feat: allow passing generatorOpts down to Babel (#323)

* feat: allow passing generatorOpts down to Babel

* fix: add babel generator options type

README.md

@@ -42,6 +42,7 @@ Creates the vite plugin from a set of optional plugin options.
 - `opts.checkProd {boolean}` - Optional boolean to enforce the plugin to skip instrumentation for production environments. Looks at Vite's **isProduction** key from the `ResolvedConfig`.
 - `opts.forceBuildInstrument {boolean}` - Optional boolean to enforce the plugin to add instrumentation in build mode. Defaults to false.
 - `opts.nycrcPath {string}` - Path to specific nyc config to use instead of automatically searching for a nycconfig. This parameter is just passed down to `@istanbuljs/load-nyc-config`.
+- `opts.generatorOpts {GeneratorOptions}` - A set of generator options that are passed down to the Babel transformer. See [here](https://babeljs.io/docs/babel-generator#options) for reference. Defaults to empty object.
 
 Notes
 --------------------------

package.json

@@ -56,6 +56,7 @@
     "@ianvs/prettier-plugin-sort-imports": "4.4.1",
     "@semantic-release/changelog": "6.0.3",
     "@semantic-release/git": "10.0.1",
+    "@types/babel__generator": "7.6.8",
     "@types/node": "22.10.5",
     "@types/ws": "8.5.13",
     "husky": "9.1.7",

src/index.ts

@@ -1,4 +1,5 @@
 import { loadNycConfig } from '@istanbuljs/load-nyc-config';
+import type { GeneratorOptions } from 'babel__generator';
 import { createInstrumenter } from 'istanbul-lib-instrument';
 import picocolors from 'picocolors';
 import type { ExistingRawSourceMap } from 'rollup';
@@ -25,6 +26,7 @@ export interface IstanbulPluginOptions {
   forceBuildInstrument?: boolean;
   cwd?: string;
   nycrcPath?: string;
+  generatorOpts?: GeneratorOptions;
 }
 
 // Custom extensions to include .vue files
@@ -117,6 +119,7 @@ export default function istanbulPlugin(
     autoWrap: true,
     esModules: true,
     compact: false,
+    generatorOpts: { ...opts?.generatorOpts },
   });
 
   // Lazy check the active status of the plugin

src/types.d.ts

@@ -1,5 +1,6 @@
 declare module 'istanbul-lib-instrument' {
   import { ExistingRawSourceMap } from 'rollup';
+  import { GeneratorOptions } from 'babel__generator';
 
   interface Instrumenter {
     instrumentSync(
@@ -24,6 +25,7 @@ declare module 'istanbul-lib-instrument' {
     parserPlugins?: any[];
     coverageGlobalScope?: string;
     coverageGlobalScopeFunc?: boolean;
+    generatorOpts?: GeneratorOptions;
   }): Instrumenter;
 }