[Beam] Generate rebar3 project scaffold automatically#4387
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When compiling to Erlang/BEAM, Fable now generates a complete rebar3 project structure alongside the .erl files: - .erl files are placed in src/ (project files) and fable_modules/<dep>/src/ (library files), following rebar3 conventions - rebar.config is generated with project_app_dirs pointing to fable_modules/* so rebar3 treats each NuGet dep as a sub-app - Each dep gets src/<app>.app.src and rebar.config (idempotent, regenerated if Fable-generated marker is present) - The root project gets src/<project>.app.src The scaffold is generated after every successful BEAM compilation, making it stateless and watch-mode-safe. Existing rebar.config files without the Fable marker are left untouched (warning emitted). The test runner is updated to use `rebar3 compile` instead of manual erlc invocations, validating the scaffold end-to-end. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…README The beam test runner now uses rebar3 to compile the generated scaffold. Add rebar3-version to the erlef/setup-beam action so it is available on the CI runner, and document Erlang/OTP + rebar3 as requirements. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…ctName, log rebar.config updates
- Extract `Pipeline.Beam.normalizeAppName` as single source of truth for OTP app name normalization; use it in both `deriveDepAppName` and `compilationCycle` (fixes missing `.Trim('_')` at call site)
- Compute `testProjectName` in `Test/Beam.fs` from the project filename instead of hardcoding `"fable_tests_beam"`
- Log `[BEAM] Updated rebar.config` when the generated file changes content (not just on first creation)
- Update CHANGELOG
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…language check first Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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Summary
When Fable compiles F# to Erlang/BEAM, it now generates a complete, immediately buildable rebar3 project structure as a side effect of compilation — no extra steps required.
What's generated
.erlfiles are placed insrc/(project) andfable_modules/<dep>/src/(libraries), following rebar3 conventionsrebar.configwith{project_app_dirs, [".", "fable_modules/*"]}so rebar3 treats each NuGet dep as a sub-appsrc/<project>.app.srcfor the root applicationfable_modules/<dep>/src/<app>.app.srcandrebar.configfor each dependencyDesign
%% Generated by Fable - safe to regeneratemarker are always refreshed; user-writtenrebar.configwithout the marker is left alone (warning emitted)Fable.Logging.0.10.0→fable_logging,fable-library-beam→fable_library_beamTest runner
./build.sh test beamnow usesrebar3 compileinstead of manualerlcinvocations, validating the scaffold end-to-end. All 2247 tests pass.Test plan
dotnet build src/Fable.Cli/Fable.Cli.fsproj— builds cleanly./build.sh test beam— all 2247 tests pass via rebar3🤖 Generated with Claude Code