added paginate function, fixed sort bug

gulpfile.js

@@ -12,7 +12,8 @@ var gulp   = require('gulp'),
 
 gulp.task('lint', function() {
   return gulp.src(['./lib/*.js', './test/*.js', './examples/*.js'])
-    .pipe(jshint({node: true, browser: true, validthis: true, globals: {Promise: true}}))
+    .pipe(jshint({node: true, browser: true, validthis: true,
+      eqnull: true, globals: {Promise: true}}))
     .pipe(jshint.reporter(stylish))
     .pipe(jshint.reporter('fail'));
 });

lib/index.js

@@ -4,6 +4,7 @@ var helpers = require('./helpers');
 var collate = require('pouchdb-collate').collate;
 var utils = require('pouchdb-find/lib/utils');
 var localUtils = require('pouchdb-find/lib/adapters/local/utils');
+var getValue = localUtils.getValue;
 var massageSelector = localUtils.massageSelector;
 var massageSort = localUtils.massageSort;
 
@@ -39,23 +40,19 @@ function liveFind(requestDef) {
   if(requestDef.selector) {
     selector = massageSelector(requestDef.selector);
   }
-  var sort;
+  var sort, sortFn;
   if(requestDef.sort) {
     sort = massageSort(requestDef.sort);
+    sortFn = helpers.createFieldSorter(sort);
   }
-  var skip = requestDef.skip || 0;
-  var limit = requestDef.limit;
+  var skip = parseInt(requestDef.skip, 10) || 0;
+  var limit = parseInt(requestDef.limit, 10) || 0;
   var findRequest = {
     selector: selector,
     sort: sort,
     fields: fields
   };
 
-  var sortFn;
-  if(sort) {
-    sortFn = helpers.createFieldSorter(sort);
-  }
-
   var ready = db.find(findRequest)
     .then(function(results) {
       results.docs.forEach(function(doc) {
@@ -95,10 +92,10 @@ function liveFind(requestDef) {
     if(!sort) {
       return list;
     }
-    return list.sort(sortFn);
+    return sortList(list);
   };
 
-
+  emitter.paginate = paginate;
 
   function changeHandler(change) {
     ready.then(function() {
@@ -226,10 +223,19 @@ function liveFind(requestDef) {
     emitter.emit('update', { action: 'UPDATE', id: id, rev: rev, doc: doc }, list);
   }
 
+  function sortList(list) {
+    list = list.sort(sortFn);
+    if (typeof sort[0] !== 'string' &&
+      getValue(sort[0]) === 'desc') {
+      list = list.reverse();
+    }
+    return list;
+  }
+
   // Applies sort, skip, and limit to a list
   function formatList(list) {
     if(sort) {
-      list = list.sort(sortFn);
+      list = sortList(list);
     }
     if(skip || limit) {
       if(limit) {
@@ -241,6 +247,23 @@ function liveFind(requestDef) {
     return list;
   }
 
+  function paginate(options) {
+    if(!aggregate || !options || typeof options !== 'object') {
+      return;
+    }
+    if(options.skip != null) {
+      skip = parseInt(options.skip, 10) || 0;
+    }
+    if(options.limit != null) {
+      limit = parseInt(options.limit, 10) || 0;
+    }
+    if(options.sort && options.sort instanceof Array) {
+      sort = massageSort(options.sort);
+      sortFn = helpers.createFieldSorter(sort);
+    }
+    return formatList(docList);
+  }
+
   return emitter;
 
