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Split app/mod.rs

Status: Open — Phase 2, confirmation needed

Problem

Section titled “Problem”

src/app/mod.rs is now 2767L total — more than double the 1243L at the original analysis (+123% growth). It is the second-largest file in the codebase after runtime/launch.rs. Nearly all production code is the run() dispatch function with a giant match on CLI commands, but the file has accumulated substantial new command handling, error recovery, and test coverage.

src/app/context.rs (1466L) has also grown and now contains significant instance management, workspace resolution, and Docker interaction logic.

Proposed split

Section titled “Proposed split”
src/app/
  mod.rs           ← re-exports, pub fn run() dispatcher (~80L)
  dispatch.rs      ← the giant match on cli::Command (~700L)
  workspace_cmd.rs ← workspace subcommand handlers (~150L)
  config_cmd.rs    ← config subcommand handlers (~100L)
  load_cmd.rs      ← load/hardline/eject command handlers (new — extracted from dispatch)
  instance_cmd.rs  ← instance management commands (new — instance recovery/purge flows)

Note: src/app/context.rs already implements the impl-extension pattern and stays as-is, though it may need its own split analysis if it continues growing.

Duplication found

Section titled “Duplication found”
  • app/mod.rs contains its own FakeOpWriter (stripped version) that duplicates the fuller one in src/workspace/token_setup.rs. Should use a shared test utility.
  • 4 inline format!("{name}-dind") / format!("{name}-net") derivations that should use a shared naming helper.
  • fake_runner_with_running helper is near-identical to one in console/manager/input/save.rs but with a subtle trailing-newline difference — potential copy-paste bug.

What needs confirmation

Section titled “What needs confirmation”
  • Whether run() stays in mod.rs or also moves to dispatch.rs
  • The exact boundary between dispatch.rs and workspace_cmd.rs (some workspace handling is interleaved in the dispatch match)
  • Whether load_cmd.rs and instance_cmd.rs are worth separate files or should stay in dispatch.rs
  • Whether context.rs (1466L) also needs splitting or is manageable at its current size

Auditability gain

Section titled “Auditability gain”

To audit “does jackin workspace create correctly validate the workdir?”, a reviewer reads workspace_cmd.rs instead of scanning ~2700L of mixed-command dispatch.

Section titled “Recommended priority”

Split first among Phase 2 targets — it has the highest growth rate (+123%), pure dispatch structure (lowest risk), and its split will establish patterns for the remaining file splits.

Section titled “Related files”