Update packages, configs + Node.js 20

.browserslistrc

@@ -0,0 +1,12 @@
+# This list builds on the GOV.UK service manual's browser testing recommendations
+# https://www.gov.uk/service-manual/technology/designing-for-different-browsers-and-devices
+
+> 0.1% in GB and not dead
+last 6 Chrome versions
+last 6 Firefox versions
+last 6 Edge versions
+last 2 Samsung versions
+Firefox ESR
+Safari >= 11
+iOS >= 11
+ie 11

.husky/pre-commit

@@ -0,0 +1,4 @@
+#!/usr/bin/env sh
+. "$(dirname -- "$0")/_/husky.sh"
+
+npm run build && node scripts/check-staged.mjs

.nvmrc

@@ -1 +1 @@
-lts/fermium
+lts/iron

CONTRIBUTING.md

@@ -94,7 +94,7 @@ You should do this and commit it before you attempt to `git push`, otherwise the
 
 ## Prepush checks
 
-When you push to a branch, git will run a `npm run prepush` [script](scripts/check-staged.js) that will compile the build on your behalf to the `dist/` folder. If it then finds unstaged files in `dist/`, it will fail your push.
+When you push to a branch, git will run a `npm run prepush` [script](scripts/check-staged.mjs) that will compile the build on your behalf to the `dist/` folder. If it then finds unstaged files in `dist/`, it will fail your push.
 
 The solution is to commit the files, preferably as part of a separate commit:
 

babel.config.js

@@ -0,0 +1,29 @@
+/**
+ * Babel config
+ *
+ * @type {import('@babel/core').ConfigFunction}
+ */
+module.exports = {
+  presets: [
+    [
+      '@babel/preset-env',
+      {
+        bugfixes: true,
+        corejs: '3.33',
+        loose: true,
+        shippedProposals: true,
+        useBuiltIns: 'usage'
+      }
+    ]
+  ],
+
+  plugins: [
+    ['@babel/plugin-transform-react-jsx', { pragma: 'h' }]
+  ],
+
+  env: {
+    test: {
+      plugins: ['istanbul']
+    }
+  }
+}