feat(parser): enforce workshop file validations (#66340)

Co-authored-by: sembauke <semboot699@gmail.com>

tools/challenge-parser/parser/__fixtures__/workshop-test-steps/step-1.md

@@ -0,0 +1,19 @@
+---
+id: abc123
+title: Step 1
+challengeType: 28
+---
+
+# --description--
+
+Some description.
+
+# --hints--
+```js
+assert(true);
+```
+
+# --solutions--
+```js
+var x = 1;
+```

tools/challenge-parser/parser/__fixtures__/workshop-test-steps/step-2.md

@@ -0,0 +1,14 @@
+---
+id: abc456
+title: Step 2
+challengeType: 28
+---
+
+# --description--
+
+Some description.
+
+# --hints--
+```js
+assert(true);
+```

tools/challenge-parser/parser/__fixtures__/workshop-test-steps/step-with-four-erms.md

@@ -0,0 +1,22 @@
+---
+id: abc789
+title: Step 1
+challengeType: 28
+---
+
+# --description--
+
+Some description.
+
+# --seed--
+
+## --seed-contents--
+```html
+--fcc-editable-region--
+<p>First region</p>
+--fcc-editable-region--
+<p>Middle</p>
+--fcc-editable-region--
+<p>Second region</p>
+--fcc-editable-region--
+```

tools/challenge-parser/parser/__fixtures__/workshop-upcoming-test-steps/step-1.md

@@ -0,0 +1,9 @@
+---
+id: step-1
+title: Step 1
+challengeType: 28
+---
+
+# --description--
+
+Placeholder fixture for parser path resolution tests.

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

@@ -4,8 +4,14 @@ const visitChildren = require('unist-util-visit-children');
 const { getSection } = require('./utils/get-section');
 const { getFileVisitor } = require('./utils/get-file-visitor');
 
+const path = require('path');
+
 const editableRegionMarker = '--fcc-editable-region--';
 
+function isWorkshop(file) {
+  return file.path && file.path.includes(path.sep + 'workshop-');
+}
+
 function findRegionMarkers(challengeFile) {
   const lines = challengeFile.contents.split('\n');
   const editableLines = lines
@@ -56,8 +62,13 @@ function addSeeds() {
     };
 
     // process region markers - remove them from content and add them to data
+    let totalEditableRegionMarkers = 0;
+
     const challengeFiles = Object.values(seeds).map(data => {
       const seed = { ...data };
+      // Per-file check: ensures no single seed file has more than 2 markers.
+      // This is distinct from the workshop-level check below, which enforces
+      // exactly 2 total markers across all seed files combined.
       const editRegionMarkers = findRegionMarkers(seed);
       if (editRegionMarkers) {
         seed.contents = removeLines(seed.contents, editRegionMarkers);
@@ -66,12 +77,19 @@ function addSeeds() {
           throw Error('Editable region must be non zero');
         }
         seed.editableRegionBoundaries = editRegionMarkers;
+        totalEditableRegionMarkers += editRegionMarkers.length;
       } else {
         seed.editableRegionBoundaries = [];
       }
       return seed;
     });
 
+    if (isWorkshop(file) && totalEditableRegionMarkers !== 2) {
+      throw Error(
+        `Workshop challenge ${file.path} must have exactly 2 editable region markers`
+      );
+    }
+
     file.data = {
       ...file.data,
       challengeFiles
@@ -108,3 +126,4 @@ function validateEditableMarkers({ value, position }) {
 
 module.exports = addSeeds;
 module.exports.editableRegionMarker = editableRegionMarker;
+module.exports.isWorkshop = isWorkshop;

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

@@ -1,8 +1,10 @@
 const { isEmpty } = require('lodash');
 const { root } = require('mdast-builder');
 const visitChildren = require('unist-util-visit-children');
+const fs = require('fs');
+const path = require('path');
 
-const { editableRegionMarker } = require('./add-seed');
+const { editableRegionMarker, isWorkshop } = require('./add-seed');
 const { getSection } = require('./utils/get-section');
 const { getFileVisitor } = require('./utils/get-file-visitor');
 const { splitOnThematicBreak } = require('./utils/split-on-thematic-break');
@@ -16,6 +18,52 @@ function validateMarkers({ value }) {
     );
 }
 
