feat(v2): headerlinks (#1074)

* feat(v2): headerlinks

* fix test

* nits

* remove tictactoe:

* headerIcon

* nits

* remove lang dropdown

* fix failing test

* search box

* algolia search

* use babel-eslint to resolve dynamic import

* nits

* favicon and title

* Update .eslintignore

v2/lib/load/config.js

@@ -25,6 +25,9 @@ module.exports = function loadConfig(siteDir, deleteCache = true) {
     'projectName',
     'baseUrl',
     'url',
+    'headerLinks',
+    'headerIcon',
+    'favicon',
   ];
   const optionalFields = [
     'customDocsPath',
@@ -36,6 +39,7 @@ module.exports = function loadConfig(siteDir, deleteCache = true) {
     'docsUrl',
     'customFields',
     'githubHost',
+    'algolia',
   ];
   const missingFields = requiredFields.filter(field => !config[field]);
   if (missingFields && missingFields.length > 0) {
@@ -55,6 +59,30 @@ module.exports = function loadConfig(siteDir, deleteCache = true) {
     }
   });
 
+  /* Build final headerLinks based on siteConfig */
+  const {headerLinks} = config;
+  // add language drop down to end if location not specified
+  let languages = false;
+  headerLinks.forEach(link => {
+    if (link.languages) {
+      languages = true;
+    }
+  });
+  if (!languages) {
+    headerLinks.push({languages: true});
+  }
+  let search = false;
+  headerLinks.forEach(link => {
+    // We will add search bar to end if location not specified
+    if (link.search) {
+      search = true;
+    }
+  });
+  if (!search && config.algolia) {
+    headerLinks.push({search: true});
+  }
+  config.headerLinks = headerLinks;
+
   /* 
     User's own array of custom fields, 
     e.g: if they want to include some field so they can access it later from `props.siteConfig`