feat(index): add 'extraCacheKeys' option

Author: oscard0m

src/index.ts

@@ -86,7 +86,7 @@ const typescript: PluginImpl<RPT2Options> = (options) =>
 		{
 			check: true,
 			verbosity: VerbosityLevel.Warning,
-			clean: true,
+			clean: !options?.extraCacheKeys && (options?.sourceMapCallback || options?.transformers),
 			cacheRoot: findCacheDir({ name: "rollup-plugin-typescript2" }),
 			include: ["*.ts+(|x)", "**/*.ts+(|x)"],
 			exclude: ["*.d.ts", "**/*.d.ts"],
@@ -99,6 +99,7 @@ const typescript: PluginImpl<RPT2Options> = (options) =>
 			tsconfigDefaults: {},
 			objectHashIgnoreUnknownHack: false,
 			cwd: process.cwd(),
+			extraCacheKeys: []
 		}, options as IOptions);
 
 	if (!pluginOptions.typescript) {

src/ioptions.ts

@@ -30,4 +30,5 @@ export interface IOptions
 	tsconfigDefaults: any;
 	sourceMapCallback: (id: string, map: string) => void;
 	objectHashIgnoreUnknownHack: boolean;
+	extraCacheKeys: string[]
 }