feat: add skill evolution foundation (#514)

scripts/lib/skill-evolution/versioning.js

@@ -0,0 +1,237 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+const { appendFile, ensureDir } = require('../utils');
+
+const VERSION_DIRECTORY_NAME = '.versions';
+const EVOLUTION_DIRECTORY_NAME = '.evolution';
+const EVOLUTION_LOG_TYPES = Object.freeze([
+  'observations',
+  'inspections',
+  'amendments',
+]);
+
+function normalizeSkillDir(skillPath) {
+  if (!skillPath || typeof skillPath !== 'string') {
+    throw new Error('skillPath is required');
+  }
+
+  const resolvedPath = path.resolve(skillPath);
+  if (path.basename(resolvedPath) === 'SKILL.md') {
+    return path.dirname(resolvedPath);
+  }
+
+  return resolvedPath;
+}
+
+function getSkillFilePath(skillPath) {
+  return path.join(normalizeSkillDir(skillPath), 'SKILL.md');
+}
+
+function ensureSkillExists(skillPath) {
+  const skillFilePath = getSkillFilePath(skillPath);
+  if (!fs.existsSync(skillFilePath)) {
+    throw new Error(`Skill file not found: ${skillFilePath}`);
+  }
+
+  return skillFilePath;
+}
+
+function getVersionsDir(skillPath) {
+  return path.join(normalizeSkillDir(skillPath), VERSION_DIRECTORY_NAME);
+}
+
+function getEvolutionDir(skillPath) {
+  return path.join(normalizeSkillDir(skillPath), EVOLUTION_DIRECTORY_NAME);
+}
+
+function getEvolutionLogPath(skillPath, logType) {
+  if (!EVOLUTION_LOG_TYPES.includes(logType)) {
+    throw new Error(`Unknown evolution log type: ${logType}`);
+  }
+
+  return path.join(getEvolutionDir(skillPath), `${logType}.jsonl`);
+}
+
+function ensureSkillVersioning(skillPath) {
+  ensureSkillExists(skillPath);
+
+  const versionsDir = getVersionsDir(skillPath);
+  const evolutionDir = getEvolutionDir(skillPath);
+
+  ensureDir(versionsDir);
+  ensureDir(evolutionDir);
+
+  for (const logType of EVOLUTION_LOG_TYPES) {
+    const logPath = getEvolutionLogPath(skillPath, logType);
+    if (!fs.existsSync(logPath)) {
+      fs.writeFileSync(logPath, '', 'utf8');
+    }
+  }
+
+  return {
+    versionsDir,
+    evolutionDir,
+  };
+}
+
+function parseVersionNumber(fileName) {
+  const match = /^v(\d+)\.md$/.exec(fileName);
+  if (!match) {
+    return null;
+  }
+
+  return Number(match[1]);
+}
+
+function listVersions(skillPath) {
+  const versionsDir = getVersionsDir(skillPath);
+  if (!fs.existsSync(versionsDir)) {
+    return [];
+  }
+
+  return fs.readdirSync(versionsDir)
+    .map(fileName => {
+      const version = parseVersionNumber(fileName);
+      if (version === null) {
+        return null;
+      }
+
+      const filePath = path.join(versionsDir, fileName);
+      const stats = fs.statSync(filePath);
+
+      return {
+        version,
+        path: filePath,
+        created_at: stats.mtime.toISOString(),
+      };
+    })
+    .filter(Boolean)
+    .sort((left, right) => left.version - right.version);
+}
+
+function getCurrentVersion(skillPath) {
+  const skillFilePath = getSkillFilePath(skillPath);
+  if (!fs.existsSync(skillFilePath)) {
+    return 0;
+  }
+
+  const versions = listVersions(skillPath);
+  if (versions.length === 0) {
+    return 1;
+  }
+
+  return versions[versions.length - 1].version;
+}
+
+function appendEvolutionRecord(skillPath, logType, record) {
+  ensureSkillVersioning(skillPath);
+  appendFile(getEvolutionLogPath(skillPath, logType), `${JSON.stringify(record)}\n`);
+  return { ...record };
+}
+
+function readJsonl(filePath) {
+  if (!fs.existsSync(filePath)) {
+    return [];
+  }
+
+  return fs.readFileSync(filePath, 'utf8')
+    .split('\n')
+    .map(line => line.trim())
+    .filter(Boolean)
+    .reduce((rows, line) => {
+      try {
+        rows.push(JSON.parse(line));
+      } catch {
+        // Ignore malformed rows so the log remains append-only and resilient.
+      }
+      return rows;
+    }, []);
+}
+
+function getEvolutionLog(skillPath, logType) {
+  return readJsonl(getEvolutionLogPath(skillPath, logType));
+}
+
+function createVersion(skillPath, options = {}) {
+  const skillFilePath = ensureSkillExists(skillPath);
+  ensureSkillVersioning(skillPath);
+
+  const versions = listVersions(skillPath);
+  const nextVersion = versions.length === 0 ? 1 : versions[versions.length - 1].version + 1;
+  const snapshotPath = path.join(getVersionsDir(skillPath), `v${nextVersion}.md`);
+  const skillContent = fs.readFileSync(skillFilePath, 'utf8');
+  const createdAt = options.timestamp || new Date().toISOString();
+
+  fs.writeFileSync(snapshotPath, skillContent, 'utf8');
+  appendEvolutionRecord(skillPath, 'amendments', {
+    event: 'snapshot',
+    version: nextVersion,
+    reason: options.reason || null,
+    author: options.author || null,
+    status: 'applied',
+    created_at: createdAt,
+  });
+
+  return {
+    version: nextVersion,
+    path: snapshotPath,
+    created_at: createdAt,
+  };
+}
+
+function rollbackTo(skillPath, targetVersion, options = {}) {
+  const normalizedTargetVersion = Number(targetVersion);
+  if (!Number.isInteger(normalizedTargetVersion) || normalizedTargetVersion <= 0) {
+    throw new Error(`Invalid target version: ${targetVersion}`);
+  }
+
+  ensureSkillExists(skillPath);
+  ensureSkillVersioning(skillPath);
+
+  const targetPath = path.join(getVersionsDir(skillPath), `v${normalizedTargetVersion}.md`);
+  if (!fs.existsSync(targetPath)) {
+    throw new Error(`Version not found: v${normalizedTargetVersion}`);
+  }
+
+  const currentVersion = getCurrentVersion(skillPath);
+  const targetContent = fs.readFileSync(targetPath, 'utf8');
+  fs.writeFileSync(getSkillFilePath(skillPath), targetContent, 'utf8');
+
+  const createdVersion = createVersion(skillPath, {
+    timestamp: options.timestamp,
+    reason: options.reason || `rollback to v${normalizedTargetVersion}`,
+    author: options.author || null,
+  });
+
+  appendEvolutionRecord(skillPath, 'amendments', {
+    event: 'rollback',
+    version: createdVersion.version,
+    source_version: currentVersion,
+    target_version: normalizedTargetVersion,
+    reason: options.reason || null,
+    author: options.author || null,
+    status: 'applied',
+    created_at: options.timestamp || new Date().toISOString(),
+  });
+
+  return createdVersion;
+}
+
+module.exports = {
+  EVOLUTION_DIRECTORY_NAME,
+  EVOLUTION_LOG_TYPES,
+  VERSION_DIRECTORY_NAME,
+  appendEvolutionRecord,
+  createVersion,
+  ensureSkillVersioning,
+  getCurrentVersion,
+  getEvolutionDir,
+  getEvolutionLog,
+  getEvolutionLogPath,
+  getVersionsDir,
+  listVersions,
+  rollbackTo,
+};