Initial commit: omp-ast DSH plugin (oh-my-pi port) with docs and tests

lib/sg.js

@@ -0,0 +1,60 @@
+// ast-grep CLI wrapper.
+import { execFile } from 'node:child_process'
+import fs from 'node:fs'
+import path from 'node:path'
+
+let sgPath
+export function findAstGrep(extra = []) {
+  if (sgPath !== undefined) return sgPath
+  const dirs = [...extra, ...(process.env.PATH || '').split(path.delimiter), path.join(process.env.HOME || '', '.local/bin'), '/usr/local/bin']
+  sgPath = null
+  for (const d of dirs) {
+    if (!d) continue
+    const p = path.join(d, 'ast-grep') // `sg` collides with util-linux's setgroups on many distros
+    try { fs.accessSync(p, fs.constants.X_OK); sgPath = p; break } catch {}
+  }
+  return sgPath
+}
+
+export function run(bin, args, { cwd, signal, timeoutMs = 120_000, maxBuffer = 64 * 1024 * 1024 } = {}) {
+  return new Promise((resolve) => {
+    execFile(bin, args, { cwd, signal, timeout: timeoutMs, maxBuffer, encoding: 'utf8' }, (error, stdout, stderr) => {
+      resolve({ code: error ? (typeof error.code === 'number' ? error.code : 1) : 0, stdout: stdout ?? '', stderr: stderr ?? '', error })
+    })
+  })
+}
+
+/**
+ * Run a pattern (optionally with rewrite) and return parsed matches.
+ * @returns {{matches: object[], warnings: string[]}}
+ */
+export async function search({ bin, pattern, rewrite, lang, paths, cwd, globs, strictness, selector, signal }) {
+  const args = ['run', '--pattern', pattern, '--json=compact', '--color=never']
+  if (rewrite !== undefined) args.push('--rewrite', rewrite)
+  if (lang) args.push('--lang', lang)
+  if (strictness) args.push('--strictness', strictness)
+  if (selector) args.push('--selector', selector)
+  for (const g of globs ?? []) args.push('--globs', g)
+  args.push('--', ...(paths?.length ? paths : ['.']))
+  const r = await run(bin, args, { cwd, signal })
+  const warnings = r.stderr.split('\n').map((l) => l.trim()).filter((l) => l && !/^See also|^Help: .*playground/i.test(l))
+  if (r.code !== 0 && !r.stdout.trim().startsWith('[')) {
+    throw new Error(`ast-grep failed: ${warnings.join(' ') || r.error?.message || `exit ${r.code}`}`)
+  }
+  let matches = []
+  try { matches = JSON.parse(r.stdout || '[]') } catch (e) { throw new Error(`ast-grep returned malformed JSON: ${e.message}`) }
+  return { matches, warnings }
+}
+
+/** Apply replacements (byte offsets) to file contents; returns new text. */
+export function applyReplacements(buf, reps) {
+  const sorted = [...reps].sort((a, b) => b.start - a.start)
+  let out = buf
+  let lastStart = Infinity
+  for (const r of sorted) {
+    if (r.end > lastStart) continue // overlapping: keep the outermost-first earlier one
+    out = Buffer.concat([out.subarray(0, r.start), Buffer.from(r.text, 'utf8'), out.subarray(r.end)])
+    lastStart = r.start
+  }
+  return out
+}