Truth Android

A set of Truth assertions geared toward testing Android.

Writing tests is not the most glamorous part of developing an Android application but it is an invaluable one. Using libraries like JUnit and Truth provide a great starting point for writing tests.

This library is an extension of Truth which aims to make it even easier to test Android.

Truth Android
assertThat(view).isGone();
Regular JUnit
assertEquals(View.GONE, view.getVisibility());
Regular Truth
assertThat(view.getVisibility()).isEqualTo(View.GONE);

When failing, the Truth Android assertion produces an output which allows you to immediately recognize the problem: Expected visibility <gone> but was <invisible>.

Compare that to the output of regular Truth expected:<[8]> but was:<[4]> and regular JUnit expected: <8> but was: <4> and you should immediately see the advantage.

Because Truth Android offers assertions directly on objects rather than properties, tests are much more readable.

Truth Android
assertThat(layout).isVisible();
assertThat(layout).isVertical();
assertThat(layout).hasChildCount(4);
assertThat(layout).hasShowDividers(SHOW_DIVIDERS_MIDDLE);
Regular JUnit
assertEquals(View.VISIBLE, layout.getVisibility());
assertEquals(VERTICAL, layout.getOrientation());
assertEquals(4, layout.getChildCount());
assertEquals(SHOW_DIVIDERS_MIDDLE, layout.getShowDividers());
Regular Truth
assertThat(layout.getVisibility()).isEqualTo(View.VISIBLE);
assertThat(layout.getOrientation()).isEqualTo(VERTICAL);
assertThat(layout.getChildCount()).isEqualTo(4);
assertThat(layout.getShowDividers()).isEqualTo(SHOW_DIVIDERS_MIDDLE);

Assertions exist for nearly every object that you would ever want to test, from LinearLayout to ActionBar to Fragment to MenuItem. AndroidX is mostly included too.

To get started writing tests add the following import:

import static com.pkware.truth.android.Assertions.assertThat;
Add-On Modules

Modules are also provided for the add-on AndroidX libraries. Add the dependency (listed below) and use the following imports:

  • legacy-support-core-ui

    import static com.pkware.truth.androidx.legacy.Assertions.assertThat;

  • collection

    import static com.pkware.truth.androidx.collection.Assertions.assertThat;

  • core

    import static com.pkware.truth.androidx.core.Assertions.assertThat;

  • cursoradapter

    import static com.pkware.truth.androidx.cursoradapter.Assertions.assertThat;

  • fragment

    import static com.pkware.truth.androidx.fragment.Assertions.assertThat;

  • Google Play Services

    import static com.pkware.truth.android.playservices.Assertions.assertThat;

  • appcompat

    import static com.pkware.truth.androidx.appcompat.Assertions.assertThat;

  • Material Components

    import static com.pkware.truth.android.material.Assertions.assertThat;

  • loader

    import static com.pkware.truth.androidx.loader.Assertions.assertThat;

  • mediarouter

    import static com.pkware.truth.androidx.mediarouter.Assertions.assertThat;

  • gridlayout

    import static com.pkware.truth.androidx.gridlayout.Assertions.assertThat;

  • cardview

    import static com.pkware.truth.androidx.cardview.Assertions.assertThat;

  • recyclerview

    import static com.pkware.truth.androidx.recyclerview.Assertions.assertThat;

  • pallete

    import static com.pkware.truth.androidx.palette.Assertions.assertThat;

  • print

    import static com.pkware.truth.androidx.print.Assertions.assertThat;

  • slidingpanelayout

    import static com.pkware.truth.androidx.slidingpanelayout.Assertions.assertThat;

  • swiperefreshlayout

    import static com.pkware.truth.androidx.swiperefreshlayout.Assertions.assertThat;

  • viewpager

    import static com.pkware.truth.androidx.viewpager.Assertions.assertThat;
Extending

The provided assertions have also been designed to be extended for any custom controls you have developed.

public class CustomLayout extends LinearLayout {
  public int getBehavior() {
    /* ... */
  }
}

Use the following pattern to set up your assertions.

public final class CustomLayoutSubject extends AbstractLinearLayoutSubject<CustomLayout> {

  @Nullable
  private final CustomLayout actual;

  public static CustomLayoutSubject assertThat(@Nullable CustomLayout actual) {
    return assertAbout(CustomLayoutSubject::new).that(actual);
  }

  private CustomLayoutSubject(FailureStrategy failureStrategy, @Nullable CustomLayout actual) {
    super(failureStrategy, actual);
    this.actual = actual;
  }

  public void hasSomeBehavior() {
    check("getBehavior()")
        .withMessage("Expected some behavior but was doing other behavior.")
        .that(actual.getBehavior())
        .isEqualTo(42);
  }
}

Now static import CustomLayoutSubject.assertThat in your test classes.

For more information about writing custom assertions see the official documentation.

Download

  • Android module:

    androidTestCompile 'com.pkware.truth-android:truth-android:2.0.0'

  • legacy-support-core-ui module:

    androidTestCompile 'com.pkware.truth-android:truth-android-legacy-support-core-ui:2.0.0'

  • collection module:

    androidTestCompile 'com.pkware.truth-android:truth-android-collection:2.0.0'

  • core module:

    androidTestCompile 'com.pkware.truth-android:truth-android-core:2.0.0'

  • cursoradapter module:

    androidTestCompile 'com.pkware.truth-android:truth-android-cursoradapter:2.0.0'

  • fragment module:

    androidTestCompile 'com.pkware.truth-android:truth-android-fragment:2.0.0'

  • Google Play Services module:

    androidTestCompile 'com.pkware.truth-android:truth-android-play-services:2.0.0'

  • Material Components library module:

    androidTestCompile 'com.pkware.truth-android:truth-android-material:2.0.0'

  • appcompat module:

    androidTestCompile 'com.pkware.truth-android:truth-android-appcompat:2.0.0'

  • loader module:

    androidTestCompile 'com.pkware.truth-android:truth-android-loader:2.0.0'

  • mediarouter module:

    androidTestCompile 'com.pkware.truth-android:truth-android-mediarouter:2.0.0'

  • gridlayout module:

    androidTestCompile 'com.pkware.truth-android:truth-android-gridlayout:2.0.0'

  • cardview module:

    androidTestCompile 'com.pkware.truth-android:truth-android-cardview:2.0.0'

  • recyclerview module:

    androidTestCompile 'com.pkware.truth-android:truth-android-recyclerview:2.0.0'

  • pallete module:

    androidTestCompile 'com.pkware.truth-android:truth-android-pallete:2.0.0'

  • print module:

    androidTestCompile 'com.pkware.truth-android:truth-android-print:2.0.0'

  • slidingpanelayout module:

    androidTestCompile 'com.pkware.truth-android:truth-android-slidingpanelayout:2.0.0'

  • swiperefreshlayout module:

    androidTestCompile 'com.pkware.truth-android:truth-android-swiperefreshlayout:2.0.0'

  • viewpager module:

    androidTestCompile 'com.pkware.truth-android:truth-android-viewpager:2.0.0'
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