test(core): Move unit tests closer to testable components (no-changelog) (#10287)

packages/cli/test/shared/flushPromises.ts

@@ -0,0 +1,6 @@
+/**
+ * Ensure all pending promises settle. The promise's `resolve` is placed in
+ * the macrotask queue and so called at the next iteration of the event loop
+ * after all promises in the microtask queue have settled first.
+ */
+export const flushPromises = async () => await new Promise(setImmediate);