Add HTML validation utility

README.md

@@ -66,7 +66,7 @@ Instead of building and serving, you can run `gatsby develop` and point your bro
 
 The entire text for the book is in the _src/book.md_ file. Everything under _src/md/pages_ is auto-generated and any changes there will be lost.
 
-There are various npm script commands to help with building:
+There are various npm script commands to help with building and testing:
 
   - `npm run clean` runs `gatsby clean`.
     - Do this after adding new graphics or if anything weird happens.
@@ -79,6 +79,8 @@ There are various npm script commands to help with building:
     - Visit http://localhost:9000/bellatrix/ to see the result.
   - `npm run links` checks external links.
     - Checking links to GitHub it will fail due to rate-limiting unless you supply GitHub credentials.
+  - `npm run spell` can be used to maintain the list of spellings.
+  - `npm run valid` submits a page to the [W3C markup validation service](https://validator.w3.org/) and lists any issues above `info` level.
 
 ## How to
 

bin/util/validate.js

@@ -0,0 +1,20 @@
+const axios = require('axios')
+const fs=require('fs')
+
+module.exports.validateHtml = (fileName) => {
+
+  const file = fs.readFileSync(fileName)
+
+  axios({
+    method: 'post',
+    url: 'https://validator.w3.org/nu/?out=json',
+    data: file,
+    headers: {
+      'Content-Type': 'text/html'
+    },
+    maxContentLength: Infinity,
+    maxBodyLength: Infinity
+  }).then(function (response) {
+    console.log(response.data.messages.filter(m => m.type !== 'info'));
+  })
+}

package.json

@@ -6,14 +6,15 @@
   "author": "Ben Edgington",
   "keywords": [],
   "scripts": {
-    "develop": "gatsby develop",
+    "devel": "gatsby develop",
     "start": "gatsby develop",
     "build": "gatsby build --prefix-paths",
     "serve": "gatsby serve --prefix-paths",
     "clean": "gatsby clean",
     "check": "node -e 'require(\"./bin/build/prebuild\").runChecks()'",
     "links": "bin/util/urlcheck.sh src/book.md",
-    "spell": "bin/util/check_spellings_list.sh"
+    "spell": "bin/util/check_spellings_list.sh",
+    "valid": "node -e 'require(\"./bin/util/validate\").validateHtml(\"public/index.html\")'"
   },
   "dependencies": {
     "gatsby": "^4.24.4",