fix: handle extension-less files (#12)

package.json

@@ -31,7 +31,7 @@
 		"test": "node --loader @esbuild-kit/esm-loader tests"
 	},
 	"dependencies": {
-		"@esbuild-kit/core-utils": "^1.1.1",
+		"@esbuild-kit/core-utils": "^1.1.2",
 		"es-module-lexer": "^0.10.5",
 		"get-tsconfig": "^3.0.1"
 	},

src/loaders-deprecated.ts

@@ -37,7 +37,7 @@ const _getFormat: getFormat = async function (
 		return { format: 'module' };
 	}
 
-	if (tsExtensionsPattern.test(url)) {
+	if (url.startsWith('file:')) {
 		const format = getFormatFromExtension(url) ?? await getPackageType(url);
 		return { format };
 	}
@@ -89,7 +89,7 @@ const _transformSource: transformSource = async function (
 	}
 
 	const result = await defaultTransformSource(source, context, defaultTransformSource);
-	const dynamicImportTransformed = transformDynamicImport({ code: result.source });
+	const dynamicImportTransformed = transformDynamicImport({ code: result.source.toString() });
 	if (dynamicImportTransformed) {
 		result.source = dynamicImportTransformed.code;
 

src/loaders.ts

@@ -108,15 +108,20 @@ export const resolve: resolve = async function (
 		};
 	}
 
-	if (tsExtensionsPattern.test(resolved.url)) {
-		const format = getFormatFromExtension(resolved.url) ?? await getPackageType(resolved.url);
-		return {
-			...resolved,
-			format,
-		};
+	let { format } = resolved;
+
+	if (resolved.url.startsWith('file:')) {
+		format = getFormatFromExtension(resolved.url) ?? format;
+
+		if (!format) {
+			format = await getPackageType(resolved.url);
+		}
 	}
 
-	return resolved;
+	return {
+		...resolved,
+		format,
+	};
 };
 
 type load = (

src/utils.ts

@@ -6,11 +6,11 @@ export const tsExtensionsPattern = /\.([cm]?ts|[tj]sx)$/;
 export const getFormatFromExtension = (filePath: string): ModuleFormat | undefined => {
 	const extension = path.extname(filePath);
 
-	if (extension === '.mts') {
+	if (extension === '.mjs' || extension === '.mts') {
 		return 'module';
 	}
 
-	if (extension === '.cts') {
+	if (extension === '.cjs' || extension === '.cts') {
 		return 'commonjs';
 	}
 };