fix(cli-repl): disregard autocomplete eval for input stream MONGOSH-586 (#660)

This is the second half of MONGOSH-586.

The REPL’s built-in autocompleter uses `repl.eval()` to figure out
what JS object’s properties it would be autocompleting. These
`.eval()` calls don’t represent a state change as far as input
handling is concerned, so they should not affect the prompt and not
enable block-on-newline.

Author: addaleax

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

@@ -9,6 +9,7 @@ import { StubbedInstance, stubInterface } from 'ts-sinon';
 import { promisify } from 'util';
 import { expect, fakeTTYProps, tick, useTmpdir, waitEval } from '../test/repl-helpers';
 import MongoshNodeRepl, { MongoshConfigProvider, MongoshNodeReplOptions } from './mongosh-repl';
+import stripAnsi from 'strip-ansi';
 
 const delay = promisify(setTimeout);
 
@@ -235,6 +236,19 @@ describe('MongoshNodeRepl', () => {
       expect(output).to.include('65537');
     });
 
+    it('does not stop input when autocompleting during .editor', async() => {
+      input.write('.editor\n');
+      await tick();
+      expect(output).to.include('Entering editor mode');
+      output = '';
+      input.write('db.\u0009\u0009');
+      await tick();
+      input.write('version()\n');
+      input.write('\u0004'); // Ctrl+D
+      await waitEval(bus);
+      expect(output).to.include('Error running command serverBuildInfo');
+    });
+
     it('can enter multiline code', async() => {
       for (const line of multilineCode.split('\n')) {
         input.write(line + '\n');
@@ -298,6 +312,20 @@ describe('MongoshNodeRepl', () => {
         await tick();
         expect(output).to.include('somelongvariable');
       });
+      it('autocompletion during .editor does not reset the prompt', async() => {
+        input.write('.editor\n');
+        await tick();
+        output = '';
+        expect((mongoshRepl.runtimeState().repl as any)._prompt).to.equal('');
+        input.write('db.\u0009\u0009');
+        await tick();
+        input.write('foo\nbar\n');
+        expect((mongoshRepl.runtimeState().repl as any)._prompt).to.equal('');
+        input.write('\u0003'); // Ctrl+C for abort
+        await tick();
+        expect((mongoshRepl.runtimeState().repl as any)._prompt).to.equal('> ');
+        expect(stripAnsi(output)).to.equal('ddbdb.db.\tdb.\tfdb.\tfodb.\tfoo\r\nbbabar\r\n\r\n> ');
+      });
     });
 
     context('history support', () => {

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

@@ -65,6 +65,7 @@ class MongoshNodeRepl implements EvaluationListener {
   shellCliOptions: Partial<MongoshCliOptions>;
   configProvider: MongoshConfigProvider;
   onClearCommand?: EvaluationListener['onClearCommand'];
+  insideAutoComplete: boolean;
 
   constructor(options: MongoshNodeReplOptions) {
     this.input = options.input;
@@ -74,6 +75,7 @@ class MongoshNodeRepl implements EvaluationListener {
     this.nodeReplOptions = options.nodeReplOptions || {};
     this.shellCliOptions = options.shellCliOptions || {};
     this.configProvider = options.configProvider;
+    this.insideAutoComplete = false;
     this._runtimeState = null;
   }
 
@@ -123,16 +125,21 @@ class MongoshNodeRepl implements EvaluationListener {
       completer.bind(null, internalState.getAutocompleteParameters());
     (repl as Mutable<typeof repl>).completer =
       callbackify(async(text: string): Promise<[string[], string]> => {
-        // Merge the results from the repl completer and the mongosh completer.
-        const [ [replResults], [mongoshResults] ] = await Promise.all([
-          (async() => await origReplCompleter(text) || [[]])(),
-          (async() => await mongoshCompleter(text))()
-        ]);
-        this.bus.emit('mongosh:autocompletion-complete'); // For testing.
-        // Remove duplicates, because shell API methods might otherwise show
-        // up in both completions.
-        const deduped = [...new Set([...replResults, ...mongoshResults])];
-        return [deduped, text];
+        this.insideAutoComplete = true;
+        try {
+          // Merge the results from the repl completer and the mongosh completer.
+          const [ [replResults], [mongoshResults] ] = await Promise.all([
+            (async() => await origReplCompleter(text) || [[]])(),
+            (async() => await mongoshCompleter(text))()
+          ]);
+          this.bus.emit('mongosh:autocompletion-complete'); // For testing.
+          // Remove duplicates, because shell API methods might otherwise show
+          // up in both completions.
+          const deduped = [...new Set([...replResults, ...mongoshResults])];
+          return [deduped, text];
+        } finally {
+          this.insideAutoComplete = false;
+        }
       });
 
     const originalDisplayPrompt = repl.displayPrompt.bind(repl);
@@ -284,13 +291,18 @@ class MongoshNodeRepl implements EvaluationListener {
   }
 
   async eval(originalEval: asyncRepl.OriginalEvalFunction, input: string, context: any, filename: string): Promise<any> {
-    this.lineByLineInput.enableBlockOnNewLine();
+    if (!this.insideAutoComplete) {
+      this.lineByLineInput.enableBlockOnNewLine();
+    }
+
     const { internalState, repl, shellEvaluator } = this.runtimeState();
 
     try {
       return await shellEvaluator.customEval(originalEval, input, context, filename);
     } finally {
-      repl.setPrompt(await this.getShellPrompt(internalState));
+      if (!this.insideAutoComplete) {
+        repl.setPrompt(await this.getShellPrompt(internalState));
+      }
       this.bus.emit('mongosh:eval-complete'); // For testing purposes.
     }
   }