tools/doc: Add tests for the doJSON function

Addresses nodejs#5955 on GitHub. Check that when given valid markdown it produced
valid JSON with the expected schema.

tools/doc/tests/test_json.js

@@ -0,0 +1,82 @@
+'use strict';
+
+var assert = require('assert');
+var fs = require('fs');
+
+var json = require('../json.js');
+
+// Outputs valid json with the expected fields when given simple markdown
+function test_doJSON() {
+  // Test data is a list of objects with two properties.
+  // The file property is the file path.
+  // The json property is some json which will be generated by the doctool.
+  var testData = [
+    {
+      'file': 'tools/doc/tests/fixtures/sample_document.markdown',
+      'json': {
+        'source': 'foo',
+        'modules': [ { 'textRaw': 'Sample Markdown',
+                       'name': 'sample_markdown',
+                       'modules': [ { 'textRaw':'Seussian Rhymes',
+                                      'name': 'seussian_rhymes',
+                                      'desc': '<ol>\n<li>fish</li>\n<li>' +
+                                              '<p>fish</p>\n</li>\n<li>' +
+                                              '<p>Red fish</p>\n</li>\n' +
+                                              '<li>Blue fish</li>\n</ol>\n',
+                                      'type': 'module',
+                                      'displayName': 'Seussian Rhymes'
+                                   } ],
+                       'type': 'module',
+                       'displayName': 'Sample Markdown'
+                 } ]
+      }
+    },
+    {
+      'file': 'tools/doc/tests/fixtures/order_of_end_tags_5873.markdown',
+      'json': {
+        'source':'foo',
+        'modules': [ {
+          'textRaw': 'Title',
+          'name': 'title',
+          'modules': [ {
+            'textRaw': 'Subsection',
+            'name': 'subsection',
+            'classMethods': [ {
+              'textRaw': 'Class Method: Buffer.from(array)',
+              'type':'classMethod',
+              'name':'from',
+              'signatures': [ {
+                'params': [ {
+                  'textRaw': '`array` {Array} ',
+                  'name': 'array',
+                  'type': 'Array'
+                } ]
+              },
+                {
+                  'params' : [ {
+                    'name': 'array'
+                  } ]
+                }
+              ]
+            } ],
+            'type': 'module',
+            'displayName': 'Subsection'
+          } ],
+          'type': 'module',
+          'displayName': 'Title'
+        } ]
+      }
+    }
+  ];
+
+  testData.forEach(function(item) {
+    fs.readFile(item.file, 'utf8', function(err, input) {
+      json(input, 'foo', function(err, output) {
+        if (err) throw err;
+        assert.deepStrictEqual(output, item.json);
+      });
+    });
+  });
+}
+
+test_doJSON();