Although version 4.2 is considered a minor update, it still packs a host of features focused mainly on productivity, including more advanced support for GitHub pull requests.
In trying to upgrade the experience of its users working with the IDE, it brings improvements to several such components like the Database Inspector, the Layout Inspector, the Systems Trace, the Apply Changes and Gradle.
Starting with the Database Inspector, its surface has now become larger and resizable and also indexes the SQL query history so that you can browse through all past executed queries.
On yet another Inspector component front, the Layout Inspector, a tool which updates the UI as you interact with the app, has now been updated with the added ability of disabling the live updates and instead refreshing manually whenever the user wants to.
Metrics for analyzing performance. Metrics such as the state of image buffers , CPU frequency by core and memory usage are now easier to track through a dedicated tab.
“Apply Changes”, a feature which lets you push code and resource changes without restarting your app, now also supports adding static final primitive fields.
On the Gradle side, Safe Args the Gradle plug-in that generates simple object and builder classes for type safe navigation, has been upgraded with autocompletion and code navigation from source to XML.
Also the Android Gradle plugin 4.2 now supports both APK v3 and APK v4 signing formats, adds a new resource compiler which improves build performance especially on Windows, and gets upgraded to Java programming language version 8.
The most useful update Gradle-wise, however, is the introduction of the Upgrade Assistant, a tool that allows previewing the changes before upgrading your project to the latest Android Gradle plugin :
The assistant allows you to toggle the commands that will be executed on your project to upgrade to a higher version of AGP, preview exactly which files will be affected by the AGP upgrade, and lastly globally update deprecated configurations.
Other enhancements in no particular order are that the multiple device deployment option has been brought back and the new project wizard became more user friendly.
Finally, Studio 4.2 gets all the updates that IntelliJ IDEA Community Edition 2020.2 brings, since Android Studio is based on Intellij. That includes more advanced support for GitHub pull requests and a new Inspections Widget that displays the number of warnings and errors in an opened file thus allowing for quickly navigating between them.