Note: This project still works perfectly. But since Android Studio 3.0, Google has introduced a new tool - apkanalyzer, which provides a native solution to easily fetch permissions from apk file (apkanalyzer manifest permissions <your_application>.apk). My new project based on apkanalyzer can be found here.

Permission matters! That's what the users care the most. Users are always suspicious of why on earth the app needs any of the permissions, they hate every permission from the bottom of heart. It would be better to check if you have added any new permission to your Android app by any means (e.g. the external library could bring some new permissions). Otherwise, the app new version's adoption rate would be affected.

This script could help warn developers of any permission change by setting up a CI job.

• Ruby
• rake gem (can install by running gem install rake)

$ rake -D

rake examine[android_home,apk_file]
    Examine the apk and the snapshot to compare the permission change

rake take_snapshot[android_home,apk_file]
    Generate the reference snapshot file, before the first run

• Before running the regular CI job, you must generate a snapshot file first:

rake take_snapshot[<ANDROID_SDK_PATH>,<ANDROID_APK_PATH>]

• If you use zsh, you may encounter no matches found, then please try to add \ before bracket, like below:

rake examine\[<ANDROID_SDK_PATH>,<ANDROID_APK_PATH>\]

• Build -> Execute shell -> Command

#!/usr/bin/env bash
cd <DIRECTORY_OF_THIS_SCRIPT>
rake examine[<ANDROID_SDK_PATH>,<ANDROID_APK_PATH>]

There are 4 possible cases (++, --, ++&--, ==), and the results could look like the example output below:

• permission++
• => Failure (exit code 1)

======================================================================
4 new permissions added:
    android.permission.CAMERA
    android.permission.FLASHLIGHT
    android.permission.SEND_SMS
    com.me.app.myapp.permission.DEADLY_ACTIVITY
======================================================================

• permission++ & permission--
• => Failure (exit code 1)

======================================================================
4 new permissions added:
    android.permission.WRITE_EXTERNAL_STORAGE
    com.sonyericsson.home.permission.BROADCAST_BADGE
    com.sec.android.provider.badge.permission.READ
    com.sec.android.provider.badge.permission.WRITE

2 old permissions removed:
    android.permission.CAMERA
    android.permission.FLASHLIGHT
======================================================================

• permission--
• => Success (exit code 0) & update snapshot automatically

======================================================================
Brilliant!  You got 3 permissions removed:
    android.permission.CAMERA
    android.permission.FLASHLIGHT
    com.me.app.myapp.permission.DEADLY_ACTIVITY

Snapshot file has been updated.
======================================================================

• permission==
• => Success (exit code 0)

======================================================================
No permission is changed.
======================================================================

There are different ways of reading permissions from Android, and each one could lead to different results. But reading from APK is the most reliable approach, it shows all permissions.

For example, in my project:

• uses-permission in AndroidManifest.xml (before merging) => 9
• requestedPermissions.length => 19
• permissionGroup.size() => 32

Code snippet

• PackageInfo#requestedPermissions

Context context = this.getApplicationContext();
PackageManager pm = context.getPackageManager();
PackageInfo packageInfo = null;
try {
    packageInfo = pm.getPackageInfo("com.foo.bar", PackageManager.GET_PERMISSIONS);
} catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}
if (packageInfo != null) {
    String[] requestedPermissions = packageInfo.requestedPermissions;
    Log.i("XXX", String.valueOf(requestedPermissions.length));
    for (String permission : requestedPermissions) {
        Log.i("XXX", permission);
    }
}

// => I/XXX﹕ android.permission.CAMERA

• PackageManager#getAllPermissionGroups(x)

Context context = this.getApplicationContext();
PackageManager pm = context.getPackageManager();
List<PermissionGroupInfo> permissionGroup = pm.getAllPermissionGroups(0);
Log.i("XXX", String.valueOf(permissionGroup.size()));
for (PermissionGroupInfo permissionGroupInfo : permissionGroup) {
    Log.i("XXX", permissionGroupInfo.loadLabel(pm).toString());
}

// => I/XXX﹕ Camera

One last thing

I also tried to write unit test with Robolectric to assert new permissions, but I did not use the latest version of Robolectric, thus Robolectric.buildActivity(XxxActivity.class).get() doesn't return the real complete activity. As a result, this way doesn't show all permissions.