message: test: add check that language server is up and running.
diff: @@ -3,7 +3,7 @@ import { suite } from 'mocha';
  import * as path from 'path';
  import * as vscode from 'vscode';
  import * as fs from 'fs';
  -import { initLean4Untitled, initLean4, waitForInfoviewHtml, closeAllEditors,
  +import { initLean4Untitled, initLean4, waitForInfoviewHtml, closeAllEditors, sleep
  extractPhrase, restartLeanServer, assertStringInInfoview, resetToolchain, insertText } from '../utils/helpers';
  // Expects to be launched with folder: ${workspaceFolder}/vscode-lean4/test/suite/simple
  @@ -13,17 +13,20 @@ suite('Toolchain Test Suite', () => {
  console.log('=================== Test worker crashed and client running ===================');
  void vscode.window.showInformationMessage('Running tests: ' + __dirname);
  - // initializing string that causes the worker to fail
  -
  - const lean = await initLean4Untitled('#eval Lean.versionString');
  + const hello = 'Hello World'
  + const lean = await initLean4Untitled(`#eval "${hello}"`);
  const info = lean.exports.infoProvider;
  assert(info, 'No InfoProvider export');
  - console.log('Insert eval that causes crash.')
  - await insertText('#eval (unsafeCast 0 : String)')
  + console.log('make sure language server is up and running.');
  + await assertStringInInfoview(info, hello);
  - const expectedMessage = 'Lean worker exited or crashed: '
  + await sleep(20000);
  +
  + console.log('Insert eval that causes crash.')
  + await insertText('\n\n#eval (unsafeCast 0 : String)')
  + const expectedMessage = 'Lean worker exited or crashed'
  await assertStringInInfoview(info, expectedMessage);
  }).timeout(60000);
  