How to manage Runtime permissions android marshmallow espresso tests

Question

I'm using espresso for testing but sometimes I try to get an image form external storage and with marshmallow I need a Runtime permission otherwise there will be an Exception crash and the test will fail.

androidTestCompile 'com.android.support.test:runner:0.4'
androidTestCompile 'com.android.support.test:rules:0.4'
androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.1'
androidTestCompile 'com.android.support.test.espresso:espresso-intents:2.2.1'
androidTestCompile('com.android.support.test.espresso:espresso-contrib:2.2.1') {
    // this library uses the newest app compat v22 but the espresso contrib still v21.
    // you have to specifically exclude the older versions of the contrib library or
    // there will be some conflicts
    exclude group: 'com.android.support', module: 'appcompat'
    exclude group: 'com.android.support', module: 'support-v4'
    exclude module: 'recyclerview-v7'
}
androidTestCompile 'junit:junit:4.12'
androidTestCompile 'com.squareup.retrofit:retrofit-mock:1.9.0'
androidTestCompile 'com.squareup.assertj:assertj-android:1.1.0'
androidTestCompile 'com.squareup.spoon:spoon-client:1.2.0'

how can I manage that right?

should I write test for Runtime permissions or there's a way to disable it for testing?

should I give permissions before the tests run like she says here? https://www.youtube.com/watch?list=PLWz5rJ2EKKc-lJo_RGGXL2Psr8vVCTWjM&v=C8lUdPVSzDk

Answer 1

UPDATE! Now you can use Rule from Android Testing Support Library

It is more proper to use than custom rules.

Outdated answer:

You can add test rule to reuse code and add more flexibility:

/**
 * This rule adds selected permissions to test app
 */

public class PermissionsRule implements TestRule {

    private final String[] permissions;

    public PermissionsRule(String[] permissions) {
        this.permissions = permissions;
    }

    @Override
    public Statement apply(final Statement base, Description description) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {

                allowPermissions();

                base.evaluate();

                revokePermissions();
            }
        };
    }

    private void allowPermissions() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            for (String permission : permissions) {
                InstrumentationRegistry.getInstrumentation().getUiAutomation().executeShellCommand(
                        "pm grant " + InstrumentationRegistry.getTargetContext().getPackageName()
                                + " " + permission);
            }
        }
    }

    private void revokePermissions() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            for (String permission : permissions) {
                InstrumentationRegistry.getInstrumentation().getUiAutomation().executeShellCommand(
                        "pm revoke " + InstrumentationRegistry.getTargetContext().getPackageName()
                                + " " + permission);
            }
        }
    }
}

After that you can use this rule in your test classes:

@Rule
public final PermissionsRule permissionsRule = new PermissionsRule(
new String[]{Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS});

Keep in mind:

1. Rule does not affect on @Before methods because all rules are executed after that
2. executeShellCommand is asynchronous and if you need accepted permissions right after test started consider adding some delay