feat(challenge-md): Parse solutions from md

tools/challenge-md-parser/__snapshots__/solution-to-data.test.js.snap

@@ -0,0 +1,14 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`challengeSeed-to-data plugin should have an output to match the snapshot 1`] = `
+Object {
+  "solutions": Array [
+    "function testFunction(arg) {
+  return arg;
+}
+
+testFunction('hello');
+",
+  ],
+}
+`;

tools/challenge-md-parser/solution-to-data.js

@@ -0,0 +1,20 @@
+const visit = require('unist-util-visit');
+const { selectAll } = require('hast-util-select');
+
+const { sectionFilter } = require('./utils');
+
+function createPlugin() {
+  return function transformer(tree, file) {
+    function visitor(node) {
+      if (sectionFilter(node, 'solution')) {
+        const solutions = selectAll('code', node).map(
+          element => element.children[0].value
+        );
+        file.data.solutions = solutions;
+      }
+    }
+    visit(tree, 'element', visitor);
+  };
+}
+
+module.exports = createPlugin;

tools/challenge-md-parser/solution-to-data.test.js

@@ -0,0 +1,37 @@
+/* global describe it expect beforeEach */
+const mockAST = require('./fixtures/challenge-html-ast.json');
+const solutionToData = require('./solution-to-data');
+
+describe('challengeSeed-to-data plugin', () => {
+  const plugin = solutionToData();
+  let file = { data: {} };
+
+  beforeEach(() => {
+    file = { data: {} };
+  });
+
+  it('returns a function', () => {
+    expect(typeof plugin).toEqual('function');
+  });
+
+  it('adds a `solutions` property to `file.data`', () => {
+    plugin(mockAST, file);
+    expect('solutions' in file.data).toBe(true);
+  });
+
+  it('ensures that the `solutions` property is an array', () => {
+    plugin(mockAST, file);
+    expect(Array.isArray(file.data.solutions)).toBe(true);
+  });
+
+  it('each entry in the `solutions` array is a string', () => {
+    plugin(mockAST, file);
+
+    expect(file.data.solutions.every(el => typeof el === 'string')).toBe(true);
+  });
+
+  it('should have an output to match the snapshot', () => {
+    plugin(mockAST, file);
+    expect(file.data).toMatchSnapshot();
+  });
+});

tools/challenge-md-parser/text-to-data.js

@@ -1,7 +1,7 @@
 const visit = require('unist-util-visit');
 const toHTML = require('hast-util-to-html');
 
-const { sectionFilter } = require('./utils')
+const { sectionFilter } = require('./utils');
 
 function textToData(sectionIds) {
   if (!sectionIds || !Array.isArray(sectionIds) || sectionIds.length <= 0) {