From 31d01acb6e2ea7b97460b0aea644b9f228d2b0a2 Mon Sep 17 00:00:00 2001
From: Colin Rotherham <work@colinr.com>
Date: Mon, 19 Jun 2023 09:34:15 +0100
Subject: [PATCH] Make Babel a dependency unless bundled

---
 package-lock.json                             | 39 ++++++++++++++++++-
 packages/govuk-frontend/package.json          |  4 ++
 packages/govuk-frontend/rollup.esm.config.mjs |  8 +++-
 3 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 6b96031a9a..0b63ad844a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1585,6 +1585,26 @@
         "@babel/core": "^7.0.0-0"
       }
     },
+    "node_modules/@babel/plugin-transform-runtime": {
+      "version": "7.22.5",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-transform-runtime/-/plugin-transform-runtime-7.22.5.tgz",
+      "integrity": "sha512-bg4Wxd1FWeFx3daHFTWk1pkSWK/AyQuiyAoeZAOkAOUBjnZPH6KT7eMxouV47tQ6hl6ax2zyAWBdWZXbrvXlaw==",
+      "dev": true,
+      "dependencies": {
+        "@babel/helper-module-imports": "^7.22.5",
+        "@babel/helper-plugin-utils": "^7.22.5",
+        "babel-plugin-polyfill-corejs2": "^0.4.3",
+        "babel-plugin-polyfill-corejs3": "^0.8.1",
+        "babel-plugin-polyfill-regenerator": "^0.5.0",
+        "semver": "^6.3.0"
+      },
+      "engines": {
+        "node": ">=6.9.0"
+      },
+      "peerDependencies": {
+        "@babel/core": "^7.0.0-0"
+      }
+    },
     "node_modules/@babel/plugin-transform-shorthand-properties": {
       "version": "7.22.5",
       "resolved": "https://registry.npmjs.org/@babel/plugin-transform-shorthand-properties/-/plugin-transform-shorthand-properties-7.22.5.tgz",
@@ -22032,8 +22052,7 @@
     "node_modules/regenerator-runtime": {
       "version": "0.13.11",
       "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.11.tgz",
-      "integrity": "sha512-kY1AZVr2Ra+t+piVaJ4gxaFaReZVH40AKNo7UCX6W+dEwBo/2oZJzqfuN1qLq1oL45o56cPaTXELwrTh8Fpggg==",
-      "dev": true
+      "integrity": "sha512-kY1AZVr2Ra+t+piVaJ4gxaFaReZVH40AKNo7UCX6W+dEwBo/2oZJzqfuN1qLq1oL45o56cPaTXELwrTh8Fpggg=="
     },
     "node_modules/regenerator-transform": {
       "version": "0.15.1",
@@ -27590,6 +27609,7 @@
       "license": "MIT",
       "devDependencies": {
         "@babel/core": "^7.22.5",
+        "@babel/plugin-transform-runtime": "^7.22.5",
         "@babel/preset-env": "^7.22.5",
         "@rollup/plugin-babel": "^6.0.3",
         "@rollup/plugin-replace": "^5.0.2",
@@ -27619,6 +27639,9 @@
         "govuk-frontend-helpers": "*",
         "govuk-frontend-lib": "*",
         "govuk-frontend-tasks": "*"
+      },
+      "peerDependencies": {
+        "@babel/runtime": "^7.22.5"
       }
     },
     "packages/govuk-frontend-review": {
@@ -27665,6 +27688,18 @@
         "npm": "^8.1.0 || ^9.1.0"
       }
     },
+    "packages/govuk-frontend/node_modules/@babel/runtime": {
+      "version": "7.22.5",
+      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.22.5.tgz",
+      "integrity": "sha512-ecjvYlnAaZ/KVneE/OdKYBYfgXV3Ptu6zQWmgEF7vwKhQnvVS6bjMD2XYgj+SNvQ1GfK/pjgokfPkC/2CO8CuA==",
+      "peer": true,
+      "dependencies": {
+        "regenerator-runtime": "^0.13.11"
+      },
+      "engines": {
+        "node": ">=6.9.0"
+      }
+    },
     "shared/config": {
       "name": "govuk-frontend-config",
       "license": "MIT",
diff --git a/packages/govuk-frontend/package.json b/packages/govuk-frontend/package.json
index f02692d3c8..7b4542eb58 100644
--- a/packages/govuk-frontend/package.json
+++ b/packages/govuk-frontend/package.json
@@ -53,6 +53,7 @@
   },
   "devDependencies": {
     "@babel/core": "^7.22.5",
+    "@babel/plugin-transform-runtime": "^7.22.5",
     "@babel/preset-env": "^7.22.5",
     "@rollup/plugin-babel": "^6.0.3",
     "@rollup/plugin-replace": "^5.0.2",
@@ -79,5 +80,8 @@
     "govuk-frontend-helpers": "*",
     "govuk-frontend-lib": "*",
     "govuk-frontend-tasks": "*"
+  },
+  "peerDependencies": {
+    "@babel/runtime": "^7.22.5"
   }
 }
diff --git a/packages/govuk-frontend/rollup.esm.config.mjs b/packages/govuk-frontend/rollup.esm.config.mjs
index 565f51ba3c..343a964ca9 100644
--- a/packages/govuk-frontend/rollup.esm.config.mjs
+++ b/packages/govuk-frontend/rollup.esm.config.mjs
@@ -33,7 +33,11 @@ export default defineConfig(({ i: input }) => ({
       development: pkg.version
     }),
     babel({
-      babelHelpers: 'bundled'
+      babelHelpers: 'runtime',
+      plugins: ['@babel/plugin-transform-runtime']
     })
-  ]
+  ],
+
+  // Keep Babel as a dependency
+  external: (id) => id.includes('@babel/runtime')
 }))