Clean up tsc process on ^C.

Author: chriskrycho

lib/serve-ts.js

@@ -59,7 +59,7 @@ module.exports = Serve.extend({
     // TODO: typescript might be installed globally?
     // argument sequence here is meaningful; don't apply prettier.
     // prettier-ignore
-    const tsc = child_process.fork(
+    this.tsc = child_process.fork(
       'node_modules/typescript/bin/tsc',
       [
         '--watch',
@@ -80,6 +80,12 @@ module.exports = Serve.extend({
   },
 
   onInterrupt() {
-    if (fs.existsSync(OUT_DIR)) fs.rmdirSync(OUT_DIR);
+    if (this.tsc) {
+      this.tsc.kill();
+    }
+
+    if (fs.existsSync(OUT_DIR)) {
+      fs.rmdirSync(OUT_DIR);
+    }
   },
 });