EmptyRecyclerViewTest.java

package com.nilhcem.bblfr.core.ui.recyclerview;

import android.os.Build;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

import com.nilhcem.bblfr.BuildConfig;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.RobolectricTestRunner;
import org.robolectric.RuntimeEnvironment;
import org.robolectric.annotation.Config;

import static com.google.common.truth.Truth.assertThat;

@RunWith(RobolectricTestRunner.class)
@Config(constants = BuildConfig.class, sdk = Build.VERSION_CODES.M)
public class EmptyRecyclerViewTest {

    private EmptyRecyclerView recyclerView;
    private View emptyView;

    @Before
    public void setup() {
        emptyView = new View(RuntimeEnvironment.application);
        recyclerView = new EmptyRecyclerView(RuntimeEnvironment.application);
        recyclerView.setEmptyView(emptyView);
    }

    @Test
    public void should_show_empty_view_if_adapter_is_empty() {
        // Given
        RecyclerView.Adapter adapter = new RecyclerView.Adapter() {
            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return null;
            }

            @Override
            public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            }

            @Override
            public int getItemCount() {
                return 0;
            }
        };

        // When
        recyclerView.setAdapter(adapter);

        // Then
        assertThat(emptyView.getVisibility()).isEqualTo(View.VISIBLE);
    }

    @Test
    public void should_hide_empty_view_if_adapter_has_data() {
        // Given
        RecyclerView.Adapter adapter = new RecyclerView.Adapter() {
            @Override
            public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return null;
            }

            @Override
            public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            }

            @Override
            public int getItemCount() {
                return 2;
            }
        };

        // When
        recyclerView.setAdapter(adapter);

        // Then
        assertThat(emptyView.getVisibility()).isEqualTo(View.GONE);
    }
}