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CalculatorTest.java

/*
 * Copyright 2015, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.android.testing.androidjunitrunnersample;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

import android.support.test.filters.SmallTest;
import android.support.test.runner.AndroidJUnit4;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;

/**
 * JUnit4 unit tests for the calculator logic.
 */
@RunWith(AndroidJUnit4.class)
@SmallTest
public class CalculatorTest {

private Calculator mCalculator;

@Before
    public void setUp() {
        mCalculator = new Calculator();
    }

@Test
    public void addTwoNumbers() {
        double resultAdd = mCalculator.add(1d, 1d);
        assertThat(resultAdd, is(equalTo(2d)));
    }

@Test
    public void subTwoNumbers() {
        double resultSub = mCalculator.sub(1d, 1d);
        assertThat(resultSub, is(equalTo(0d)));
    }

@Test
    public void subWorksWithNegativeResult() {
        double resultSub = mCalculator.sub(1d, 17d);
        assertThat(resultSub, is(equalTo(-16d)));
    }

@Test
    public void divTwoNumbers() {
        double resultDiv = mCalculator.div(32d,2d);
        assertThat(resultDiv, is(equalTo(16d)));
    }

@Test(expected = IllegalArgumentException.class)
    public void divDivideByZeroThrows() {
        mCalculator.div(32d,0d);
    }

@Test
    public void mulTwoNumbers() {
        double resultMul = mCalculator.mul(32d, 2d);
        assertThat(resultMul, is(equalTo(64d)));
    }

}