feat: add prerelease checks script

package.json

@@ -60,7 +60,7 @@
     "rollup-plugin-visualizer": "^5.9.2"
   },
   "scripts": {
-    "release": "yarn run test && yarn run build",
+    "release": "node ./prerelease.js && yarn run test && yarn run build",
     "build": "rm -rf ./dist/ && yarn run build:bundle && yarn run build:minify",
     "build:bundle": "rollup -c",
     "build:minify": "minify ./dist/doip.core.js > ./dist/doip.core.min.js && minify ./dist/doip.fetchers.js > ./dist/doip.fetchers.min.js && minify ./dist/doip.fetchers.minimal.js > ./dist/doip.fetchers.minimal.min.js",

prerelease.js

@@ -0,0 +1,33 @@
+/*
+Copyright 2023 Yarmo Mackenbach
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+import * as C from './src/constants.js'
+import { readFile } from 'fs/promises'
+
+const main = async () => {
+  const pkg = JSON.parse(
+    await readFile(
+      new URL('./package.json', import.meta.url)
+    )
+  )
+
+  // Assert that the constant version equals the package version
+  if (C.version !== pkg.version) {
+    console.log(`!!! Mismatch between constants.js version (${C.version}) and package.json version (${pkg.version})`)
+    process.exit(1)
+  }
+}
+
+main()