+function isLastStep(file) {
+  const challengeDir = path.dirname(file.path);
+  const blockName = path.basename(challengeDir);
+
+  let current = challengeDir;
+  let blockJsonPath = null;
+
+  for (let i = 0; i < 10; i++) {
+    current = path.dirname(current);
+    const candidate = path.join(
+      current,
+      'structure',
+      'blocks',
+      `${blockName}.json`
+    );
+    if (fs.existsSync(candidate)) {
+      blockJsonPath = candidate;
+      break;
+    }
+  }
+
+  if (!blockJsonPath) return true;
+
+  try {
+    const blockData = JSON.parse(fs.readFileSync(blockJsonPath, 'utf8'));
+
+    // Upcoming blocks may still contain transitional content that does not yet
+    // follow this invariant.
+    if (blockData.isUpcomingChange) {
+      return true;
+    }
+
+    const challengeOrder = blockData.challengeOrder;
+
+    if (!Array.isArray(challengeOrder) || challengeOrder.length === 0) {
+      return true;
+    }
+
+    const currentId = path.basename(file.path, '.md');
+    const lastId = challengeOrder[challengeOrder.length - 1].id;
+
+    return currentId === lastId;
+  } catch {
+    return true;
+  }
+}
 function createPlugin() {
   return function transformer(tree, file) {
     const solutionArrays = splitOnThematicBreak(
@@ -34,6 +82,30 @@ function createPlugin() {
       if (!isEmpty(solution)) solutions.push(Object.values(solution));
     });
 
+    if (isWorkshop(file)) {
+      const seedSection = getSection(tree, `--seed--`);
+      const seedContents = getSection(root(seedSection), `--seed-contents--`);
+      let totalMarkers = 0;
+      const seedTree = root(seedContents);
+      seedTree.children.forEach(node => {
+        if (node.value) {
+          const lines = node.value.split('\n');
+          lines.forEach(line => {
+            if (line.trim() === '--fcc-editable-region--') totalMarkers++;
+          });
+        }
+      });
+      if (totalMarkers > 0 && totalMarkers !== 2) {
+        throw Error(
+          `Workshop challenge ${file.path} must have exactly 2 editable region markers`
+        );
+      }
+      if (solutions.length > 0 && !isLastStep(file)) {
+        throw Error(
+          `Workshop challenge ${file.path} has solutions but is not the last step.`
+        );
+      }
+    }
     file.data = {
       ...file.data,
       solutions: solutions

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

@@ -1,3 +1,4 @@
+import path from 'path';
 import { describe, beforeAll, beforeEach, it, expect } from 'vitest';
 import { isObject } from 'lodash';
 import parseFixture from '../__fixtures__/parse-fixture';
@@ -94,4 +95,33 @@ describe('add solution plugin', () => {
     plugin(mockAST, file);
     expect(file.data).toMatchSnapshot();
   });
+  it('should throw if a workshop non-last step has solutions', async () => {
+    expect.assertions(1);
+    const workshopNonLastAST = await parseFixture('with-multiple-solns.md');
+    const workshopFile = {
+      data: {},
+      path: path.join(
+        __dirname,
+        '../__fixtures__/workshop-test-steps/step-1.md'
+      )
+    };
+    expect(() => plugin(workshopNonLastAST, workshopFile)).toThrow(
+      'has solutions but is not the last step'
+    );
+  });
+
+  it('should allow solutions in non-last steps for upcoming workshop blocks', async () => {
+    expect.assertions(1);
+    const workshopNonLastAST = await parseFixture('with-multiple-solns.md');
+    const upcomingWorkshopFile = {
+      data: {},
+      path: path.join(
+        __dirname,
+        '../__fixtures__/workshop-upcoming-test-steps/step-1.md'
+      )
+    };
+    expect(() =>
+      plugin(workshopNonLastAST, upcomingWorkshopFile)
+    ).not.toThrow();
+  });
 });

tools/challenge-parser/structure/blocks/workshop-test-steps.json

@@ -0,0 +1,9 @@
+{
+  "dashedName": "workshop-test-steps",
+  "blockLabel": "workshop",
+  "challengeOrder": [
+    { "id": "step-1", "title": "Step 1" },
+    { "id": "step-with-four-erms", "title": "Step with four erms" },
+    { "id": "step-2", "title": "Step 2" }
+  ]
+}

tools/challenge-parser/structure/blocks/workshop-upcoming-test-steps.json

@@ -0,0 +1,9 @@
+{
+  "isUpcomingChange": true,
+  "dashedName": "workshop-upcoming-test-steps",
+  "blockLabel": "workshop",
+  "challengeOrder": [
+    { "id": "step-1", "title": "Step 1" },
+    { "id": "step-2", "title": "Step 2" }
+  ]
+}