commit-message-generator

name	commit-message-generator
description	Generates Conventional Commits-style commit messages from git diffs or change descriptions
version	1.0.0
author	go-on-team
tags	["git","commit","conventional-commits","version-control","workflow"]
min_go_on_version	1.0.0

Commit Message Generator Skill

Analyzes code changes (from git diff or natural-language description) and generates well-structured commit messages following the Conventional Commits specification. Includes scope detection, breaking change identification, and body generation.

How It Works

1. Analyze — Examines the diff or change description to categorize the type of change (feature, fix, refactor, docs, test, chore, etc.)
2. Scope — Detects the affected module/component from file paths (e.g. src/api/ → api, src/db/ → db)
3. Compose — Writes a concise subject line (<72 chars), optional body with context, and footer with breaking change notes or issue references
4. Validate — Checks the output conforms to the Conventional Commits specification and suggests improvements

Input Schema

Parameter	Type	Description
diff	string	Git diff output (git diff) or path-based change description
description	string	Optional: natural-language description of the change
style	string	Commit style: conventional, angular, simple (default: conventional)
include_body	boolean	Optional: generate detailed body (default: true)
breaking_change	string	Optional: description if the change is breaking

Example

{
  "diff": "diff --git a/src/cache/lru.rs b/src/cache/lru.rs\n@@ -42,7 +42,7 @@ impl LruCache {\n         self.order.pop_front()\n     }\n \n-    pub fn insert(&mut self, key: K, value: V) {\n+    pub fn insert(&mut self, key: K, value: V) -> Option<V> {\n         if self.order.len() >= self.capacity {\n             self.evict();\n         }\n-        self.order.push_back((key, value));\n+        let replaced = self.map.insert(key.clone(), value);\n+        self.order.push_back((key, value.clone()));\n+        replaced\n     }\n }\n",
  "description": "Make LruCache.insert return the previous value if the key already existed",
  "style": "conventional",
  "include_body": true
}

Example output:

feat(cache): make insert() return the replaced value

Changed LruCache::insert() to return Option<V> instead of unit,
providing callers with the previously stored value when a key
is overwritten. This enables callers to track evictions and
handle value replacement without an additional lookup.

Closes: #142