Add URLs for schemas and display them in CLI

* Presets and tests now have URL property that is displayed on the command line and that points to the offical documentation for the items they refer to.
* Multiple URLs can be displayed if a preset is made up of other presets.
*  Schema.org schemas link to the relevant page on https://schema.org (NB: uses HTTPS URLs to make it easier to open in browers that may not support HTTP URLs)

Would resolve #18 except this feature is not yet documented.

index.js

@@ -132,6 +132,7 @@ const _structuredDataTest = async (structuredData, options) => {
                 tests.push({
                   test: testPath,
                   schema: name,
+                  url: `https://schema.org/${name}`,
                   type: structuredDataType || 'any',
                   group: name,
                   groups: groups,
@@ -235,7 +236,7 @@ const _structuredDataTest = async (structuredData, options) => {
     })
 
     // This is a recursive function scoped to this function
-    const _addTestsFromPresets = (presets, structuredData, tests, testsSkipped, testGroups) => {
+    const _addTestsFromPresets = (presets, structuredData, tests, testsSkipped, testGroups, parentPresetUrl) => {
       presets.forEach(preset => {
         if (!preset)
           throw new Error(`Invalid preset specified`)
@@ -245,6 +246,8 @@ const _structuredDataTest = async (structuredData, options) => {
 
         const groups = (Array.isArray(testGroups)) ? testGroups.concat(preset.name) : [preset.name]
 
+        let presetUrl = preset.url || parentPresetUrl || null
+
         let ignorePreset = false
 
         if (preset.conditional) {
@@ -270,6 +273,12 @@ const _structuredDataTest = async (structuredData, options) => {
                 skipTest = true
             }
 
+            // If the test doesn't have an explict URL assigned to it but the preset does
+            // then assign the URL on the preset (which should point to documentation for
+            // preset) to the test, so it is easily acessible when displaying results.
+            if (!test.url && presetUrl)
+              test.url = presetUrl
+
             if (skipTest) {
               testsSkipped.push(test)
             } else {
@@ -279,9 +288,9 @@ const _structuredDataTest = async (structuredData, options) => {
         }
 
         // If the preset has other presets associated with it, apply them too.
-        if (preset.presets) {
-          _addTestsFromPresets(preset.presets, structuredData, tests, testsSkipped, groups)
-        }
+        if (preset.presets)
+          _addTestsFromPresets(preset.presets, structuredData, tests, testsSkipped, groups, presetUrl)
+
       })
     }
 
@@ -663,7 +672,13 @@ const getTestsFromPreset = (preset, structuredData, testGroup) => {
               test.groups = groups
               if (!test.description)
                 test.description = test.test.replace(/(.*)?\[\d\]\./, '').replace(/"/g, '')
-
+
+              // If the test doesn't have an explict URL assigned to it but the preset does
+              // then assign the URL on the preset (which should point to documentation for
+              // preset) to the test, so it is easily acessible when displaying results.
+              if (!test.url && preset.url)
+                test.url = preset.url
+
               tests.push(test)
             })
           })
@@ -674,6 +689,11 @@ const getTestsFromPreset = (preset, structuredData, testGroup) => {
     // If preset does not have a schema, then return only the tests in the preset
     preset.tests.forEach(test => {
       _setTestGroup(test, preset)
+      // If the test doesn't have an explict URL assigned to it but the preset does
+      // then assign the URL on the preset (which should point to documentation for
+      // preset) to the test, so it is easily acessible when displaying results.
+      if (!test.url && preset.url)
+        test.url = preset.url
       tests.push(test)
     })
   }

lib/cli.js

@@ -49,7 +49,9 @@ async function printTestResults(testResult, options) {
 
         console.log(
           `  ${testGroupName}`,
-          (numberOfTestsInGroup) ? info(`- ${percentageTestPassed}% (${testResultsGrouped[group].passed.length } passed, ${testResultsGrouped[group].failed.length} failed)`) : ''
+          (numberOfTestsInGroup) ? info(`- ${percentageTestPassed}% (${testResultsGrouped[group].passed.length } passed, ${testResultsGrouped[group].failed.length} failed)`) : '',
+          testResultsGrouped[group].urls ? chalk.grey(`${testResultsGrouped[group].urls.map(url => `\n  ${url}`)}`) : '',
+          "\n"
         )
 
         const showTestInfo = (test) => {

lib/group-test-results.js

@@ -8,13 +8,17 @@ const groupTestResults = (tests) => {
 
     if (!testResultsGrouped[testGroup]) {
       testResultsGrouped[testGroup] = {
+        urls: [],
         passed: [],
         optional: [],
         warnings: [],
         failed: [],
       }
     }
 
+    if (test.url && !testResultsGrouped[testGroup].urls.includes(test.url))
+      testResultsGrouped[testGroup].urls.push(test.url)
+
     if (test.optional) {
       if (!testResultsGrouped[testGroup].optional.includes(test))
         testResultsGrouped[testGroup].optional.push(test)

presets/facebook.js

@@ -2,6 +2,7 @@
 const Facebook = {
   name: 'Facebook',
   description: 'Suggested metatags for Facebook',
+  url: 'https://developers.facebook.com/docs/sharing/webmasters',
   tests: [
     { test: `"og:title"`, type: 'metatag', description: 'must have page title' },
     { test: `"og:type"`, type: 'metatag', description: 'must have page type' },

presets/google.js

@@ -20,6 +20,7 @@ const DiscussionForumPosting = require('./google/schemas/CreativeWork/SocialMedi
 const Google = {
   name: 'Google',
   description: 'Check for common markup used by Google',
+  url: 'https://developers.google.com/search/docs/guides/intro-structured-data',
   presets: [
     ...Object.keys(WebPage).map(schema => WebPage[schema]),
     ...Object.keys(ClaimReview).map(schema => ClaimReview[schema]),

presets/twitter.js

@@ -2,6 +2,7 @@
 const Twitter = {
   name: 'Twitter',
   description: 'Suggested metatags for Twitter',
+  url: 'https://developer.twitter.com/en/docs/tweets/optimize-with-cards',
   tests: [
     { test: `"twitter:card"`, type: 'metatag', description: 'must have card type' },
     { test: `"twitter:title"`, type: 'metatag', description: 'must have title' },