feat(markdown): add YAML frontmatter support

cli.js

@@ -163,7 +163,7 @@ readdirp.promise(schemaPath, { root: schemaPath, fileFilter: `*.${schemaExtensio
     generate,
 
     // generate Markdown ASTs
-    build,
+    build({}),
 
     // build readme
     readme({
@@ -177,6 +177,7 @@ readdirp.promise(schemaPath, { root: schemaPath, fileFilter: `*.${schemaExtensio
       info,
       error,
       debug,
+      meta: argv.m
     }),
   ))
 

lib/markdownBuilder.js

@@ -11,17 +11,21 @@
  */
 const { each, values } = require('ferrum');
 const {
-  root, paragraph, text, heading,
+  root, paragraph, text, heading, brk, separator
 } = require('mdast-builder');
 
-function build(schemas) {
+function build({ }) {
+
+
+  return (schemas) => {
   // eslint-disable-next-line no-return-assign, no-param-reassign
-  each(values(schemas), schema => schema.markdown = root([
+    each(values(schemas), schema => schema.markdown = root([
     // todo add more elements
-    heading(1, text(schema.title)),
-    paragraph(text('This is a schema.')),
-  ]));
-  return schemas;
+      heading(1, text(schema.title)),
+      paragraph(text('This is a schema.')),
+    ]));
+    return schemas;
+  };
 }
 
 module.exports = build;

lib/writeMarkdown.js

@@ -15,9 +15,10 @@ const unified = require('unified');
 const path = require('path');
 const inspect = require('unist-util-inspect');
 const fs = require('fs-extra');
+const yaml = require('js-yaml');
 
 function writeMarkdown({
-  out, debug, error, info,
+  out, debug, error, info, meta
 }) {
   const dbg = (message) => {
     if (debug && typeof message === 'object') {
@@ -35,8 +36,18 @@ function writeMarkdown({
   return (schemas) => {
     each(pairs(schemas), ([name, schema]) => {
       dbg(schema.markdown);
-      const fileName = path.resolve(out, `${name}.md`);
-      fs.writeFile(fileName, processor.stringify(schema.markdown), (err) => {
+      const fileName = path.resolve(out, `${name}.schema.md`);
+
+      const output = 
+        // add YAML frontmatter
+        (!meta ? '' : '---\n') + 
+        (!meta ? '' : yaml.safeDump(meta)) + 
+        (!meta ? '' : '---\n\n') + 
+
+        processor.stringify(schema.markdown);
+
+
+      fs.writeFile(fileName, output, (err) => {
         if (err) {
           error(err);
         }

package.json

@@ -22,6 +22,7 @@
     "ferrum": "^1.4.1",
     "github-slugger": "^1.2.1",
     "i18next": "^19.0.1",
+    "js-yaml": "^3.13.1",
     "json-pointer": "^0.6.0",
     "mdast-builder": "^1.1.1",
     "mdast-util-to-string": "^1.0.7",