Extending rollup config to treat any file from a peer dep as an external

Author: weaverryan

rollup.config.js

@@ -4,6 +4,39 @@ import glob from 'glob';
 import path from 'path';
 import pkgUp from 'pkg-up';
 
+/**
+ * Guarantees that any files imported from a peer dependency are treated as an external.
+ *
+ * For example, if we import `chart.js/auto`, that would not normally
+ * match the "chart.js" we pass to the "externals" config. This plugin
+ * catches that case and adds it as an external.
+ *
+ * Inspired by https://github.com/oat-sa/rollup-plugin-wildcard-external
+ */
+const wildcardExternalsPlugin = (peerDependencies) => ({
+    name: 'wildcard-externals',
+    resolveId(source, importer) {
+        if (importer) {
+            let matchesExternal = false;
+            peerDependencies.forEach((peerDependency) => {
+                if (source.includes(`/${peerDependency}/`)) {
+                    matchesExternal = true;
+                }
+            });
+
+            if (matchesExternal) {
+                return {
+                    id: source,
+                    external: true,
+                    moduleSideEffects: true
+                };
+            }
+        }
+
+        return null; // other ids should be handled as usually
+    }
+});
+
 const files = glob.sync("src/**/assets/src/*controller.ts");
 const packages = files.map((file) => {
     const absolutePath = path.join(__dirname, file);
@@ -23,6 +56,7 @@ const packages = files.map((file) => {
         plugins: [
             resolve(),
             typescript(),
+            wildcardExternalsPlugin(peerDependencies)
         ],
     };
 });