Add documentation and ES build

docs/javascript-api/index.md

@@ -280,7 +280,7 @@ const watchOptions = {
 
 See above for details on `inputOptions` and `outputOptions`, or consult the [big list of options](../configuration-options/index.md) for info on `chokidar`, `include` and `exclude`.
 
-### Programmatically loading a config file
+## Programmatically loading a config file
 
 In order to aid in generating such a config, rollup exposes the helper it uses to load config files in its command line interface via a separate entry-point. This helper receives a resolved `fileName` and optionally an object containing command line parameters:
 
@@ -315,3 +315,24 @@ loadConfigFile(path.resolve(__dirname, 'rollup.config.js'), {
 	rollup.watch(options);
 });
 ```
+
+## Applying advanced log filters
+
+While the command line interface provides a powerful way to filter logs via the [`--filterLogs`](../command-line-interface/#filterlogs-filter) flag, this functionality is not directly available when using the JavaScript API. However, Rollup exposes a helper `getLogFilter` to generate filters using the same syntax as the CLI. This is useful when specifying a custom `onLog` handler and for third party systems that want to provide a similar filtering experience as Rollup CLI. This function accepts an array of strings. Note that it does not split up comma-separated lists of filters like the CLI does.
+
+```js
+// rollup.config.mjs
+import { getLogFilter } from 'rollup/getLogFilter';
+
+const logFilter = getLogFilter(['code:FOO', 'code:BAR']);
+
+export default {
+	input: 'main.js',
+	output: { format: 'es' },
+	onLog(level, log, handler) {
+		if (logFilter(log)) {
+			handler(level, log);
+		}
+	}
+};
+```

package.json

@@ -170,7 +170,7 @@
     "./getLogFilter": {
       "types": "./dist/getLogFilter.d.ts",
       "require": "./dist/getLogFilter.js",
-      "default": "./dist/getLogFilter.js"
+      "import": "./dist/es/getLogFilter.js"
     },
     "./dist/*": "./dist/*"
   }

rollup.config.ts

@@ -95,7 +95,10 @@ export default async function (
 
 	const esmBuild: RollupOptions = {
 		...commonJSBuild,
-		input: { 'rollup.js': 'src/node-entry.ts' },
+		input: {
+			'getLogFilter.js': 'src/utils/getLogFilter.ts',
+			'rollup.js': 'src/node-entry.ts'
+		},
 		output: {
 			...commonJSBuild.output,
 			dir: 'dist/es',