How to get context in Robolectric Unit test with SQLite in Android

Question

I would like to do some Unit test in Android for SQLiteOpenHelper using Robolelectric. However, I can't create the database as I can't get the context. I tried out 4 options that are mentioned here How can we access context of an application in Robolectric? but none of them worked. Here you see the code of the testclass and in the "setUp" method you see the different options that I tried with the corresponding error message after //

package com.example.td.barapp;

import android.content.Context;
import android.database.Cursor;

import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.robolectric.RobolectricTestRunner;
import org.robolectric.RuntimeEnvironment;


@RunWith(RobolectricTestRunner.class)


public class DataBaseHelperTest {

    private DataBaseHelper helperDB;


    @Before
    public void setUp() throws Exception {
        // Context context = ShadowApplication.getInstance().applicationContext; //Error: Cannot resolve symbol 'applicationContext'
        //Context context = Robolectric.application; // Error: Cannot resolve symbol application
        //Context context = ApplicationProvider.getApplicationContext(); // Error: Cannot resolve symbol 'ApplicationProvider'
        //Context context = RuntimeEnvironment.systemContext; // Error: Cannot resolve symbol 'systemContext'
//Context context = getClass().getClassLoader(); // Error: Required type: Context Provided: ClassLoader
        Context context = InstrumentationRegistry.getInstrumentation().getContext(); // Error: Cannot resolve symbol 'InstrumentationRegistry'
        helperDB = new DataBaseHelper(context);
    }

    @After
    public void tearDown() {
        helperDB.close();
    }

    @Test
    public void insertDataDB_TableRatings() {
        boolean insertRating = helperDB.insertDataDB_TableRatings("Orange Juice", "Any", "Any", 1,
                0,0,1,0,0 );

        Assert.assertTrue(insertRating);
    }

    @Test
    public void getDataDB_TableRating() {
        String drinkName = "Orange Juice";
        String drinkStrength = "Any";
        String drinkSize = "Any";

        boolean insertRating = helperDB.insertDataDB_TableRatings(drinkName, drinkStrength, drinkSize, 1,
                0,0,1,0,0 );


        Cursor res = helperDB.getDataDB_TableRating(drinkName, drinkStrength, drinkSize);
        Assert.assertFalse(res.getCount()==0);

        res.moveToFirst();
        Assert.assertEquals (res.getString(0), drinkName);
        Assert.assertEquals (res.getString(6), "1");

        drinkSize = "Large";

        boolean insertRating2 = helperDB.insertDataDB_TableRatings(drinkName, drinkStrength, drinkSize, 1,
                0,0,0,1,0 );

        res = helperDB.getDataDB_TableRating(drinkName, drinkStrength, drinkSize);
        Assert.assertFalse(res.getCount()==0);

        res.moveToFirst();
        Assert.assertEquals (res.getString(2), drinkName);
        Assert.assertEquals (res.getString(7), "1");


    }

    @Test
    public void updateDataDB_TableRatings() {
        String drinkName = "Orange Juice";
        String drinkStrength = "Any";
        String drinkSize = "Any";

        boolean insertRating = helperDB.insertDataDB_TableRatings(drinkName, drinkStrength, drinkSize, 1, 0,0,1,0,0 );
        boolean valueUpdated = helperDB.updateDataDB_TableRatings(drinkName, drinkStrength , drinkSize, 2, 0, 0, 0, 1, 0);

        Cursor res = helperDB.getDataDB_TableRating(drinkName, drinkStrength, drinkSize);
        Assert.assertFalse(res.getCount()==0);
        res.moveToFirst();
        Assert.assertEquals (res.getString(8), "1");
    }

    @Test
    public void deleteDataDB_TableRatings() {
        String drinkName = "Orange Juice";
        String drinkStrength = "Any";
        String drinkSize = "Large";

        boolean insertRating = helperDB.insertDataDB_TableRatings(drinkName, drinkStrength, drinkSize, 1, 0,0,1,0,0 );
        helperDB.deleteDataDB_TableRatings (drinkName, drinkStrength, drinkSize);
    }
}

I also added the following lines in my build.gradle file:

testImplementation 'junit:junit:4.13'
testImplementation 'org.robolectric:robolectric:3.0'
androidTestImplementation 'androidx.test:runner:1.2.0'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'

Would you mind telling me what mistake I am making? I'd appreciate every comment.

Update: As it seems that I might be missing some dependencies I uploaded the build.gradle file with the dependencies. Would you mind telling me what the mistake is and why I can't get any context with Roblectric?

apply plugin: 'com.android.application'
apply plugin: "androidx.navigation.safeargs"


android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.td.barapp"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        viewBinding {
            enabled = true
        }
        dataBinding {
            enabled=true
        }

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    def nav_version = "2.3.0"
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.android.material:material:1.2.0-alpha06'
    testImplementation 'junit:junit:4.13'
    testImplementation 'org.robolectric:robolectric:3.0'
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    androidTestImplementation 'android.arch.core:core-testing:1.2.1'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation "androidx.recyclerview:recyclerview:1.1.0"
    implementation 'androidx.cardview:cardview:1.0.0'
    implementation "androidx.navigation:navigation-fragment:$nav_version"
    implementation "androidx.navigation:navigation-ui:$nav_version"


}

Answer 1

I am pretty sure that you cannot test SQLite with robolectric. My room tests, for instance, only run in AndroidTest/Instrumented. If you are willing to change to Room instead of using SQLite directly, its testing is well documented.

If you want to learn more about room there is this code lab.

And if you wanna learn more about its testing you can check it here.