Adding upstream version 5.2.3+dfsg.

Signed-off-by: Daniel Baumann <daniel@debian.org>

build/rollup.config.js

@@ -0,0 +1,57 @@
+'use strict'
+
+const path = require('node:path')
+const { babel } = require('@rollup/plugin-babel')
+const { nodeResolve } = require('@rollup/plugin-node-resolve')
+const replace = require('@rollup/plugin-replace')
+const banner = require('./banner.js')
+
+const BUNDLE = process.env.BUNDLE === 'true'
+const ESM = process.env.ESM === 'true'
+
+let fileDestination = `bootstrap${ESM ? '.esm' : ''}`
+const external = ['@popperjs/core']
+const plugins = [
+  babel({
+    // Only transpile our source code
+    exclude: 'node_modules/**',
+    // Include the helpers in the bundle, at most one copy of each
+    babelHelpers: 'bundled'
+  })
+]
+const globals = {
+  '@popperjs/core': 'Popper'
+}
+
+if (BUNDLE) {
+  fileDestination += '.bundle'
+  // Remove last entry in external array to bundle Popper
+  external.pop()
+  delete globals['@popperjs/core']
+  plugins.push(
+    replace({
+      'process.env.NODE_ENV': '"production"',
+      preventAssignment: true
+    }),
+    nodeResolve()
+  )
+}
+
+const rollupConfig = {
+  input: path.resolve(__dirname, `../js/index.${ESM ? 'esm' : 'umd'}.js`),
+  output: {
+    banner,
+    file: path.resolve(__dirname, `../dist/js/${fileDestination}.js`),
+    format: ESM ? 'esm' : 'umd',
+    globals,
+    generatedCode: 'es2015'
+  },
+  external,
+  plugins
+}
+
+if (!ESM) {
+  rollupConfig.output.name = 'bootstrap'
+}
+
+module.exports = rollupConfig