validation

Author: mightyaleksey

src/validate.js

@@ -1 +1,31 @@
-export default function validate() {}
+import forEach from 'lodash.foreach';
+import { is } from './utility';
+import { format } from 'util';
+
+const rules = {
+  // hook
+  extensions:         'array',
+  preprocessCss:      'function',
+  processCss:         'function',
+  to:                 'string',
+  // plugins
+  append:             'array',
+  prepend:            'array',
+  use:                'array',
+  createImportedName: 'function',
+  generateScopedName: 'function|string',
+  mode:               'string',
+  rootDir:            'string',
+};
+
+export default function validate(options = {}) {
+  forEach(rules, (types, rule) => {
+    if (!options[rule]) {
+      return;
+    }
+
+    if (!types.split('|').some(type => is(type, options[rule]))) {
+      throw new Error(format('should specify %s for the %s', types, rule));
+    };
+  });
+}