refactor(protoc): migrate to protocompile experimental compiler for Edition 2024

[Kybxd]

Why

Protobuf Edition 2024 is not understood by bufbuild/protocompile's stable Compiler. To unblock Edition 2024 schemas, we follow the same path Buf itself took in buf v1.69.0 and switch the internal protoc wrapper to protocompile's experimental compiler, which has Edition 2024 support.

What changes vs. the stable compiler

The experimental compiler exclusively consumes source files via source.Opener. It no longer accepts pre-compiled FileDescriptors through protoregistry.GlobalFiles — which is how the stable compiler used to pick up tableau/protobuf/*.proto and buf/validate/validate.proto. We need a new mechanism to make those imports resolvable at compile time.

How

Expose the required .proto sources through go:embed and feed them to protocompile via a custom fs.FS:

Import path	Source of truth	Vendored?
tableau/protobuf/tableau.proto	proto/tableau/protobuf/tableau.proto (embedded via tableauprotobuf.FS)	no
tableau/protobuf/wellknown.proto	proto/tableau/protobuf/wellknown.proto (embedded via tableauprotobuf.FS)	no
buf/validate/validate.proto	buf export of buf.build/bufbuild/protovalidate pinned in buf.lock	yes, under internal/x/xproto/protoc/embedded/

Standard imports (google/protobuf/*) continue to be served by source.WKTs and need no embedding.

Single source of truth for tableau protos

A new proto/tableau/protobuf/embed.go exposes tableauprotobuf.FS (//go:embed tableau.proto wellknown.proto, matching buf.yaml's top-level-only scope), and internal/x/xproto/protoc/embed.go composes it with the vendored buf/validate/ tree behind a small layeredFS that routes tableau/protobuf/* reads to tableauprotobuf.FS and everything else to the embedded buf-validate export. This means the compiler always sees the exact same tableau proto text that ships in proto/tableau/protobuf/, with no risk of a stale second copy.

Refresh workflow for protovalidate

A go:generate directive in embed.go invokes gen_embedded.sh, which:

1. Wipes embedded/ and recreates embedded/buf/validate/.
2. Reads the protovalidate commit out of buf.lock and forwards it to buf export buf.build/bufbuild/protovalidate:<commit>.

⚠️ buf export <remote-module> does not consult the workspace's buf.lock — that file only governs intra-workspace transitive resolution. Without an explicit commit suffix, buf export would pull the latest published commit. The script reads the commit from buf.lock so the vendored copy stays in sync automatically.

Why is embedded/ checked into version control?

So that downstream consumers of go install github.com/tableauio/tableau/cmd/tableauc@latest can build without buf installed and without running go generate — proxy.golang.org only packages git-tracked files.

Upgrading protovalidate

buf dep update          # bumps buf.lock
go generate ./...       # refreshes embedded/buf/validate/
git add -A && git commit

Diff summary

7 files changed, mostly the vendored buf/validate/validate.proto (~5.1k lines):

• internal/x/xproto/protoc/compiler.go — switch to experimental compiler, wire source.Opener against the layered fs.FS.
• internal/x/xproto/protoc/embed.go — go:embed for buf/validate/, layeredFS, and refresh-workflow docs.
• internal/x/xproto/protoc/gen_embedded.sh — refresh script driven by buf.lock.
• internal/x/xproto/protoc/embedded/buf/validate/validate.proto — vendored protovalidate schema.
• proto/tableau/protobuf/embed.go — new tableauprotobuf.FS exposing this repo's own proto sources.
• go.mod / go.sum — protocompile experimental dep.

[codecov]

Codecov Report

❌ Patch coverage is 60.81081% with 29 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.42%. Comparing base (1c5fee6) to head (017b7ce).

Files with missing lines	Patch %	Lines
internal/x/xproto/protoc/compiler.go	58.46%	18 Missing and 9 partials ⚠️
internal/x/xproto/protoc/embed.go	77.77%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #404      +/-   ##
==========================================
- Coverage   75.60%   75.42%   -0.19%     
==========================================
  Files          88       89       +1     
  Lines        9527     9565      +38     
==========================================
+ Hits         7203     7214      +11     
- Misses       1749     1767      +18     
- Partials      575      584       +9     

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[github-actions]

The latest Buf updates on your PR. Results from workflow Buf CI / buf (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	✅ passed	Jul 13, 2026, 12:06 PM