- if output.file not exist use output.dir

src/index.ts

@@ -283,7 +283,7 @@ const typescript: PluginImpl<Partial<IOptions>> = (options) =>
 			generateRound++;
 		},
 
-		_onwrite({ file }: OutputOptions): void
+		_onwrite({ file, dir }: OutputOptions): void
 		{
 			if (parsedConfig.options.declaration)
 			{
@@ -300,6 +300,7 @@ const typescript: PluginImpl<Partial<IOptions>> = (options) =>
 				});
 
 				const bundleFile = file;
+				const outputDir = dir;
 
 				const writeDeclaration = (key: string, extension: string, entry?: tsTypes.OutputFile) =>
 				{
@@ -313,12 +314,12 @@ const typescript: PluginImpl<Partial<IOptions>> = (options) =>
 					let writeToPath: string;
 					// If for some reason no 'dest' property exists or if 'useTsconfigDeclarationDir' is given in the plugin options,
 					// use the path provided by Typescript's LanguageService.
-					if (!bundleFile || pluginOptions.useTsconfigDeclarationDir)
+					if ((!bundleFile && !outputDir) || pluginOptions.useTsconfigDeclarationDir)
 						writeToPath = fileName;
 					else
 					{
 						// Otherwise, take the directory name from the path and make sure it is absolute.
-						const destDirname = dirname(bundleFile);
+						const destDirname = bundleFile ? dirname(bundleFile) : <string>outputDir;
 						const destDirectory = isAbsolute(destDirname) ? destDirname : join(process.cwd(), destDirname);
 						writeToPath = join(destDirectory, relative(process.cwd(), fileName));
 					}