feat(ruleset-bundler): plugins should be easy to override

packages/ruleset-bundler/src/index.ts

@@ -1,6 +1,7 @@
 import { rollup, Plugin } from 'rollup';
 import { isURL } from '@stoplight/path';
 import { isPackageImport } from './utils/isPackageImport';
+import { dedupeRollupPlugins } from './utils/dedupeRollupPlugins';
 
 export type BundleOptions = {
   plugins: Plugin[];
@@ -17,7 +18,7 @@ export async function bundleRuleset(
 ): Promise<string> {
   const bundle = await rollup({
     input,
-    plugins,
+    plugins: dedupeRollupPlugins(plugins),
     treeshake,
     watch: false,
     perf: false,

packages/ruleset-bundler/src/utils/__tests__/dedupeRollupPlugins.spec.ts

@@ -0,0 +1,51 @@
+import type { Plugin } from 'rollup';
+
+import { dedupeRollupPlugins } from '../dedupeRollupPlugins';
+
+describe('dedupeRollupPlugins util', () => {
+  it('should keep plugins with different names', () => {
+    const plugins: Plugin[] = [
+      {
+        name: 'plugin 1',
+      },
+      {
+        name: 'plugin 2',
+      },
+      {
+        name: 'plugin 3',
+      },
+    ];
+
+    expect(dedupeRollupPlugins([...plugins])).toStrictEqual(plugins);
+  });
+
+  it('given the same plugin, should replace the first declaration', () => {
+    const plugins: Plugin[] = [
+      {
+        name: 'plugin 1',
+        cacheKey: 'key 1',
+      },
+      {
+        name: 'plugin 2',
+      },
+      {
+        name: 'plugin 1',
+        cacheKey: 'key 2',
+      },
+      {
+        name: 'plugin 1',
+        cacheKey: 'key 3',
+      },
+    ];
+
+    expect(dedupeRollupPlugins([...plugins])).toStrictEqual([
+      {
+        name: 'plugin 1',
+        cacheKey: 'key 3',
+      },
+      {
+        name: 'plugin 2',
+      },
+    ]);
+  });
+});

packages/ruleset-bundler/src/utils/dedupeRollupPlugins.ts

@@ -0,0 +1,12 @@
+// this function makes sure we can only have one plugin with the same name
+// the last plugin definition has a precedence
+import type { Plugin } from 'rollup';
+
+export function dedupeRollupPlugins(plugins: Plugin[]): Plugin[] {
+  const map = new Map<string, Plugin>();
+  for (const plugin of plugins) {
+    map.set(plugin.name, plugin);
+  }
+
+  return Array.from(map.values());
+}