Functorize worktree access

[subsetpark]

Summary

• add a Worktree.S capability and Worktree.make client for repo-scoped git/worktree effects
• functorize Worktree_setup, Startup_reconciler, and Session_driver over the worktree client
• wire a single WorktreeClient through bin/main.ml and remove app-path process_mgr/repo_root threading for worktree effects

Tests

• dune build
• dune fmt
• env HOME=/private/tmp/onton-empty-home XDG_CONFIG_HOME=/private/tmp/onton-empty-xdg GIT_CONFIG_GLOBAL=/dev/null GIT_CONFIG_NOSYSTEM=1 dune runtest
• pre-commit hook: dune build, dune runtest, format check

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Summary by cubic

Functorized all worktree operations behind a Worktree.S interface and wired a single client through the app, dropping process_mgr/repo_root plumbing across session APIs. This simplifies session flow and makes repo-scoped git actions easier to test and mock.

• Refactors

  • Added Worktree.S and moved worktree operations behind it (create/remove, list/find, hooks, fetch, status).
  • Functorized Worktree_setup, Startup_reconciler, and Session_driver over Worktree.S.
  • Removed process_mgr/repo_root from Session_driver.Make (run, run_long_lived) and updated runner_fiber call sites.
  • Updated bin/main.ml to construct and pass one worktree client; removed ad-hoc threading of process_mgr and repo_root.

• Migration

  • Provide a Worktree.S implementation and pass it to Worktree_setup.Make, Startup_reconciler.Make, and Session_driver.Make.
  • Update calls to Session_driver.run/run_long_lived to remove process_mgr/repo_root.
  • Use Startup_reconciler.Make(...).recover_worktrees; the top-level recover_worktrees was removed.

^{Written for commit ca18634. Summary will update on new commits. Review in cubic}

Summary by CodeRabbit

• Refactor
  • Restructured internal architectural patterns to improve dependency injection and module composition across session management, worktree operations, and startup reconciliation components.

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Project	Deployment	Actions	Updated (UTC)
onton	Ready	Preview, Comment	May 20, 2026 3:57pm

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: cc322209-72fe-4c96-a178-f5bc5309ef08

📥 Commits

Reviewing files that changed from the base of the PR and between 52b43eb and ca18634.

📒 Files selected for processing (9)

• bin/main.ml
• lib/session_driver.ml
• lib/session_driver.mli
• lib/startup_reconciler.ml
• lib/startup_reconciler.mli
• lib/worktree.ml
• lib/worktree.mli
• lib/worktree_setup.ml
• lib/worktree_setup.mli

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📝 Walkthrough

Walkthrough

This PR refactors the runner to eliminate direct process_mgr/repo_root threading by introducing a Worktree.S module abstraction, constructing a concrete worktree client once at startup, and functorizing session execution, startup reconciliation, and worktree setup to accept the injected client, enabling cleaner dependency management throughout the orchestration stack.

Changes

Worktree Abstraction and Module-Based Dependency Injection

Layer / File(s)	Summary
Worktree.S module type and client lib/worktree.ml, lib/worktree.mli	Introduces module type S capturing repo-bound worktree operations (create, remove, query, fetch, rebase, push, hooks, conflict introspection), plus type client = (module S) and make ~process_mgr ~repo_root constructor that packages these operations into a first-class module.
Startup reconciliation with injected worktree client lib/startup_reconciler.ml, lib/startup_reconciler.mli	Refactors Make functor to accept Worktree.S, introduces recover_worktrees_with helper using injected listing, and removes repo_root/process_mgr parameters from reconcile; worktree discovery now unconditionally delegates to the client.
Worktree setup functorization lib/worktree_setup.ml, lib/worktree_setup.mli	Moves resolve_worktree_path and ensure_worktree under Make (W : Worktree.S) functor, removing process_mgr/repo_root parameters and routing creation, status queries, and hook execution through W.
Session driver orchestration refactoring lib/session_driver.ml, lib/session_driver.mli	Functorizes over Worktree.S, removes process_mgr/repo_root threading, and refactors streaming to detect PR numbers in bounded windows and conditionally persist session metadata; updates result handling to override "no-commits" for human-directed operations.
Main runner integration bin/main.ml	Extends Make_fibers to accept Worktree.S, instantiates reconciler and session/setup modules with injected client, and updates all polling, rebase, push, conflict, and delivery paths to call worktree operations through W without process_mgr/repo_root.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~65 minutes

Possibly related PRs

• flowglad/onton#279: Overlaps with lib/session_driver.ml session orchestration refactoring (streaming improvements, telemetry/artifact sink registration, and session UUID handling) that this PR builds upon.
• flowglad/onton#286: Both PRs modify lib/startup_reconciler.ml's Make functor and reconcile wiring; this PR extends that to inject Worktree.S and eliminates process_mgr/repo_root parameters.

Poem

🐰 Hops through the worktree maze,
Dependencies untangled now in cleaner days,
Modules functor-bound with grace,
Each thread a ribbon, finding its place.
The runner dances, lighter, more free—
Abstraction's gift to the codebase, you see! 🌿

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title 'Functorize worktree access' clearly and concisely summarizes the main change: introducing a Worktree.S capability and functorizing modules over it to encapsulate worktree operations, which is the primary objective.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch lift-worktree-into-functor

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[flowglad-review-service]

Code Review: 3 comments

[flowglad-review-service]

Review Summary

This is an infra-class refactor that functorizes worktree operations behind Worktree.S and wires a single client through bin/main.ml. The mechanical plumbing is correct and the intent is clear. Two actionable issues:

1. Dead parameters in session_driver.mli (process_mgr and repo_root still appear in the run/run_long_lived signatures inside Make but are silently ignored in the implementation). These should be removed from the interface to avoid misleading callers.

2. Minor naming inconsistency in startup_reconciler.ml (recover_worktrees_with at module level vs the rest of the codebase convention) — low priority, not a correctness issue.

No correctness bugs, no security issues, no violation of the busy/complete invariant, and no effectful dependencies leaked into lib_core.

Severity	Count
Must-fix	0
Should-fix	2
Note	1

Variant: convergence-v2

Candidates: 3 | Posted: 3 | Suppressed: 0

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3 comments posted · Model: claude-sonnet-4-6 (sonnet) · Tokens: 38683 in / 907 out · Cache: 0 created / 8838 read · Review mode: one-shot

[flowglad-review-service]

Review Summary

This delta introduces the Worktree.S capability interface and functorizes Worktree_setup, Startup_reconciler, and Session_driver over it, wiring a single WorktreeClient through bin/main.ml. The refactor is mechanically correct and clean: process_mgr/repo_root threading is consistently removed from the public interfaces and the make factory correctly captures both values in the returned first-class module. No new correctness, security, or data-loss issues are introduced by this push. The three outstanding comments from round 1 remain live on the PR; no new actionable findings are present in this incremental diff.

Severity	Count
Must-fix	0
Should-fix	0
Note	0

Variant: convergence-v2

Candidates: 0 | Posted: 0 | Suppressed: 0

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0 comments posted · Model: claude-sonnet-4-6 (sonnet) · Tokens: 40893 in / 202 out · Cache: 0 created / 8838 read · Review mode: one-shot