How to manage Runtime permissions android marshmallow espresso tests

You can grant and revoke permissions using:

adb shell pm grant com.package.myapp android.permission.<PERMISSION>
adb shell pm revoke com.package.myapp android.permission.<PERMISSION>

To use from Java instrumentation tests call this method from Google samples: https://github.com/googlesamples/android-testing/blob/ed62c450e43f859333b3113d44dd59f75971b529/ui/espresso/IntentsBasicSample/app/src/androidTest/java/com/example/android/testing/espresso/BasicSample/DialerActivityTest.java#L94

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Outdated answer: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