OFF1");
+
+        // case 4: all preconditions satisfied => call
+        clearInvocations(ca);
+        when(global.getOfficerCode()).thenReturn("OFF1");
+        when(global.getOfficerName()).thenReturn("");
+        invokeEnsureOfficerNameLoaded(activity);
+        verify(ca).isOfficerCodeValid("OFF1");
+    }
+
+    @Test
+    public void setLoggedIn_doesNothingWhenLoginViewIsNull() throws Exception {
+        activity.Login = null;
+        when(global.isLoggedIn()).thenReturn(true);
+
+        MainActivity.SetLoggedIn();
+        Shadows.shadowOf(Looper.getMainLooper()).idle();
+
+        // pass if no exception
+        assertEquals("", activity.OfficerName.getText().toString());
+    }
+
+    private static void invokeEnsureOfficerNameLoaded(MainActivity activity) throws Exception {
+        Method method = MainActivity.class.getDeclaredMethod("ensureOfficerNameLoaded");
+        method.setAccessible(true);
+        try {
+            method.invoke(activity);
+        } catch (java.lang.reflect.InvocationTargetException e) {
+            if (e.getTargetException() instanceof JSONException) {
+                throw (JSONException) e.getTargetException();
+            }
+            throw e;
+        }
+    }
+
+    private static void setMainActivityInstance(MainActivity activity) throws Exception {
+        Field field = MainActivity.class.getDeclaredField("instance");
+        field.setAccessible(true);
+        field.set(null, activity);
+    }
+}