feat(cli-repl): mark exceptions from mongoshrc as such MONGOSH-911 (#1027)

Author: addaleax

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

@@ -388,6 +388,14 @@ describe('CliRepl', () => {
           await cliRepl.start('', {});
           expect(output).to.include('reached five');
         });
+
+        it('if an exception is thrown, indicates that it comes from mongoshrc', async() => {
+          await fs.writeFile(path.join(tmpdir.path, '.mongoshrc.js'), 'throw new Error("bananas")');
+          cliRepl = new CliRepl(cliReplOptions);
+          await cliRepl.start('', {});
+          expect(output).to.include('Error while running ~/.mongoshrc.js:');
+          expect(output).to.include('Error: bananas');
+        });
       });
 
       context('files loaded from command line', () => {

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

@@ -240,6 +240,7 @@ class CliRepl {
         this.bus.emit('mongosh:mongoshrc-load');
         await this.mongoshRepl.loadExternalFile(mongoshrcPath);
       } catch (err) {
+        this.output.write(this.clr('Error while running ~/.mongoshrc.js:\n', ['bold', 'yellow']));
         this.output.write(this.mongoshRepl.writer(err) + '\n');
       }
       return;