test: enable tests for steps (#44550)

* fix: handle missing solutions correctly

Rather than creating an [[]] the parser now creates [] which isEmpty().
This makes the test suite check the next challenge for a solution.

In addition, the logic for testing solutions was fixed.

* chore: update snapshots

* test: build new superblock in node.js-tests CI

* test: allow forward slash in superblock slug

* fix: borked tests oops

* test: ignore duplicated projects

* fix: i did not break these shaun did :)

* fix: idIndex is index of id not id

Co-authored-by: Nicholas Carrigan <nhcarrigan@gmail.com>

tools/challenge-parser/parser/__snapshots__/index.acceptance.test.js.snap

@@ -12,9 +12,7 @@ Object {
 a container directive
 :::</p>
 </section>",
-  "solutions": Array [
-    Array [],
-  ],
+  "solutions": Array [],
   "tests": Array [],
 }
 `;
@@ -43,9 +41,7 @@ Object {
 <pre><code class=\\"language-js\\">  var x = 'y';
 </code></pre>",
   },
-  "solutions": Array [
-    Array [],
-  ],
+  "solutions": Array [],
   "tests": Array [],
 }
 `;
@@ -100,9 +96,7 @@ for (let index = 0; index < array.length; index++) {
 <pre><code class=\\"language-html\\">code example 0
 </code></pre>
 </section>",
-  "solutions": Array [
-    Array [],
-  ],
+  "solutions": Array [],
   "tests": Array [
     Object {
       "testString": "// test code",
@@ -166,9 +160,7 @@ Object {
 <pre><code class=\\"language-html\\">code example 0
 </code></pre>
 </section>",
-  "solutions": Array [
-    Array [],
-  ],
+  "solutions": Array [],
   "tests": Array [
     Object {
       "testString": "// test code",
@@ -516,9 +508,7 @@ Object {
   "forumTopicId": 18276,
   "id": "bd7123c8c441eddfaeb5bdef",
   "isHidden": false,
-  "solutions": Array [
-    Array [],
-  ],
+  "solutions": Array [],
   "tests": Array [
     Object {
       "testString": "// test code",

tools/challenge-parser/parser/plugins/add-solution.js

@@ -1,3 +1,4 @@
+const { isEmpty } = require('lodash');
 const { root } = require('mdast-builder');
 const visitChildren = require('unist-util-visit-children');
 
@@ -30,7 +31,7 @@ function createPlugin() {
       );
 
       visitForContents(solutionTree);
-      solutions.push(Object.values(solution));
+      if (!isEmpty(solution)) solutions.push(Object.values(solution));
     });
 
     file.data = {