feat: add experimental arf headless subcommand for terminal-free IPC operation#119
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feat: add experimental arf headless subcommand for terminal-free IPC operation#119
arf headless subcommand for terminal-free IPC operation#119Conversation
Add a new `arf headless` subcommand that starts R with an IPC server but without the interactive REPL (reedline). This enables IPC testing on Windows CI where ConPTY cursor::position() is problematic, and supports AI-agent-only use cases where no terminal is needed. The headless mode: - Initializes R with the same flags as the REPL (vanilla, no-environ, etc.) - Starts the IPC server automatically (no --with-ipc flag needed) - Polls for IPC requests and R events in a simple loop - Exits on Ctrl+C Integration tests use `arf headless` + `arf ipc eval` end-to-end, requiring only std::process::Command (no PTY). Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
The headless handler was ignoring the visible parameter, always using silent capture. Now visible=true passes through to start_ipc_capture, so output is written to the headless process's stdout/stderr as well as being returned in the JSON-RPC response. Also add test verifying visible output appears on the server side and silent output does not. Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
…nput error handling - Extract shared R argument-building logic into RArgsBuilder struct, used by both Cli::r_args() (REPL) and run_headless(). Eliminates the duplicated headless_r_args static method. - Simplify run_headless() from 11 parameters to 4 by passing RArgsBuilder directly. Removes the clippy too_many_arguments allow. - Return accepted=false from headless user_input when eval_string fails, so IPC clients can detect evaluation failures. Addresses roborev review 419 findings. Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
Add a `shutdown` JSON-RPC method that triggers graceful shutdown of headless mode. The method is handled directly on the server thread (no main thread round-trip needed) by setting the shared shutdown flag. In REPL mode, shutdown returns METHOD_NOT_FOUND since the REPL has its own exit mechanisms (:quit, Ctrl+D, q()). Also adds `arf ipc shutdown --pid <PID>` CLI subcommand and updates the headless help text to reference it. Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
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Pull request overview
Adds a headless execution mode to arf-console so R + the IPC server can run without a terminal/REPL, enabling cross-platform (notably Windows CI) IPC integration testing and adding a graceful shutdown path for headless sessions.
Changes:
- Add
arf headlesssubcommand that runs R + IPC server without reedline/terminal. - Add JSON-RPC
shutdownmethod plusarf ipc shutdownclient command. - Refactor R init argument construction into a shared
RArgsBuilder, and add new headless end-to-end integration tests + updated CLI completion/help snapshots.
Reviewed changes
Copilot reviewed 15 out of 16 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| crates/arf-console/tests/headless_tests.rs | New terminal-free integration tests covering headless IPC behavior, including shutdown. |
| crates/arf-console/src/main.rs | Wires headless subcommand to a new run_headless event loop and hooks IPC shutdown + Ctrl+C. |
| crates/arf-console/src/cli.rs | Adds Headless subcommand, ipc shutdown, and introduces RArgsBuilder for shared R arg construction. |
| crates/arf-console/src/ipc/mod.rs | Adds headless shutdown flag + headless polling/processing path; updates capture call signature usage. |
| crates/arf-console/src/ipc/server.rs | Implements shutdown JSON-RPC method (headless-only) handled directly on the server thread. |
| crates/arf-console/src/ipc/client.rs | Adds cmd_shutdown for arf ipc shutdown. |
| crates/arf-console/src/ipc/protocol.rs | Introduces ShutdownResult protocol type. |
| crates/arf-console/src/ipc/capture.rs | Extends capture to optionally “tee” output to process stdout/stderr when visible is true. |
| crates/arf-console/src/snapshots/arf__cli__tests__help_long.snap | Updates CLI help snapshot to include headless. |
| crates/arf-console/src/snapshots/arf__cli__tests__completions_*.snap | Updates shell completion snapshots for headless and ipc shutdown. |
| crates/arf-console/Cargo.toml | Adds ctrlc dependency for headless Ctrl+C handling. |
| Cargo.toml | Adds workspace dependency entry for ctrlc. |
| Cargo.lock | Locks ctrlc and its transitive deps. |
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- Fix headless_tests.rs module doc: "session file discovery" → actual stderr monitoring mechanism - Improve cmd_shutdown error handling: treat missing/non-accepted result as error with non-zero exit - Add test_ipc_shutdown_rejected_in_repl: verify shutdown returns METHOD_NOT_FOUND in REPL mode Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>
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arf headless subcommand for terminal-free IPC operationarf headless subcommand for terminal-free IPC operation
This was referenced Mar 28, 2026
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Summary
arf headlesssubcommand that starts R + IPC server without interactive REPL (no reedline/terminal needed)shutdownIPC method andarf ipc shutdownCLI for graceful headless terminationRArgsBuilderto deduplicate R argument-building logic between REPL and headless modesMotivation
Windows CI cannot run IPC tests because ConPTY's
cursor::position()is incompatible with reedline. Headless mode eliminates terminal dependency entirely, enabling cross-platform IPC testing with juststd::process::Command.Test plan
--vanillaflagcargo clippyclean (no warnings)🤖 Generated with Claude Code