fix: adjust webpack config for legacy TypeScript versions

Author: pedromdev

lib/webpackConfigFactory.js

@@ -8,6 +8,9 @@ const root = path.resolve(__dirname, '..');
 
 module.exports = function webpackConfigFactory(libname, dirname, config = {}) {
   return function (env, argv) {
+    const tsVersion = ts.version;
+    const isLegacyTs = parseInt(tsVersion.split('.')[0]) < 5;
+
     return defaultsDeep(config, {
       entry: path.resolve(dirname, 'src/index.ts'),
       devtool: argv.mode !== 'production' ? 'inline-source-map' : false,
@@ -34,15 +37,22 @@ module.exports = function webpackConfigFactory(libname, dirname, config = {}) {
             test: /\.ts?$/,
             loader: 'ts-loader',
             exclude: /node_modules/,
+            options: {
+              compilerOptions: {
+                declaration: true,
+                declarationDir: isLegacyTs ? path.resolve(dirname, 'src') : undefined
+              }
+            }
           }
         ]
       },
       plugins: [
         new DtsBundleWebpack({
           name: libname,
-          main: 'src/index.d.ts',
+          main: isLegacyTs ? 'src/index.d.ts' : 'src/index.d.ts',
           out: path.join(dirname, 'index.d.ts'),
-          removeSource: true
+          removeSource: true,
+          outputAsModuleFolder: true
         }),
       ]
     });