fix: timed plugin context (#4357)

* fix: timed plugin context

* add test

src/utils/timers.ts

@@ -1,4 +1,4 @@
-import { InputOptions, Plugin, SerializedTimings } from '../rollup/types';
+import type { InputOptions, Plugin, SerializedTimings } from '../rollup/types';
 import performance from './performance';
 import process from './process';
 
@@ -77,18 +77,19 @@ export let timeEnd: (label: string, level?: number) => void = NOOP;
 const TIMED_PLUGIN_HOOKS = ['load', 'resolveDynamicImport', 'resolveId', 'transform'] as const;
 
 function getPluginWithTimers(plugin: any, index: number): Plugin {
-	const timedPlugin: Pick<Plugin, typeof TIMED_PLUGIN_HOOKS[number]> = {};
-
 	for (const hook of TIMED_PLUGIN_HOOKS) {
 		if (hook in plugin) {
 			let timerLabel = `plugin ${index}`;
 			if (plugin.name) {
 				timerLabel += ` (${plugin.name})`;
 			}
 			timerLabel += ` - ${hook}`;
-			timedPlugin[hook] = function (...args: unknown[]) {
+
+			const func = plugin[hook];
+
+			plugin[hook] = function (...args: readonly unknown[]) {
 				timeStart(timerLabel, 4);
-				const result = plugin[hook](...args);
+				const result = func.apply(this, args);
 				timeEnd(timerLabel, 4);
 				if (result && typeof result.then === 'function') {
 					timeStart(`${timerLabel} (async)`, 4);
@@ -101,10 +102,7 @@ function getPluginWithTimers(plugin: any, index: number): Plugin {
 			};
 		}
 	}
-	return {
-		...plugin,
-		...timedPlugin
-	};
+	return plugin;
 }
 
 export function initialiseTimers(inputOptions: InputOptions): void {

test/function/samples/adds-plugin-context-to-plugins/_config.js

@@ -0,0 +1,27 @@
+const assert = require('assert');
+
+module.exports = {
+	description: 'Adds plugin context to plugins with perf=true',
+	options: {
+		perf: true,
+		plugins: [
+			{
+				load() {
+					assert.ok(typeof this.parse === 'function');
+				},
+
+				resolveDynamicImport() {
+					assert.ok(typeof this.parse === 'function');
+				},
+
+				resolveId() {
+					assert.ok(typeof this.parse === 'function');
+				},
+
+				transform() {
+					assert.ok(typeof this.parse === 'function');
+				}
+			}
+		]
+	}
+};

test/function/samples/adds-plugin-context-to-plugins/foo.js

@@ -0,0 +1 @@
+export default 'foo';

test/function/samples/adds-plugin-context-to-plugins/main.js

@@ -0,0 +1 @@
+import('./foo');