jmove/docs/SKILL.md
loki5512344 f8004e669b
feat(check): java public-class ⇄ file-name mismatch — layout finding with a ready jmove mv repair
- parser::java::class_name: exactly-one-public-top-level-type rule
  (package-info/module-info and 0-or-2-public files skipped)
- check gains name_mismatches[] (JSON, omitted when clean) + human lines;
  exit 2 covers both kinds; fix engine untouched by design — a file rename
  is not a byte edit, and mv keeps the FQN so no imports change
- output split into output/{mod,check} to stay under the 250-line rule
- e2e: reports Bad.java, stays quiet on Good.java, suggested rename makes
  check pass and preserves the file bytes
2026-09-15 19:05:54 +02:00

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# jmove skill (for AI agents)
## What this tool does
Moves or renames source files — or whole directories of them — inside a
project and updates every import statement referencing them. Never breaks imports. Supported: TypeScript,
JavaScript, Java (package declaration + all importers + the file move are
kept in sync); Python/Go on the roadmap. Single binary, no LSP needed.
## When to use
- The user asks to move/rename/reorganize source files or packages.
- You refactored a directory layout and imports now point at nothing.
- You need to verify the project has no broken imports (`check`).
## Commands
### mv — move a file and rewrite its importers
```
jmove mv <source> <target> [--root DIR] [--source-root DIR] [--dry-run] [--json] [--no-git]
```
Always run `--dry-run` first and confirm the change set looks right.
Moving onto an existing path fails with `TARGET_EXISTS` — choose another
target (Phase 1 has no overwrite mode).
Directory moves: `mv <dir> <target>` relocates every indexed file under
`<dir>` mirrored under `<target>` in one atomic batch. `--json` adds
`moved_files[]` (from/to per file) and `left_behind[]` — real files under
`<dir>` that are not indexable and deliberately stay where they are.
Emptied source directories are pruned; a directory with leftovers is not.
A source that is nested in its own target fails with `PLAN_REJECTED`.
Git integration: inside a git repository, a tracked file is renamed with
`git mv` so the rename is staged (history-preserving `git log --follow` /
`git diff -M` work). Untracked files, non-repositories and `--no-git`
fall back to a plain filesystem rename. The import rewrites land in the
working tree unstaged either way — stage or commit them yourself.
`--json` reports the choice as `moved_via` (`"git"`/`"fs"`) and, on a
dry-run, `would_move_via`.
### check — find broken imports and Java layout errors
```
jmove check [--root DIR] [--json]
```
Run after any move (or any edit) to validate project consistency. Reports
broken relative imports and Java files whose single public type is named
differently from the file (each finding carries the exact `jmove mv` that
renames it; exit code 2 covers both kinds).
### fix — auto-repair import problems
```
jmove fix [--root DIR] [--rule ID] [--dry-run] [--json]
```
Runs the deterministic rules over the whole project and applies the
repairs through the same atomic engine as `mv` (dry-run diff, rollback,
exit codes). Current Java rules: `java/unused-import` (deletes single-type
imports whose name is provably unreferenced), `java/missing-import`
(inserts the import of a project class used by simple name — unique FQN
candidate required) and `java/import-order` (Google style: statics first,
then single-type, ASCII-sorted, duplicates dropped). TS/JS:
`ts/unused-import` deletes whole statements whose every bound name is
unreferenced; mixed statements (one name live) stay untouched because ESM
imports carry module side effects, so partial specifier surgery is
deliberately off. Unknown `--rule`
fails with `INVALID_ARGUMENT` and lists the known ids. A candidate the
engine cannot prove safe is reported with `"applied": false` and a
`candidates` array of FQN options — resolve it yourself (pick one, add
the import) and re-run; `fix` never guesses. When two rules want the same
bytes (order rewrite vs an unused deletion), the urgent rule applies and
the other is deferred (`"applied": false`, "skipped") — re-run `fix`
until it reports "nothing to change" (converges in 2–3 runs).
Recommended: `fix --dry-run --json`, inspect `files[].fixes[]`
(`rule`, `line`, `message`, `applied`, optional `candidates`), then apply
without `--dry-run`. For Java projects the practical loop is: `mv` →
`fix` → `fix` again if anything was "skipped" → `check`.
## Java specifics
- Moving a `.java` file rewrites three coordinated edits: its own
`package` declaration, every `import <fqn>` naming the class (static
member imports keep their member suffix) and the physical move.
- The target must be a `.java` path under the same source root
(`src/main/java`, `src`, …) and its directory maps to the new package.
Anything else exits `1` with code `PLAN_REJECTED`.
- A class in the default package (no `package` declaration) can only be
renamed inside its directory.
- `check` never reports unresolved Java imports (jdk, third-party,
`pkg.*`) as broken — they are external by design, like TS bare
specifiers.
- Monorepos with duplicate packages (`guava` vs `android/guava` under one
`--root`): the same FQN exists in parallel trees, so resolution picks the
sorted-first copy and a move rewrites the wrong files. Pass the global
`--source-root DIR` to index (and fix/move) only that subtree; each tree
is then self-contained and correct. Without the flag behavior is
unchanged; `--source-root` on a non-directory exits 1.
## Recommended agent workflow
1. `jmove mv <src> <target> --dry-run --json` — preview.
2. Inspect `affected_files`; if unexpected, abort and ask the user.
3. `jmove mv <src> <target> --json` — apply (atomic, rolls back on error).
4. Java moves: `jmove fix --json` — heal bare same-package references
left behind by the move (they break `javac` otherwise).
5. `jmove check --json` — verify nothing is broken.
## Output format (--json)
Every response: `{ "status": "ok" | "dry_run" | "error", "operation": "...", ... }`.
Errors carry a stable `code` (`TARGET_EXISTS`, `SOURCE_NOT_FOUND`, ...)
and a `hint` describing the next action. On success, `mv` reports
`changed_files` with line-level `old`/`new` import diffs and counters
(`moved`, `updated_imports`).
## Exit codes
- `0` — success
- `1` — operation failed (read `--json` error or stderr)
- `2` — `check` found broken imports or Java name mismatches
## Rules of use
- Never run `mv` without a prior `--dry-run` in the same session.
- After every successful `mv`, run `check`; treat exit code `2` as
a failed refactor.