chore: prepare for docs sidebar

lib/load/docs/order.js

@@ -0,0 +1,34 @@
+// build the docs meta such as next, previous, category and sidebar
+module.exports = function createOrder(allSidebars = {}) {
+  const order = {};
+  if (!allSidebars) {
+    return order;
+  }
+  Object.keys(allSidebars).forEach(sidebar => {
+    const categories = allSidebars[sidebar];
+
+    let ids = [];
+    const categoryOrder = [];
+    Object.keys(categories).forEach(category => {
+      ids = ids.concat(categories[category]);
+      for (let i = 0; i < categories[category].length; i++) {
+        categoryOrder.push(category);
+      }
+    });
+
+    for (let i = 0; i < ids.length; i++) {
+      const id = ids[i];
+      let previous;
+      let next;
+      if (i > 0) previous = ids[i - 1];
+      if (i < ids.length - 1) next = ids[i + 1];
+      order[id] = {
+        previous,
+        next,
+        sidebar,
+        category: categoryOrder[i]
+      };
+    }
+  });
+  return order;
+};

lib/load/docs/sidebars.js

@@ -0,0 +1,34 @@
+const fs = require('fs-extra');
+const path = require('path');
+const {idx} = require('../utils');
+
+module.exports = function loadSidebars({siteDir, env}) {
+  let allSidebars = {};
+
+  // current sidebars
+  const sidebarsJSONFile = path.join(siteDir, 'sidebars.json');
+  if (fs.existsSync(sidebarsJSONFile)) {
+    allSidebars = require(sidebarsJSONFile);
+  }
+
+  // versioned sidebars
+  if (idx(env, ['versioning', 'enabled'])) {
+    const versions = idx(env, ['versioning', 'versions']);
+    versions &&
+      versions.forEach(version => {
+        const versionedSidebarsJSONFile = path.join(
+          siteDir,
+          'versioned_sidebars',
+          `version-${version}-sidebars.json`
+        );
+        if (fs.existsSync(versionedSidebarsJSONFile)) {
+          const sidebar = require(versionedSidebarsJSONFile);
+          Object.assign(allSidebars, sidebar);
+        } else {
+          const missingFile = path.relative(siteDir, versionedSidebarsJSONFile);
+          throw new Error(`Failed to load ${missingFile}. It does not exist.`);
+        }
+      });
+  }
+  return allSidebars;
+};

lib/load/utils.js

@@ -1,4 +1,6 @@
 const path = require('path');
+const fm = require('front-matter');
+const escapeStringRegexp = require('escape-string-regexp');
 const fs = require('fs-extra');
 
 const genPath = path.resolve(__dirname, '../core/generated');
@@ -40,9 +42,40 @@ function fileToComponentName(file) {
   return ext ? ext.toUpperCase() + str : str;
 }
 
+function idx(target, keyPaths) {
+  return (
+    target &&
+    (Array.isArray(keyPaths)
+      ? keyPaths.reduce((obj, key) => obj && obj[key], target)
+      : target[keyPaths])
+  );
+}
+
+function getSubFolder(file, refDir) {
+  const separator = escapeStringRegexp(path.sep);
+  const baseDir = escapeStringRegexp(path.basename(refDir));
+  const regexSubFolder = new RegExp(
+    `${baseDir}${separator}(.*?)${separator}.*`
+  );
+  const match = regexSubFolder.exec(file);
+  return match && match[1];
+}
+
+function parse(fileString) {
+  if (!fm.test(fileString)) {
+    return {metadata: null, content: fileString};
+  }
+  const {attributes: metadata, body: content} = fm(fileString);
+
+  return {metadata, content};
+}
+
 module.exports = {
   encodePath,
   generate,
   fileToPath,
-  fileToComponentName
+  fileToComponentName,
+  getSubFolder,
+  idx,
+  parse
 };