refactor(tests): Migrate generator tests to import shims; delete bootstrap.js (#7414)

* refactor(tests): Use shims instead of bootstrap to load Blockly

  - Modify tests/generators/index.html to import the test shims
    instead of using bootstrap.js to load Blockly.

  - Modify test/generators/webdriver.js to have it wait for the
    workspace to exist before calling loadSelected().  There was
    previously a race which index.html had been winning, but
    now webdriver.js is winning (and the tests failing because
    there is no workspace yet when start() is called.

* chore(tests): Delete bootstrap.js etc.

  - Delete bootstrap.js, bootstrap_helper.js, and bootstrap_done.mjs.
  - Remove remaining references to bootstrap.js

* refactor(build): Remove deps npm script

  buildDeps is now only needed by buildCompiled, not ever for
  runnning in uncompressed mode, so:

  - Remove the deps gulp task (and the deps npm script.
  - Have the minify task run buildJavaScript and buildDeps directly.

  Additionally, the buildAdvanceCompilationTest target hasn't
  needed deps.js for some time (if ever), so skip having it run
  buildDeps entirely.

* refactor(build): Repatriate DEPS_FILE to build_tasks.js

  Since this is no longer used anywhere else it doesn't need to
  live in common.js.

* fix(scripts): Remove vestigial references to deps.mocha.js

* docs(tests): Add additional explanatory note

tests/generators/index.html

@@ -4,20 +4,12 @@
 <meta charset="utf-8">
 <title>Blockly Generator Tests</title>
 <script>
-  var BLOCKLY_BOOTSTRAP_OPTIONS = {
-    scripts: [
-      'build/msg/en.js',
-      'tests/generators/unittest_javascript.js',
-      'tests/generators/unittest_python.js',
-      'tests/generators/unittest_php.js',
-      'tests/generators/unittest_lua.js',
-      'tests/generators/unittest_dart.js',
-      'tests/generators/unittest.js',
-    ],
-  }
-</script>
-<script src="../bootstrap.js"></script>
-<script>
+// N.B.: This script depends on the following (module) script to load
+// Blockly, the code generators, and the unittest*.js scripts.  The
+// module script actually gets executed after this one, so although
+// Blockly will be available when the defined global functions are
+// called it isn't yet available when this script runs.
+
 var demoWorkspace = null;
 
 function start() {
@@ -199,9 +191,31 @@ function changeIndex() {
   demoWorkspace.getToolbox().flyout_.workspace_.options.oneBasedIndex = oneBasedIndex;
 }
 </script>
+
 <script type="module">
-// Wait for Blockly to finish loading before running tests.
-import '../bootstrap_done.mjs';
+import {loadScript} from '../scripts/load.mjs';
+
+import * as Blockly from '../../build/blockly.loader.mjs';
+import '../../build/blocks.loader.mjs';
+import {dartGenerator} from '../../build/dart.loader.mjs';
+import {luaGenerator} from '../../build/lua.loader.mjs';
+import {javascriptGenerator} from '../../build/javascript.loader.mjs';
+import {phpGenerator} from '../../build/php.loader.mjs';
+import {pythonGenerator} from '../../build/python.loader.mjs';
+
+globalThis.dartGenerator = dartGenerator;
+globalThis.luaGenerator = luaGenerator;
+globalThis.javascriptGenerator = javascriptGenerator;
+globalThis.phpGenerator = phpGenerator;
+globalThis.pythonGenerator = pythonGenerator;
+
+await loadScript('../../build/msg/en.js');
+await loadScript('./unittest_javascript.js');
+await loadScript('./unittest_python.js');
+await loadScript('./unittest_php.js');
+await loadScript('./unittest_lua.js');
+await loadScript('./unittest_dart.js');
+await loadScript('./unittest.js');
 
 start();
 </script>

tests/generators/webdriver.js

@@ -73,6 +73,10 @@ async function runGeneratorsInBrowser(outputDir) {
   console.log('Loading url: ' + url);
   await browser.url(url);
 
+  await browser
+    .$('.blocklySvg .blocklyWorkspace > .blocklyBlockCanvas')
+    .waitForExist({timeout: 2000});
+
   await browser.execute(function() {
     checkAll();
     loadSelected();