fix

name	fix
description	Repair a broken state. Routes to the fast one-fix-per-iteration loop with auto-revert (fix, default) or the scientific-method hypothesis loop (investigate). Use when: 'fix all errors', 'make tests pass', 'fix the build', 'debug this', 'investigate this failure'.
argument-hint	[fix|investigate] (fix: [from-debug] [--scope <glob>] [--guard <cmd>] [--category test|type|lint|build] [Iterations: N])
requires	{"binaries":["fno >= 0.1","git >= 2.0"]}

Fix

One verb on a broken state. /fix routes between fast repair and methodical diagnosis.

Mode	What runs	Use when
fix (default)	fast one-fix-per-iteration loop, auto-revert on regression	you know roughly what is broken and want it green
investigate	scientific-method hypothesis loop (BDD criteria + failing repro)	the cause is unknown and you need to find it first

This is a router. It parses the first argument as a mode, announces the resolved mode, then either runs the default loop here or loads the investigate reference and follows it. It never calls another skill at runtime (it dispatches the tournament-debugger via the Task/Agent tool and loads the investigate flow via Read).

Step 0: Location preflight (before any write)

/fix writes code. Before resolving the mode, consult the shared location verdict (the SAME one /target and /do use, so the canonical-main rule never drifts). Resolve the plugin root portably so the helper is found on non-Claude surfaces too (where CLAUDE_PLUGIN_ROOT is unset and the project checkout is NOT the abilities plugin): try CLAUDE_PLUGIN_ROOT, then CODEX_PLUGIN_ROOT, then the persisted ~/.fno/plugin-root pointer (written by session-start.sh), then the git root.

PLUGIN_ROOT="${CLAUDE_PLUGIN_ROOT:-${CODEX_PLUGIN_ROOT:-$(cat "$HOME/.fno/plugin-root" 2>/dev/null || git rev-parse --show-toplevel 2>/dev/null)}}"
LOC_HELPER="$PLUGIN_ROOT/hooks/helpers/check-impl-location.sh"
[[ -f "$LOC_HELPER" ]] && bash "$LOC_HELPER" || echo "verdict=ok"

If the output carries verdict=canonical-protected AND TARGET_LOCATION_OK is not main-acknowledged, REFUSE: do not resolve the mode, do not write. Name the branch (from the branch= line) and print the exact escape, then stop:

/fix refused: canonical checkout on '<branch>' (sibling terminals share .fno/).
  worktree:  git worktree add ~/conductor/workspaces/<repo>/<slug> -b feature/<slug>
  branch:    git checkout -b feature/<slug>
  override:  re-run with TARGET_LOCATION_OK=main-acknowledged

Otherwise (verdict=ok, a linked worktree, or the helper absent) continue to Step 1.

Step 1: Resolve the mode (ALWAYS announce it)

Parse the first argument token:

• investigate -> mode is investigate. Print running investigate (hypothesis loop). Go to "Investigate mode".

• fix -> mode is fix (explicit). Print running fix (repair loop). Consume the token; the rest are fix's arguments. Go to "Fix mode".

• empty, from-debug, a --flag, or Iterations: N -> mode is fix (default). Print running fix (default). Keep the token as fix's own argument. Go to "Fix mode".

• any other bare non-flag word -> this is an unknown mode (likely a typo). Do NOT default, do NOT guess. Print:

  unknown fix mode: '<token>'
  valid modes: fix (default), investigate
  

  and stop with a non-zero result. This is the locked router contract: an unknown non-empty mode never silently falls through.

Investigate mode

Load investigate.md and execute it in full, in this context. That reference is the canonical scientific-method debugging loop: define acceptance criteria, prove the bug with a failing reproduction, then test one falsifiable hypothesis per iteration. When it finishes with confirmed findings, the natural next step is the default repair loop - /fix from-debug consumes those findings in severity order.

Fix mode (default)

Repair a broken state iteratively until the error count reaches zero or the loop exhausts its budget.

Reference Materials

Load these references as needed:

• references/iteration-loop.md
• references/verification-patterns.md

Defaults

• Default bounded run: Iterations: 15
• Output root: fix/{YYMMDD}-{HHMM}-{slug}/

Interactive Setup

If the user did not provide explicit target information, auto-detect failures first and then ask in one batched AskUserQuestion call:

1. what to fix
2. guard command
3. scope
4. iteration mode

The first question should summarize the detected failure counts.

Process

1. Detect

Use verification-patterns.md to identify:

• build failures
• critical/high debug findings
• type errors
• test failures
• lint errors
• warnings

If from-debug modifier is set, read the latest debug/*/findings.md (or .fno/debug/*.md) and populate the queue from confirmed bugs first.

Nothing-to-fix exit (EDGE). If detection finds zero failures across every category (clean working tree, no failing test, no debug findings), report nothing to fix and exit cleanly. Do NOT enter the iteration loop on an empty queue.

2. Prioritize

Fix order:

1. build
2. critical/high bugs
3. type
4. test
5. medium/low bugs
6. lint
7. warnings

3. Iterate

Load iteration-loop.md and run this atomic loop:

1. pick the highest-priority unfixed item
2. read the relevant code and error context
3. make one focused fix
4. git commit before verify
5. re-run detection to compute delta
6. run the guard command if provided
7. keep, revert, or rework
8. log to fix-results.tsv

Maximum rework attempts per item: 2. After that, add it to the blocked list and continue.

4. Summary

Write:

• fix/{YYMMDD}-{HHMM}-{slug}/fix-results.tsv
• fix/{YYMMDD}-{HHMM}-{slug}/summary.md

summary.md must include:

• baseline error count
• fixed count by category
• remaining errors
• blocked items
• every reverted fix and why it reverted (regression / non-positive delta), so an auto-reverted attempt is reported, not silently dropped
• suggestion to run a code review skill if available (e.g., /review), or run the project's test/lint/build commands to verify fixes

Category Strategies

Category	Strategy
build	fix the exact import, syntax, or config break
type	proper types, null handling, generics, explicit narrowing
test	fix implementation, not the test, unless the test is provably wrong
lint	satisfy the rule, do not suppress it
bug	apply the concrete fix implied by the debug evidence

Anti-Pattern Blocklist

Discard and re-queue any fix that uses:

• @ts-ignore
• eslint-disable
• # type: ignore
• # noqa
• any used only to silence type errors
• deleted or skipped failing tests
• empty catch blocks
• hardcoded values chosen only to satisfy one test

Decision Rules

• Keep when delta > 0 and the guard passes
• Rework when delta > 0 but the guard fails
• Revert when delta <= 0
• Revert immediately on regression, and record the revert in the summary

Composite Metric

fix_score = reduction * 0.60 + guard_health * 0.25 + quality * 0.15