Bunches Tool Set

Set of tools for storing similar git-branches in a single branch by moving files that have changes to bunch-files, files with additional special extension.

plugin.xml
plugin.xml.172 <-- Bunch file for Idea 2017.2
SomeAction.java
SomeAction.java.181 <-- Bunch file for Idea 2018.1

Such fake branches have several advantages for plugin development over classic approach when each IDEA version is stored in a separate branch:

• Files for each version are available locally. "Compare Files" action in IDE can be used to see the difference in files.
• Each commit can have own changes for different IDEA-versions.
• Conflicting problems can be spotted and fixed before commit.
• No tedious git branch administration.

The main disadvantages are:

• Bunch files should be removed before building artifacts if build tool tends to pack them into binaries.
• Bunch files should be processed during commit phase even if there are no conflicts from classic git merge perspective (different parts of file are changed).

This approach works well when number of bunch-files is reasonable small or they never change. 
The best practice is to have bunch files only for solving API compatibility issues, and maintain 
same source for all supported IDEA-versions in other files.

This tool set is used in Kotlin project.

Install

The latest release can be obtained from:

https://github.com/JetBrains/bunches/releases

macOS users can install it via brew:

brew tap jetbrains/utils
brew install bunches

Operations

• switch - restores state of files for the particular branch. This command is used during the build, and should be used if development with non-based platform is needed.
• cp - cherry-picks commit to master branch with auto-creating bunch files with given suffix for all affected files.
• cleanup - removes all bunch files from the repository directory. This command is executed on buildserver to avoid appearing bunch files in result binaries. --ext=<suffix> option can be passed to clean bunch files with the specific extension.
• check - checks the range of commits for forgotten bunch files.
• reduce - locates bunch files that are equal to base files (an equality check ignores whitespaces).

.bunch file format

173 // Base branch
// Switch rules
172
as31
as32_181
181
182_181

Each line from switch rules section describes how to switch to the branch mentioned at the beginning of the line. For example for Android Studio 3.2, rule as32_181_173 will be applied (base 173 branch is added implicitly).

Switch tool will do following steps when it gets as32_181_173 as input for each base file in repository:

• If as32 bunch-file is present, replace base file with it and continue to other file;
• If 181 bunch file is present, replace base file with it and continue to other file;
• Leave base version of the file (file from 173 branch) and continue to other file;