better event based waiting

Author: lerouxb

packages/cli-repl/src/mongosh-repl.spec.ts

@@ -20,6 +20,7 @@ import {
   tick,
   useTmpdir,
   waitEval,
+  waitMongoshCompletionResults,
 } from '../test/repl-helpers';
 import type { MongoshIOProvider, MongoshNodeReplOptions } from './mongosh-repl';
 import MongoshNodeRepl from './mongosh-repl';
@@ -364,12 +365,7 @@ describe('MongoshNodeRepl', function () {
     const tabtab = async () => {
       await tab();
       if (process.env.USE_NEW_AUTOCOMPLETE) {
-        // TODO: This is because autocomplete() is async and will either list
-        // databases or collections or sample documents, any of which takes time
-        // to complete and can time out. There is probably a better way.
-        await new Promise((resolve) => {
-          setTimeout(resolve, 210);
-        });
+        await waitMongoshCompletionResults(bus);
       }
       await tab();
     };

packages/cli-repl/src/mongosh-repl.ts

@@ -548,7 +548,11 @@ class MongoshNodeRepl implements EvaluationListener {
           }
         })(),
       ]);
-      this.bus.emit('mongosh:autocompletion-complete'); // For testing.
+      this.bus.emit(
+        'mongosh:autocompletion-complete',
+        replResults,
+        mongoshResults
+      ); // For testing.
 
       // Sometimes the mongosh completion knows that what it is doing is right,
       // and that autocompletion based on inspecting the actual objects that

packages/cli-repl/test/repl-helpers.ts

@@ -75,6 +75,25 @@ async function waitCompletion(bus: MongoshBus) {
   await tick();
 }
 
+async function waitMongoshCompletionResults(bus: MongoshBus) {
+  // Waiting for the completion results can "time out" if an async action such
+  // as listing the databases or collections or loading the schema takes longer
+  // than 200ms (at the time of writing), but by the next try or at least
+  // eventually the action should complete and then the next autocomplete call
+  // will return the cached result.
+  let found = false;
+  while (!found) {
+    const [, mongoshResults] = await waitBus(
+      bus,
+      'mongosh:autocompletion-complete'
+    );
+    if (mongoshResults.length === 0) {
+      found = true;
+    }
+  }
+  await tick();
+}
+
 const fakeTTYProps: Partial<ReadStream & WriteStream> = {
   isTTY: true,
   isRaw: true,
@@ -106,6 +125,7 @@ export {
   waitBus,
   waitEval,
   waitCompletion,
+  waitMongoshCompletionResults,
   fakeTTYProps,
   readReplLogFile,
 };

packages/types/src/index.ts

@@ -335,7 +335,10 @@ export interface MongoshBusEventsMap extends ConnectEventMap {
    * Signals the completion of the autocomplete suggestion providers.
    * _ONLY AVAILABLE FOR TESTING._
    */
-  'mongosh:autocompletion-complete': () => void;
+  'mongosh:autocompletion-complete': (
+    resplResults: string[],
+    mongoshResults: string[]
+  ) => void;
   /**
    * Signals the completion of the asynchronous interrupt handler in MongoshRepl. Not fired for interrupts of _synchronous_ code.
    * _ONLY AVAILABLE FOR TESTING._