Rails Gem开发中VERSION文件与Git Tag工作流困惑求助

Great question—this is a common point of confusion when getting into Ruby gem development, since it feels like we're duplicating version info between the VERSION file and Git tags. Let's break this down step by step:

First, these two tools serve entirely different systems, and neither can replace the other:

• The VERSION file is the single source of truth for the RubyGems ecosystem. When you publish a gem to RubyGems.org, it reads the version directly from this file. Bundler also relies on this version to resolve dependencies in your Rails app's Gemfile—if your gem's version doesn't match what's in the Gemfile, Bundler throws an error. Git tags aren't visible to RubyGems or Bundler, so you can't skip this file.
• Git tags are for your Git version control workflow. They mark a specific commit as a released version, making it trivial to roll back to the exact code that shipped with version 1.0-beta-1.14 (instead of digging through commit history to find it). Tags also make collaboration easier—your team can instantly jump to a released version's code without guessing which commit corresponds to it.

Without the VERSION file, RubyGems won't accept your gem, and Bundler can't manage dependencies. Without Git tags, you lose the ability to reliably map gem versions to their underlying code commits.

Absolutely—you don't have to manually update both the VERSION file and Git tags every time. There are tools to automate this sync:

• Use gems like bump or semver2 to update the VERSION file and create a matching Git tag in one command. For example, bump patch will increment the patch version (e.g., from 1.0.0 to 1.0.1), update the VERSION file, commit the change, and create a v1.0.1 tag automatically.
• Write a simple shell script to handle the sync: update the VERSION file, commit the change, then run git tag v$(grep -oP "VERSION = '\K[^']+" lib/your_gem/version.rb) to create a tag matching the new version.

This way, you only need to trigger one action, and both the VERSION file and Git tag stay in sync.

Not at all—you just need to follow semantic versioning (SemVer) conventions to keep things clear:

• Stable releases (e.g., 1.0.0) get a Git tag and a final VERSION update. These are the versions you want users to depend on.
• Development/pre-release iterations (like your 1.0-beta-1.14 example) belong in the VERSION file but don't necessarily need a Git tag every time. These versions are for testing incremental changes, and you can update the VERSION file as you iterate (e.g., bumping the build number each time you push a change).

The key is: Git tags should correspond to stable, publishable versions, while the VERSION file can track pre-release/development versions to let Bundler pull in the latest changes during testing. This doesn't violate the purpose of either tool—it just uses them for their intended roles.

Here's a streamlined workflow that keeps both tools working together:

1. Development phase:
   • Use a pre-release version in the VERSION file (e.g., 1.1.0-beta-1).
   • Commit changes to your development branch (e.g., develop) without creating Git tags.
   • Let your team pull the latest code with the pre-release version to test changes.
2. Release phase:
   • Update the VERSION file to a stable version (e.g., 1.1.0), commit this change to main.
   • Create a matching Git tag: git tag v1.1.0.
   • Push the tag to your repo: git push origin v1.1.0.
   • Publish the gem to RubyGems: gem build your_gem.gemspec && gem push your_gem-1.1.0.gem.
   • Update the VERSION file to the next pre-release version (e.g., 1.2.0-beta-1) and commit to start the next development cycle.
3. Rollback scenario:
   • If you need to roll back a Rails app to an older gem version, update the Gemfile to specify the old version (e.g., gem 'your_gem', '1.0.0') and run bundle install.
   • If you need to work on the old version's code, run git checkout v1.0.0 to jump directly to the tagged commit.

This workflow ensures the VERSION file and Git tags are always in sync, uses each tool for its intended purpose, and eliminates the confusion of duplicate work.

内容的提问来源于stack exchange，提问作者Michael K Madison