Data Safety Rules + Extensible Rule System (PR #131 Part 2)

[ahundt]

PR 131 Part 2: Data Safety Rules + Extensible Rule System

Branch: feat/data-safety-rules-v2 | Base: master (stacks on Part 1)
Tests: 673 pass | Closes: #115
Split from: PR #131
New deps: trash = "5", serde_yaml = "0.9"
PR: #157

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Context

Addresses item 2 from FlorianBruniaux's split request:

Data safety rules (rm->trash, git reset --hard->stash) + rtk.*.md files -- this adds the trash and which deps

Depends on PR 1 for the hook engine (safety.rs integrates into hook.rs and exec.rs). Parallel to PR 3 (Gemini) -- zero file overlap.

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Merge Sequence

After PR 1 merges: retarget feat/data-safety-rules-v2 -> master, then merge. Can merge before or after PR 3.

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Summary

11 safety rules intercept destructive commands and make them recoverable.

Impact: Prevents ~20-50K token costs per data loss incident (investigate damage → restore/rewrite → regenerate → debug differences).

Rules

Pattern	Action	Rewrite
rm	trash	Move to OS trash instead of permanent delete
git reset --hard	rewrite	Stash first, then reset
git checkout . / git checkout --	rewrite	Stash first, then checkout
git clean -f/-fd/-df	rewrite	Stash untracked first, then clean
git stash drop	rewrite	git stash pop (recoverable)
cat / head / sed	block	Suggest Read/Edit tools instead

Conditional rules (git reset --hard, git checkout) use when: has_unstaged_changes -- only fire when uncommitted changes exist.

Opt-out: RTK_SAFE_COMMANDS=0 disables safety rules. RTK_BLOCK_TOKEN_WASTE=0 allows cat/head/sed.

Extensible rtk.*.md rule files

Rules are markdown with YAML frontmatter. 11 built-in rules compile into the binary via include_str!(). Users override or extend by placing files in .rtk/, .claude/, .gemini/, or ~/.config/rtk/:

---
name: rm-to-trash
patterns: [rm]
action: trash
redirect: "trash {args}"
env_var: RTK_SAFE_COMMANDS
---
Safety: Moving to trash instead of permanent deletion.

Priority: CLI paths > project-local dirs > global dirs > built-in defaults. Same-name rules override by priority.

User custom rule example -- ~/.config/rtk/rtk.safety.chmod-777.md:

---
name: chmod-777
patterns: ["chmod -R 777", "chmod 777"]
action: warn
when: "git rev-parse --is-inside-work-tree 2>/dev/null"
env_var: RTK_SAFE_COMMANDS
---
Warning: chmod 777 grants full access. Consider chmod 755 or 644 instead.

Config system expansion

src/config.rs (125 lines) replaced by src/config/ module (3 files, 2419 lines):

• mod.rs -- Config struct with precedence chain, CRUD operations
• rules.rs -- Rule loading, regex matching, try_remap() alias expansion
• discovery.rs -- Walk-up ancestor directory discovery

New commands: rtk config list/get/set/unset/create/export-rules

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Changes

24 files changed (+3535, -148)

New: src/cmd/safety.rs (538 lines, 30 tests), src/cmd/trash_cmd.rs (76 lines, 4 tests), src/config/{mod,rules,discovery}.rs, 11 rule files in src/rules/

Modified: src/cmd/mod.rs (+safety, +trash_cmd), src/cmd/hook.rs (restore safety integration), src/cmd/exec.rs (restore safety dispatch), src/main.rs (+Config commands), Cargo.toml (+trash, +serde_yaml)

Deleted: src/config.rs (replaced by src/config/ module)

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Review Guide

Focus areas:

1. src/cmd/safety.rs + src/rules/*.md -- Rule matching and rewriting
2. src/config/rules.rs + discovery.rs -- Rule loading, precedence, override semantics
3. src/cmd/hook.rs + exec.rs -- Safety integration points

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Not Included (Future)

• Extended safety rules: sudo rm, docker rm, kubectl delete with confirmations
• Analytics on which rules fire most often
• Additional built-in predicates beyond always and has_unstaged_changes

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Test Plan

• cargo test -- 673 tests pass (safety:30, trash:4, rules:15, discovery:8, +3 restored hook tests)
• echo '{"tool_input":{"command":"rm file"}}' | cargo run -- hook claude -- rm rewritten
• echo '{"tool_input":{"command":"cat file.txt"}}' | cargo run -- hook claude -- cat blocked (exit 2)
• cargo run -- hook check "git clean -fd" -- stash prepended
• RTK_SAFE_COMMANDS=0 cargo run -- hook check "rm file" -- opt-out works
• cargo run -- hook check "catalog show" -- NOT blocked (catalog != cat)
• cargo run -- config list -- CRUD works

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Related PRs (Split from PR #131)

Part	PR	Description
1	#156	Hook Engine + Chained Commands
2	#157	Data Safety Rules (this PR)
3	#158	Gemini CLI Support

Merge order: Part 1 first → retarget Parts 2 & 3 to master → merge in any order

[ahundt]

@pszymkowiak I saw a pending problem tag added to this one is there a particular technical issue? I've been running it without issue myself.