dev: update .eslintrc.yml & fix no-use-before-define error

.eslintrc.yml

@@ -3,8 +3,19 @@ env:
   es6: true
 extends:
   - 'eslint:recommended'
+  - 'plugin:node/recommended'
+  - 'plugin:import/recommended'
   - 'prettier'
 parserOptions:
-  ecmaVersion: 2017
+  ecmaVersion: 2020
 rules:
   no-console: error
+  prefer-const: error
+  no-var: error
+  no-use-before-define: error
+  no-await-in-loop: error
+  node/exports-style: [0, error]
+  import/first: error
+  import/no-anonymous-default-export: error
+  import/no-unassigned-import: error
+  import/no-internal-modules: error

lib/index.js

@@ -99,6 +99,22 @@ const relink = (data, moved) => {
   data.contents = Buffer.from(content)
 }
 
+/**
+ * Check whether a file is an HTML file.
+ *
+ * @param {string} str The path
+ * @return {boolean}
+ */
+const html = (str) => path.extname(str) === '.html'
+
+/**
+ * Return a formatter for a given moment.js format `string`.
+ *
+ * @param {string} string
+ * @return {Function}
+ */
+const format = (string) => (date) => moment(date).utc().format(string)
+
 /**
  * Normalize an options argument.
  *
@@ -117,14 +133,6 @@ const normalizeOptions = (options) => {
   return options
 }
 
-/**
- * Return a formatter for a given moment.js format `string`.
- *
- * @param {string} string
- * @return {Function}
- */
-const format = (string) => (date) => moment(date).utc().format(string)
-
 /**
  * Get a list of sibling and children files for a given `file` in `files`.
  *
@@ -237,14 +245,6 @@ const replace = (pattern, data, options) => {
   return transformed
 }
 
-/**
- * Check whether a file is an HTML file.
- *
- * @param {string} str The path
- * @return {boolean}
- */
-const html = (str) => path.extname(str) === '.html'
-
 /**
  * Metalsmith plugin that renames files so that they're permalinked properly
  * for a static site, aka that `about.html` becomes `about/index.html`.