frontend: Add linting for ts code

internal/dis/component/server/assets/src/lib/discard.ts

@@ -0,0 +1,13 @@
+import { Mutex, MutexInterface } from 'async-mutex'
+
+const error = console.error.bind(console)
+
+/** discard discards the result of a promise, or logs an error if it occurs */
+export function discard<T> (p: Promise<T>): void {
+  p.then((): void => {}).catch(error)
+}
+
+/** runs worker exclusively on m, and discards the resulting promise */
+export function runMutexExclusive<T> (m: Mutex, worker: MutexInterface.Worker<T>): void {
+  discard(m.runExclusive(worker))
+}