Add collation and fix tests

.vscode/launch.json

@@ -0,0 +1,26 @@
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Test",
+      "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
+      "args": [
+        "-u",
+        "tdd",
+        "--timeout",
+        "999999",
+        "--colors",
+        "${workspaceFolder}/tests/*"
+      ],
+      "internalConsoleOptions": "openOnSessionStart",
+      "env": {
+      },
+      "outputCapture": "std"
+    },
+  ]
+}

README.md

@@ -53,7 +53,9 @@ Promise fulfilled with object having properties:
 * `total` {Number} - Total number of documents in collection that match a query
 * `limit` {Number} - Limit that was used
 * `[page]` {Number} - Only if specified or default `page`/`offset` values were used 
-* `[pages]` {Number} - Only if `page` specified or default `page`/`offset` values were used 
+* `[pages]` {Number} - Only if `page` specified or default `page`/`offset` values were used
+* `[prev]` {Number} - Only if there is a previous page to go to.
+* `[next]` {Number} - Only if there is a next page to go to.
 * `[offset]` {Number} - Only if specified or default `page`/`offset` values were used
 
 ### Examples

index.js

@@ -6,6 +6,7 @@
  * @param {Object} [options={}]
  * @param {Object|String} [options.select]
  * @param {Object|String} [options.sort]
+ * @param {Object} [options.collation]
  * @param {Array|Object|String} [options.populate]
  * @param {Boolean} [options.lean=false]
  * @param {Boolean} [options.leanWithId=true]
@@ -22,74 +23,88 @@ function paginate(query, options, callback) {
   let select = options.select;
   let sort = options.sort;
   let populate = options.populate;
+  let collation = options.collation || {};
   let lean = options.lean || false;
-  let leanWithId = options.leanWithId ? options.leanWithId : true;
-  let limit = options.limit ? options.limit : 10;
-  let page, offset, skip, promises;
-  if (options.offset) {
+  let leanWithId = options.hasOwnProperty('leanWithId') ? options.leanWithId : true;
+  let limit = options.hasOwnProperty('limit') ? options.limit : 10;
+  let page, offset, skip, promises = [];
+  if (options.hasOwnProperty('offset')) {
     offset = options.offset;
     skip = offset;
-  } else if (options.page) {
+  } else if (options.hasOwnProperty('page')) {
     page = options.page;
     skip = (page - 1) * limit;
   } else {
     page = 1;
     offset = 0;
     skip = offset;
   }
-  if (limit) {
+
+  promises.push(this.count(query).exec());
+
+  if (limit > 0) {
     let docsQuery = this.find(query)
       .select(select)
       .sort(sort)
       .skip(skip)
       .limit(limit)
-      .lean(lean);
+      .lean(lean)
+      .collation(collation);
     if (populate) {
       [].concat(populate).forEach((item) => {
         docsQuery.populate(item);
       });
     }
-    promises = {
-      docs: docsQuery.exec(),
-      count: this.count(query).exec()
-    };
+
+    let docPromise = docsQuery.exec();
+
     if (lean && leanWithId) {
-      promises.docs = promises.docs.then((docs) => {
+      docPromise = docPromise.then((docs) => {
         docs.forEach((doc) => {
           doc.id = String(doc._id);
         });
         return docs;
       });
     }
+
+    promises.push(docPromise);
   }
-  promises = Object.keys(promises).map((x) => promises[x]);
+
   return Promise.all(promises).then((data) => {
     let result = {
-      docs: data.docs,
-      total: data.count,
+      total: data[0],
+      docs: data[1] || [],
       limit: limit
     };
     if (offset !== undefined) {
       result.offset = offset;
     }
     if (page !== undefined) {
       result.page = page;
-      result.pages = Math.ceil(data.count / limit) || 1;
+      result.pages = Math.ceil(result.total / limit) || 1;
+      let prev = page - 1;
+      let next = page + 1;
+
+      if (prev > 0) {
+        result.prev = prev;
+      }
+
+      if (next <= result.pages) {
+        result.next = next;
+      }
     }
     if (typeof callback === 'function') {
       return callback(null, result);
     }
-    let promise = new Promise();
-    promise.resolve(result);
-    return promise;
+    return result;
   });
 }
 
 /**
  * @param {Schema} schema
  */
 
-module.exports = function(schema) {
+module.exports = function (schema) {
   schema.statics.paginate = paginate;
 };