parse yaml frontmatter using an actual library

handle frontmatter with no markdown after it
test coverage for this scenario
tested annotations, pattern type/subtype markdown/yaml, and pattern markdown/yaml

close 396

Author: bmuenzenmeyer

core/lib/markdown_parser.js

@@ -1,6 +1,7 @@
 "use strict";
 
 var md = require('markdown-it')();
+var yaml = require('js-yaml');
 
 var markdown_parser = function () {
 
@@ -11,31 +12,23 @@ var markdown_parser = function () {
       //for each block process the yaml frontmatter and markdown
       var frontmatterRE = /---\r?\n{1}([\s\S]*)---\r?\n{1}([\s\S]*)+/gm;
       var chunks = frontmatterRE.exec(block);
-      if (chunks && chunks[1]) {
-
-        //convert each yaml frontmatter key / value into an object key
-        var frontmatter = chunks[1];
-        var frontmatterLines = frontmatter.split(/\n/gm);
-        for (var j = 0; j < frontmatterLines.length; j++) {
-
-          var frontmatterLine = frontmatterLines[j];
-          if (frontmatterLine.length > 0) {
-
-            var frontmatterLineChunks = frontmatterLine.split(':'); //test this
-            var frontmatterKey = frontmatterLineChunks[0].toLowerCase().trim();
-            var frontmatterValueString = frontmatterLineChunks[1].trim();
-
-            returnObject[frontmatterKey] = frontmatterValueString;
-          }
 
+      if (chunks) {
+        //we got some frontmatter
+        if (chunks && chunks[1]) {
+          //parse the yaml if we got it
+          var frontmatter = chunks[1];
+          returnObject = yaml.safeLoad(frontmatter);
         }
-      }
 
-      if (chunks && chunks[2]) {
-        //parse the actual markdown
-        returnObject.markdown = md.render(chunks[2]);
+        if (chunks[2]) {
+          //parse the actual markdown if it exists
+          returnObject.markdown = md.render(chunks[2]);
+        } else {
+          returnObject.markdown = '';
+        }
       } else {
-        //assume the passed in block is raw markdown
+        //assume the block was only markdown
         returnObject.markdown = md.render(block);
       }
     } catch (ex) {

package.json

@@ -7,6 +7,7 @@
     "diveSync": "^0.3.0",
     "fs-extra": "^0.30.0",
     "glob": "^7.0.0",
+    "js-yaml": "^3.6.1",
     "json5": "^0.5.0",
     "lodash": "~4.13.1",
     "markdown-it": "^6.0.1",

test/files/_patterns/00-test/03-styled-atom.md

@@ -0,0 +1,3 @@
+---
+status: inprogress
+---

test/files/nav.md

@@ -1,5 +1,5 @@
 ---
-el: #nav
+el: '#nav'
 title : Navigation
 ---
 Navigation for adaptive web experiences can be tricky. Refer to [these repsonsive patterns](https://bradfrost.github.io/this-is-responsive/patterns.html#navigation) when evaluating solutions.

test/markdown_parser_tests.js

@@ -2,34 +2,46 @@
 
 var path = require('path');
 var fs = require('fs-extra');
-var eol = require('os').EOL;
 var mp = require('../core/lib/markdown_parser');
 var markdown_parser = new mp();
 
 exports['markdown_parser'] = {
-	'parses pattern description block correctly when frontmatter not present' : function(test){
-		//arrange
+	'parses pattern description block correctly when frontmatter not present' : function(test) {
+    //arrange
     var markdownFileName = path.resolve("./test/files/_patterns/00-test/00-foo.md");
     var markdownFileContents = fs.readFileSync(markdownFileName, 'utf8');
 
-		//act
-		var returnObject = markdown_parser.parse(markdownFileContents)
+    //act
+    var returnObject = markdown_parser.parse(markdownFileContents);
 
-		//assert
+    //assert
     test.equals(returnObject.markdown, '<h2>A Simple Include</h2>\n<p>This pattern contains an include of <code>test-bar</code>. It also has this markdown file, which does not have frontmatter.</p>\n');
     test.done();
 	},
-  'parses pattern description block correctly when frontmatter present' : function(test){
+  'parses pattern description block correctly when frontmatter present' : function (test) {
     //arrange
     var markdownFileName = path.resolve("./test/files/_patterns/00-test/01-bar.md");
     var markdownFileContents = fs.readFileSync(markdownFileName, 'utf8');
 
     //act
-    var returnObject = markdown_parser.parse(markdownFileContents)
+    var returnObject = markdown_parser.parse(markdownFileContents);
 
     //assert
     test.equals(returnObject.markdown, '<h2>A Simple Bit of Markup</h2>\n<p>Foo cannot get simpler than bar, amiright?</p>\n');
     test.equals(returnObject.status, 'complete');
     test.done();
+  },
+  'parses frontmatter only when no markdown present': function (test) {
+    //arrange
+    var markdownFileName = path.resolve("./test/files/_patterns/00-test/03-styled-atom.md");
+    var markdownFileContents = fs.readFileSync(markdownFileName, 'utf8');
+
+    //act
+    var returnObject = markdown_parser.parse(markdownFileContents);
+
+    //assert
+    test.equals(returnObject.markdown, '');
+    test.equals(returnObject.status, 'inprogress');
+    test.done();
   }
 };