feat: support inline sourceMaps for easier debugging (#46)

Co-authored-by: Pooya Parsa <pyapar@gmail.com>

README.md

@@ -87,6 +87,14 @@ Using esm resolution algorithm to support `import` condition.
 
 Transform function. See [src/babel](./src/babel.ts) for more details
 
+### `sourceMaps`
+
+- Type: Boolean
+- Default `false`
+- Environment Vriable: `JITI_SOURCE_MAPS`
+
+Add inline source map to transformed source for better debugging.
+
 ## Development
 
 - Clone Repo

src/jiti.ts

@@ -18,13 +18,15 @@ const _EnvDebug = destr(process.env.JITI_DEBUG)
 const _EnvCache = destr(process.env.JITI_CACHE)
 const _EnvESMReolve = destr(process.env.JITI_ESM_RESOLVE)
 const _EnvRequireCache = destr(process.env.JITI_REQUIRE_CACHE)
+const _EnvSourceMaps = destr(process.env.JITI_SOURCE_MAPS)
 
 const isWindows = platform() === 'win32'
 
 const defaults: JITIOptions = {
   debug: _EnvDebug,
   cache: _EnvCache !== undefined ? !!_EnvCache : true,
   requireCache: _EnvRequireCache !== undefined ? !!_EnvRequireCache : true,
+  sourceMaps: _EnvSourceMaps !== undefined ? !!_EnvSourceMaps : false,
   interopDefault: false,
   esmResolve: _EnvESMReolve || false,
   cacheVersion: '6',
@@ -162,6 +164,15 @@ export default function createJITI (_filename: string, opts: JITIOptions = {}, p
       const res = opts.transform!({
         legacy: opts.legacy,
         ...opts.transformOptions,
+        babel: {
+          ...(opts.sourceMaps
+            ? {
+                sourceFileName: topts.filename,
+                sourceMaps: 'inline'
+              }
+            : {}),
+          ...opts.transformOptions?.babel
+        },
         ...topts
       })
       if (res.error && opts.debug) {

src/types.ts

@@ -17,6 +17,7 @@ export type JITIOptions = {
   transform?: (opts: TransformOptions) => TRANSFORM_RESULT,
   debug?: boolean,
   cache?: boolean | string
+  sourceMaps?: boolean
   requireCache?: boolean
   v8cache?: boolean
   interopDefault?: boolean