[Content Addressable] Bundler Local Cache and Lockfile

[OughtPuts]

ruby#9733

TL;DR

This PR updates the bundler install flow for locally cached gems to support content addressable gem naming.

Description

This PR builds on the Bundler remote-install support for content-addressed gems.

It writes the gem’s content address and platform to Gemfile.lock, then parses those values back into LazySpecification during a subsequent install. This lets Bundler identify the content-addressed .gem in vendor/cache and install it with bundle install --local, without contacting the remote source again.

The same content-addressed name is used for the installed gem directory in both remote and local installation paths, ensuring lockfile round-trips produce a consistent on-disk layout.

Tests

Updates made to lockfile_parser_spec, content_addressable_spec and ext_spec to cover the changes.

Tophatting

1. Start a local rubygems.org server, that contains a content-addressable gem.
2. Set your gemfile to point to the local server and a content-addressable gem that is available via that server.
3. Run bundle install from the directory that contains your gemfile, using a Ruby version compatible with the content addressable gem.
4. Confirm that the Gemfile.lock contains a content address:

GEM
  remote: http://localhost:3000/
  specs:
    ca_test_harriet (0.3.5-arm64-darwin-23) d26b82f6

PLATFORMS
  arm64-darwin-23

DEPENDENCIES
  ca_test_harriet (= 0.3.5)

CHECKSUMS
  ca_test_harriet (0.3.5-arm64-darwin-23)

BUNDLED WITH
  4.1.0.dev

5. Remove any locally installed gem files other than the cached files (normally in the /cache/ directory)
6. Re-run bundle install --local. Confirm the content addressable gem installs correctly still and that it uses the correct content addressable name.

I've performed this tophat locally and it's all looking good! ✅

[Copilot]

Pull request overview

This PR adds Bundler/RubyGems support for content-addressable gem artifacts end-to-end, including compact-index v2 test infrastructure, lockfile encoding/parsing, and ensuring local cache resolution works with content-addressed filenames.

Changes:

• Extend specification/name tuple objects to carry content_address, and update resolution & lockfile serialization/parsing accordingly.
• Add Artifice compact-index v2 helpers to model content-addressable gems in specs, including platform metadata injection.
• Add/adjust specs to cover lockfile formatting/parsing and local-cache round-trips for content-addressable gems.

Reviewed changes

Copilot reviewed 28 out of 28 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
spec/support/builders.rb	Build helper now supports producing content-addressable gem files (Ruby ABI–scoped).
spec/support/artifice/helpers/compact_index.rb	Checksum calculation updated to use spec.full_name gem filenames.
spec/support/artifice/helpers/compact_index_v2.rb	New compact-index v2 Artifice helper with content-addressable gem support and metadata injection.
spec/support/artifice/helpers/compact_index_cooldown.rb	Removed (superseded by v2 helper).
spec/support/artifice/compact_index_v2.rb	New Artifice activation entrypoint for the v2 helper.
spec/support/artifice/compact_index_cooldown.rb	Removed (tests now use compact_index_v2).
spec/other/ext_spec.rb	Add coverage for Gem::NameTuple#lock_name and Bundler::LazySpecification#to_lock with content addresses.
spec/install/gemfile/content_addressable_spec.rb	New integration specs for content-addressable install, caching, and lockfile round-trips.
spec/install/cooldown_spec.rb	Switch cooldown tests to use the compact-index v2 Artifice setup.
spec/bundler/remote_specification_spec.rb	Rename “platform” to “suffix” in test setup and add content-address expectation coverage.
spec/bundler/override_spec.rb	Ensure overrides stubs include content_address.
spec/bundler/lockfile_parser_spec.rb	Add parsing coverage for lockfile lines with a trailing content address token.
spec/bundler/endpoint_specification_spec.rb	Add coverage for CA suffix handling via platform metadata and remote fetching behavior.
lib/rubygems/specification.rb	Include content_address in Specification#name_tuple.
lib/rubygems/safe_marshal.rb	Permit Gem::NameTuple to safely marshal/unmarshal @content_address.
lib/rubygems/name_tuple.rb	Add content_address field on Gem::NameTuple.
lib/bundler/stub_specification.rb	Propagate content_address when building StubSpecifications.
lib/bundler/source/rubygems.rb	Preserve content address when swapping remote specs after download.
lib/bundler/rubygems_integration.rb	Populate spec content_address from Gem::Package when available.
lib/bundler/rubygems_gem_installer.rb	Call RubyGems’ content-address assignment hook when supported.
lib/bundler/rubygems_ext.rb	Compatibility shims for older RubyGems plus lock name behavior for content-addressed tuples.
lib/bundler/resolver.rb	De-dupe resolved specs including content_address to avoid collapsing distinct CA variants.
lib/bundler/remote_specification.rb	Add content_address and include it in full_name when applicable.
lib/bundler/match_platform.rb	Prefer compatible content-addressable candidates when available.
lib/bundler/lockfile_parser.rb	Parse trailing content-address token on spec lines and propagate into LazySpecification.
lib/bundler/lazy_specification.rb	Track content_address, include it in full_name, and emit it in lock output.
lib/bundler/fetcher.rb	Treat the 3rd token as a “suffix” and pass through to endpoint/remote specification constructors.
lib/bundler/endpoint_specification.rb	Add CA suffix parsing via metadata-provided platform and fetch remote specs using CA suffix when present.

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[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

[OughtPuts]

This allows us to correctly find the CA gem spec by either the full_name OR the lock_name after the recent naming changes, when storing the checksum.

[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated no new comments.