Merge pull request #61 from facebookexperimental/error-messages

Add better error messages for most common cases

lib/server/readCategories.js

@@ -56,7 +56,9 @@ function readCategories(sidebar) {
       if (metadata.next) {
         if (!articles[metadata.next]) {
           throw new Error(
-            "`next: " + metadata.next + "` in " + metadata.id + " doesn't exist"
+            metadata.version
+              ? `Improper sidebars file for version ${metadata.version}. Make sure that all documents with ids specified in this version's sidebar file exist and that no ids are repeated.`
+              : `Improper sidebars.json file. Make sure that documents with the ids specified in sidebars.json exist and that no ids are repeated.`
           );
         }
         previous[articles[metadata.next].id] = metadata.id;

lib/server/readMetadata.js

@@ -32,7 +32,12 @@ if (fs.existsSync(CWD + "/languages.js")) {
 }
 
 function readSidebar() {
-  let allSidebars = require(CWD + "/sidebars.json");
+  let allSidebars;
+  if (fs.existsSync(CWD + "/sidebars.json")) {
+    allSidebars = require(CWD + "/sidebars.json");
+  } else {
+    allSidebars = {};
+  }
   Object.assign(allSidebars, versionFallback.sidebarData());
 
   const order = {};
@@ -155,7 +160,7 @@ function processMetadata(file) {
       metadata.previous = language + "-" + order[id].previous;
     }
   }
-  
+
   return { metadata, rawContent: rawContent };
 }
 

lib/server/server.js

@@ -157,6 +157,10 @@ function execute(port) {
     });
 
     const metadata = Metadata[links[url]];
+    if (!metadata) {
+      next();
+      return;
+    }
     const language = metadata.language;
 
     let file;
@@ -438,7 +442,6 @@ function execute(port) {
     res.send(cssContent);
   });
 
-  /* serve static content first from user folder then from docusaurus */
   app.use(
     siteConfig.baseUrl + "docs/assets/",
     express.static(CWD + "/../docs/assets")

lib/server/versionFallback.js

@@ -20,7 +20,7 @@ const ENABLE_TRANSLATION = fs.existsSync(CWD + "/languages.js");
 
 let versions;
 if (fs.existsSync(CWD + "/versions.json")) {
- versions = require(CWD + "/versions.json");
+  versions = require(CWD + "/versions.json");
 } else {
   versions = [];
 }
@@ -124,7 +124,9 @@ function docVersion(id, req_version) {
       return versions[i];
     }
   }
-  return null;
+  throw new Error(
+    `No document available to use for version ${req_version} of document with id ${id}. Verify that all version files are correct.`
+  );
 }
 
 // returns whether a given file has content that differ from the
@@ -226,7 +228,7 @@ function docData() {
 // return the version of the sidebar to use given a requested version
 function sidebarVersion(req_version) {
   // iterate through versions until a version less than or equal to the requested
-  // is found, then check if that verison has an available file to use
+  // is found, then check if that version has an available file to use
   let requestedFound = false;
   for (let i = 0; i < versions.length; i++) {
     if (versions[i] === req_version) {
@@ -243,7 +245,9 @@ function sidebarVersion(req_version) {
       return versions[i];
     }
   }
-  return null;
+  throw new Error(
+    `No sidebar file available to use for version ${req_version}. Verify that all version files are correct.`
+  );
 }
 
 // return whether or not the current sidebars.json file differs from the