Add versioning functionality

lib/server/versionFallback.js

@@ -0,0 +1,278 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+const CWD = process.cwd();
+const semver = require("semver");
+const glob = require("glob");
+const fs = require("fs");
+const path = require("path");
+const diff = require("diff");
+const assert = require("assert");
+const siteConfig = require(CWD + "/siteConfig.js");
+
+const ENABLE_TRANSLATION = fs.existsSync(CWD + "/languages.js");
+let languages;
+if (fs.existsSync(CWD + "/languages.js")) {
+  languages = require(CWD + "/languages.js");
+} else {
+  languages = [
+    {
+      enabled: true,
+      name: "English",
+      tag: "en"
+    }
+  ];
+}
+
+/*****************************************************************/
+
+// included to prevent cyclical dependency with readMetadata.js
+
+function splitHeader(content) {
+  const lines = content.split("\n");
+  let i = 1;
+  for (; i < lines.length - 1; ++i) {
+    if (lines[i] === "---") {
+      break;
+    }
+  }
+  return {
+    header: lines.slice(1, i + 1).join("\n"),
+    content: lines.slice(i + 1).join("\n")
+  };
+}
+
+// Extract markdown metadata header
+function extractMetadata(content) {
+  const metadata = {};
+  const both = splitHeader(content);
+  const lines = both.header.split("\n");
+  for (let i = 0; i < lines.length - 1; ++i) {
+    const keyvalue = lines[i].split(":");
+    const key = keyvalue[0].trim();
+    let value = keyvalue.slice(1).join(":").trim();
+    // Handle the case where you have "Community #10"
+    try {
+      value = JSON.parse(value);
+    } catch (e) {}
+    metadata[key] = value;
+  }
+  return { metadata, rawContent: both.content };
+}
+
+/*****************************************************************/
+
+/* preprocessing */
+const versions = [];
+const versionFolder = ENABLE_TRANSLATION
+  ? CWD + "/versioned_docs/en/"
+  : CWD + "/versioned_docs/";
+let files = glob.sync(versionFolder + "*");
+files.forEach(file => {
+  if (!fs.lstatSync(file).isDirectory()) {
+    return;
+  }
+  const version = file.split("version-")[1];
+  versions.push(version);
+});
+versions.sort(semver.rcompare);
+
+const available = {};
+const versionFiles = {};
+files = glob.sync(versionFolder + "**");
+files.forEach(file => {
+  const ext = path.extname(file);
+  if (ext !== ".md" && ext !== ".markdown") {
+    return;
+  }
+  const res = extractMetadata(fs.readFileSync(file, "utf8"));
+  const metadata = res.metadata;
+
+  if (!(metadata.original_id in available)) {
+    available[metadata.original_id] = new Set();
+  }
+  const version = metadata.id.split("-")[1];
+  available[metadata.original_id].add(version);
+
+  if (!(version in versionFiles)) {
+    versionFiles[version] = {};
+  }
+  versionFiles[version][metadata.original_id] = file;
+});
+
+function docVersion(id, req_version) {
+  for (let i = 0; i < versions.length; i++) {
+    if (semver.gt(versions[i], req_version)) {
+      continue;
+    }
+    if (!available[id]) {
+      return null;
+    }
+    if (available[id].has(versions[i])) {
+      return versions[i];
+    }
+  }
+  return null;
+}
+
+function diffLatestDoc(file, id) {
+  if (versions.length === 0) {
+    return true;
+  }
+
+  const latest = versions[0];
+
+  const version = docVersion(id, latest);
+  if (!version) {
+    return true;
+  }
+  const latestFile = versionFiles[version][id];
+
+  if (!latestFile || !fs.existsSync(latestFile)) {
+    return true;
+  }
+
+  const diffs = diff.diffChars(
+    extractMetadata(fs.readFileSync(latestFile, "utf8")).rawContent,
