Refactor routing in App component to enhance navigation and improve error handling by integrating dynamic routes and updating the NotFound route.

node_modules/gray-matter/lib/excerpt.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const defaults = require('./defaults');
+
+module.exports = function(file, options) {
+  const opts = defaults(options);
+
+  if (file.data == null) {
+    file.data = {};
+  }
+
+  if (typeof opts.excerpt === 'function') {
+    return opts.excerpt(file, opts);
+  }
+
+  const sep = file.data.excerpt_separator || opts.excerpt_separator;
+  if (sep == null && (opts.excerpt === false || opts.excerpt == null)) {
+    return file;
+  }
+
+  const delimiter = typeof opts.excerpt === 'string'
+    ? opts.excerpt
+    : (sep || opts.delimiters[0]);
+
+  // if enabled, get the excerpt defined after front-matter
+  const idx = file.content.indexOf(delimiter);
+  if (idx !== -1) {
+    file.excerpt = file.content.slice(0, idx);
+  }
+
+  return file;
+};