Agent Skills: srgn CLI

srgn CLI

Overview

Use this skill to convert user intent into precise srgn commands with safe defaults. Focus on CLI workflows for search, transformation, scoped migrations, and lint-like checks.

Workflow Decision Tree

1. Classify the request.
   • Search only: no content changes expected.
   • Transform in stream: stdin/stdout pipeline usage.
   • Transform files: in-place updates over globs.
2. Identify scope strategy.
   • Regex scope only.
   • Language scope only.
   • Combined language + regex scope.
   • Custom tree-sitter query scope.
3. Identify action strategy.
   • Replacement (positional replacement argument after --).
   • Composable actions (--upper, --lower, --titlecase, --normalize, --symbols, --german).
   • Standalone actions (-d, -s).
4. Apply safety controls.
   • Prefer --dry-run for file operations.
   • Keep globs quoted.
   • Add --fail-no-files when missing files should fail CI.
5. Choose output mode.
   • Human-readable (default tty).
   • Machine-readable (--stdout-detection force-pipe).
6. Validate behavior.
   • Confirm expected match count.
   • Confirm no out-of-scope edits.
   • Re-run with stricter scope if needed.

Safety Protocol

1. Default to non-destructive behavior first.
   • Prefer stdin-based or search-mode examples before in-place rewrites.
2. For file edits, require preview path.
   • Use --dry-run first.
   • Then run the same command without --dry-run only after confirmation.
3. Protect shell parsing boundaries.
   • Quote regex.
   • Quote globs: --glob '**/*.py'.
   • Use -- before replacement values.
4. --glob accepts exactly one pattern (cannot repeat).
   • Glob syntax: *, ?, [...], ** only. No {a,b} brace expansion.
   • For multiple files: broader glob + --dry-run, or per-file via fd: fd -e <ext> --strip-cwd-prefix -x srgn --glob '{}' --stdin-detection force-unreadable [OPTIONS] [PATTERN]
5. Use the narrowest scope that solves the task.
   • Prefer language scope + anchored regex over broad regex-only replacement.
6. Treat -d and -s as high-risk operations.
   • Always provide explicit scope for them.

Command Construction Template

Use this template when building commands:

srgn [LANGUAGE_SCOPE_FLAGS...] [GLOBAL_FLAGS...] [ACTION_FLAGS...] [SCOPE_REGEX] -- [REPLACEMENT]

Build incrementally:

1. Scope first.
   • Example: --python 'imports'
2. Regex filter second.
   • Example: '^old_pkg'
3. Action third.
   • Replacement: -- 'new_pkg'
   • Or composable flag: --upper
4. File mode flags fourth (if needed).
   • --glob '**/*.py' --dry-run
5. CI behavior last.
   • --fail-any or --fail-none

High-Value Task Recipes

1. Rename module imports in Python only:

srgn --python 'imports' '^old_pkg' --glob '**/*.py' --dry-run -- 'new_pkg'

2. Convert print calls to logging in Python call-sites only:

srgn --python 'function-calls' '^print$' --glob '**/*.py' --dry-run -- 'logging.info'

3. Rename Rust use prefixes without touching strings/comments:

srgn --rust 'uses' '^good_company' --glob '**/*.rs' --dry-run -- 'better_company'

4. Remove C# comments only:

srgn --csharp 'comments' -d '.*'

5. Search for Rust unsafe language keyword usage only:

srgn --rust 'unsafe'

6. Fail CI if undesirable pattern appears in Python docstrings:

srgn --python 'doc-strings' --fail-any 'param.+type'

7. Force machine-readable output for downstream parsers:

srgn --python 'strings' --stdout-detection force-pipe '(foo|bar)'

8. Preview multi-file changes with deterministic ordering:

srgn --typescript 'imports' '^legacy-lib' --glob 'src/**/*.ts' --sorted --dry-run -- 'modern-lib'

For broader, categorized examples, load references/cli-cookbook.md.

Failure and Debug Playbook

1. No matches when matches are expected.
   • Verify language scope and prepared query name.
   • Remove regex temporarily to test scope alone.
   • Add --stdout-detection force-pipe to inspect exact matched columns.
2. Too many matches.
   • Anchor regex (^...$) where possible.
   • Narrow from generic language scope to a specific prepared query.
3. Wrong files targeted.
   • Confirm --glob pattern and shell quoting.
   • Add --fail-no-files in CI to catch empty globs.
4. --glob used multiple times.
   • --glob is a single-value argument; cannot repeat.
   • Broader glob + --dry-run, or per-file: fd -e <ext> --strip-cwd-prefix -x srgn --glob '{}' --stdin-detection force-unreadable [OPTIONS] [PATTERN]
5. Unclear behavior across multiple language scopes.
   • Default is intersection (left-to-right narrowing).
   • Use -j for OR behavior.
6. Special characters misinterpreted as regex.
   • Use --literal-string when literal matching is intended.

Reference Loading Guide

Load reference files based on request type:

1. references/cli-cookbook.md
   • Load for routine command construction and practical recipes.
2. references/language-scopes.md
   • Load for prepared query selection by language.
3. references/advanced-patterns.md
   • Load for custom queries, capture substitutions, join semantics, and CI failure modes.
4. references/deepwiki-recursive-notes.md
   • Load for complete DeepWiki-derived background and architecture context.

Intent-to-Command Map

Use this map to respond quickly:

1. "Rename imports safely"
   • Use language import scope + anchored regex + --glob ... --dry-run.
2. "Update function calls only"
   • Use language call-site scope (for example --python 'function-calls') + exact name regex.
3. "Only comments/docstrings"
   • Use prepared comment/docstring scopes, add -j only when OR semantics are required.
4. "CI should fail if pattern appears"
   • Use scoped search + --fail-any.
5. "CI should fail if required pattern is missing"
   • Use scoped search + --fail-none.
6. "I need parseable output"
   • Use --stdout-detection force-pipe.
7. "Regex escaping is painful"
   • Use --literal-string and explicit replacement via --.

Execution Checklist

Before returning a final command, verify:

1. Scope is minimal and syntax-aware where possible.
2. Replacement argument is after -- (if replacement is used).
3. Globs are quoted.
4. --dry-run is present for file edits unless user requested direct apply.
5. Join semantics are explicit when multiple language scopes are used (-j vs default intersect).
6. Failure flags align with user intent (--fail-any, --fail-none, --fail-no-files).
7. Output mode is explicit if user needs machine parsing.