+    extractMetadata(fs.readFileSync(file, "utf8")).rawContent
+  );
+  diffs.forEach(part => {
+    if (part.added || part.removed) {
+      return true;
+    }
+  });
+  return false;
+}
+
+function processVersionMetadata(file, version, useVersion, language) {
+  const metadata = extractMetadata(fs.readFileSync(file, "utf8")).metadata;
+  metadata.source = "version-" + useVersion + "/" + path.basename(file);
+  if (!ENABLE_TRANSLATION && !siteConfig.useEnglishUrl) {
+    metadata.permalink =
+      "docs/" + version + "/" + metadata.original_id + ".html";
+  } else {
+    metadata.permalink =
+      "docs/" + language + "/" + version + "/" + metadata.original_id + ".html";
+  }
+  metadata.id = metadata.id.replace(
+    "version-" + useVersion + "-",
+    "version-" + version + "-"
+  );
+  metadata.localized_id = metadata.id;
+  metadata.id = language + "-" + metadata.id;
+  metadata.language = language;
+  metadata.version = version;
+
+  return metadata;
+}
+
+function docData() {
+  const files = glob.sync(CWD + "/versioned_docs/**");
+
+  allIds = new Set();
+  Object.keys(versionFiles).forEach(version => {
+    Object.keys(versionFiles[version]).forEach(id => {
+      allIds.add(id);
+    });
+  });
+
+  const metadatas = [];
+
+  languages.filter(language => language.enabled).forEach(language => {
+    versions.forEach(version => {
+      allIds.forEach(id => {
+        const useVersion = docVersion(id, version);
+        if (!useVersion) {
+          return;
+        }
+        const file = versionFiles[useVersion][id];
+
+        metadatas.push(
+          processVersionMetadata(file, version, useVersion, language.tag)
+        );
+      });
+    });
+  });
+
+  return metadatas;
+}
+
+function sidebarVersion(req_version) {
+  for (let i = 0; i < versions.length; i++) {
+    if (semver.gt(versions[i], req_version)) {
+      continue;
+    }
+    if (
+      fs.existsSync(
+        CWD + "/versioned_sidebars/version-" + versions[i] + "-sidebar.json"
+      )
+    ) {
+      return versions[i];
+    }
+  }
+  return null;
+}
+
+function diffLatestSidebar() {
+  if (versions.length === 0) {
+    return true;
+  }
+  const latest = versions[0];
+
+  const version = sidebarVersion(latest);
+  const latestSidebar =
+    CWD + "/versioned_sidebars/version-" + version + "-sidebar.json";
+  if (!fs.existsSync(latestSidebar)) {
+    return true;
+  }
+  const currentSidebar = CWD + "/sidebar.json";
+  if (!fs.existsSync(currentSidebar)) {
+    // TO DO: error message
+  }
+
+  // compare for equality between latest version sidebar with version prefixes
+  // stripped and current sidebar
+  return (
+    JSON.stringify(JSON.parse(fs.readFileSync(latestSidebar, "utf8"))).replace(
+      new RegExp("version-" + version + "-", "g"),
+      ""
+    ) !== JSON.stringify(JSON.parse(fs.readFileSync(currentSidebar, "utf8")))
+  );
+}
+
+function sidebarData() {
+  const allSidebars = {};
+
+  for (let i = 0; i < versions.length; i++) {
+    const version = sidebarVersion(versions[i]);
+    const sidebar = JSON.parse(
+      fs
+        .readFileSync(
+          CWD + "/versioned_sidebars/version-" + version + "-sidebar.json",
+          "utf8"
+        )
+        .replace(
+          new RegExp("version-" + version + "-", "g"),
+          "version-" + versions[i] + "-"
+        )
+    );
+    Object.assign(allSidebars, sidebar);
+  }
+  return allSidebars;
+}
+
+module.exports = {
+  docVersion,
+  diffLatestDoc,
+  processVersionMetadata,
+  docData,
+  sidebarVersion,
+  diffLatestSidebar,
+  sidebarData
+};