feat: run test script for all pkgs with changed files

package.json

@@ -70,6 +70,7 @@
     "testRegex": "\\.spec\\.js$"
   },
   "lint-staged": {
+    "*": "scripts/run-changed-pkgs.js test",
     "*.{{,c,m}j,t}s{,x}": [
       "prettier --write",
       "eslint --ignore-pattern '!*'",

scripts/run-changed-pkgs.js

@@ -0,0 +1,28 @@
+#!/usr/bin/env node
+
+'use strict'
+
+const { join, relative, sep } = require('path')
+
+const [, , script, ...files] = process.argv
+
+const pkgs = new Set()
+const root = join(__dirname, '..')
+for (const file of files) {
+  const parts = relative(root, file).split(sep)
+  if ((parts.length > 2 && parts[0] === 'packages') || parts[0][0] === '@') {
+    pkgs.add(parts.slice(0, 2).join(sep))
+  }
+}
+
+if (pkgs.size !== 0) {
+  const args = ['run', '--if-present', script]
+  for (const pkg of pkgs) {
+    args.push('-w', pkg)
+  }
+
+  const { status } = require('child_process').spawnSync('npm', args, { stdio: 'inherit' })
+  if (status !== 0) {
+    process.exit(status)
+  }
+}