feat: add blog loader

lib/loader/blog.js

@@ -0,0 +1,52 @@
+const fs = require('fs-extra');
+const path = require('path');
+const fm = require('front-matter');
+const globby = require('globby');
+const indexRE = /(^|.*\/)index\.md$/i;
+const extRE = /\.md$/;
+
+function fileToPath(file) {
+  if (indexRE.test(file)) {
+    // index.md -> /
+    // foo/index.md -> /foo/
+    return file.replace(indexRE, '/$1');
+  } else {
+    // foo.md -> /foo.html
+    // foo/bar.md -> /foo/bar.html
+    return `/${file.replace(extRE, '').replace(/\\/g, '/')}.html`;
+  }
+}
+
+function parse(fileString) {
+  if (!fm.test(fileString)) {
+    return {metadata: null, content: fileString};
+  }
+  const {attributes: metadata, body: content} = fm(fileString);
+
+  return {metadata, content};
+}
+
+async function loadBlog(sourceDir) {
+  const blogFiles = await globby(['**/*.md', '!.blogi', '!node_modules'], {
+    cwd: sourceDir
+  });
+
+  const blogDatas = await Promise.all(
+    blogFiles.map(async file => {
+      const filepath = path.resolve(sourceDir, file);
+      const fileString = await fs.readFile(filepath, 'utf-8');
+      const {metadata, content} = parse(fileString);
+
+      return {
+        path: fileToPath(file),
+        content: content,
+        title: metadata.title,
+        date: metadata.date
+      };
+    })
+  );
+  blogDatas.sort((a, b) => b.date - a.date);
+  return blogDatas;
+}
+
+module.exports = loadBlog;