 }

test/live-find.spec.js

@@ -293,7 +293,7 @@ describe('PouchDB LiveFind', function() {
         return watcher4.fetchListUpdates(2);
       })
       .then(function(aggregates) {
-        expect(aggregates).to.deep.equal([ ['mario'], ['dk', 'mario'] ]);
+        expect(aggregates).to.deep.equal([ ['mario'], ['mario', 'dk'] ]);
         return Promise.all([
           watcher4.fetchListUpdates(2),
           db.bulkDocs(smashers2)
@@ -303,8 +303,8 @@ describe('PouchDB LiveFind', function() {
         // Testing add to list
         var aggregates = result[0];
         expect(aggregates).to.deep.equal([
-          [ 'dk', 'luigi', 'mario' ],
-          [ 'dk', 'luigi', 'mario', 'yoshi' ] ]
+          [ 'mario', 'luigi', 'dk' ],
+          [ 'yoshi', 'mario', 'luigi', 'dk' ] ]
         );
         return db.get('luigi');
       })
@@ -317,7 +317,7 @@ describe('PouchDB LiveFind', function() {
       })
       .then(function(result) {
         var aggregates = result[0];
-        expect(aggregates).to.deep.equal([ [ 'dk', 'mario', 'yoshi' ] ]);
+        expect(aggregates).to.deep.equal([ [ 'yoshi', 'mario', 'dk' ] ]);
         return db.get('yoshi');
       })
       .then(function(yoshi) {
@@ -330,7 +330,7 @@ describe('PouchDB LiveFind', function() {
       })
       .then(function(result) {
         var aggregates = result[0];
-        expect(aggregates).to.deep.equal([ [ 'yoshi', 'dk', 'mario' ] ]);
+        expect(aggregates).to.deep.equal([ [ 'mario', 'dk', 'yoshi' ] ]);
         feed4.cancel();
       });
   });
@@ -389,20 +389,50 @@ describe('PouchDB LiveFind', function() {
         expect(aggregates).to.deep.equal([
             [],
             [],
-            [ 'link' ],
-            [ 'pikachu', 'link' ],
-            [ 'puff', 'pikachu', 'link' ],
-            [ 'mario', 'puff', 'pikachu' ] ]);
+            [ 'puff' ],
+            [ 'puff', 'mario' ],
+            [ 'puff', 'mario', 'dk' ],
+            [ 'puff', 'mario', 'dk' ] ]);
       });
   });
 
   it('should have a working custom sort function', function() {
     return previous
       .then(function() {
-        var sorted = feed6.sort(smashers1).map(function(item) {
-          return item._id;
-        });
-        expect(sorted).to.deep.equal([ 'falcon', 'dk', 'mario', 'puff', 'pikachu', 'link' ]);
+        var sorted = feed6.sort(smashers1).map(mapById);
+        expect(sorted).to.deep.equal([ 'link', 'pikachu', 'puff', 'mario', 'dk', 'falcon' ]);
+      });
+  });
+
+  it('paginate should set a different sort, skip and limit', function() {
+    return previous
+      .then(function() {
+        var result1 = feed6.paginate({
+          sort: [{series: 'desc'}, {name: 'desc'}],
+          skip: 0,
+          limit: 0
+        }).map(mapById);
+        expect(result1).to.deep.equal(['link', 'pikachu', 'puff', 'mario', 'dk', 'falcon']);
+        var result2 = feed6.paginate({
+          sort: [{series: 'asc'}, {name: 'asc'}],
+          skip: 0,
+          limit: 0
+        }).map(mapById);
+        expect(result2).to.deep.equal(['falcon', 'dk', 'mario', 'puff', 'pikachu', 'link']);
+        var result3 = feed6.paginate({
+          skip: 2,
+          limit: 3
+        }).map(mapById);
+        expect(result3).to.deep.equal(['mario', 'puff', 'pikachu']);
+        // Now we'll make sure that updates keep the new pagination
+        return Promise.all( [
+          watcher6.fetchListUpdates(1),
+          db.put({ name: 'Bulbasaur', _id: 'bulb', series: 'Pokemon', debut: 1996 })
+        ]);
+      })
+      .then(function(results) {
+        var update = results[0][0];
+        expect(update).to.deep.equal(['mario', 'bulb', 'puff']);
         feed6.cancel();
       });
   });
@@ -429,4 +459,8 @@ function createDB(name) {
     return new PouchDB(name, {db: memdown});
   }
   return new PouchDB(name, {adapter: 'memory'});
+}
+
+function mapById(item) {
+  return item._id;
 }