Add tests for the linked list struct

test/spec/ol/structs/linkedlist.test.js

@@ -0,0 +1,267 @@
+goog.provide('ol.test.structs.LinkedList');
+
+goog.require('ol.structs.LinkedList');
+
+describe('ol.structs.LinkedList', function() {
+  var ll;
+  var item = {};
+  var item2 = {};
+  beforeEach(function() {
+    ll = new ol.structs.LinkedList();
+  });
+
+  it('defaults to circular', function() {
+    expect(ll.circular_).to.be(true);
+  });
+
+  it('creates an empty list', function() {
+    expect(ll.length_).to.be(0);
+    expect(ll.first_).to.be(undefined);
+    expect(ll.last_).to.be(undefined);
+    expect(ll.head_).to.be(undefined);
+  });
+
+  describe('#insertItem', function() {
+    beforeEach(function() {
+      ll.insertItem(item);
+    });
+
+    it('inserts an item into the list', function() {
+      expect(ll.length_).to.be(1);
+    });
+
+    it('sets the cursor to the inserted item', function() {
+      expect(ll.head_.data).to.be(item);
+    });
+
+    it('links the previous item to the new one', function() {
+      ll.insertItem(item2);
+      expect(ll.head_.prev.data).to.be(item);
+      expect(ll.head_.prev.next.data).to.be(item2);
+    });
+  });
+
+  describe('#removeItem', function() {
+    var item3 = {};
+    beforeEach(function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.insertItem(item3);
+    });
+
+    it('removes the current item', function() {
+      ll.removeItem();
+      expect(ll.length_).to.be(2);
+      expect(ll.head_.data).not.to.be(item3);
+    });
+
+    it('sets the cursor to the next item if possible', function() {
+      ll.removeItem();
+      expect(ll.head_.data).to.be(item);
+    });
+
+    it('otherwise sets the cursor to the prevous item', function() {
+      ll = new ol.structs.LinkedList(false);
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.insertItem(item3);
+      ll.removeItem();
+      expect(ll.head_.data).to.be(item2);
+    });
+
+    it('empties a list with only one item', function() {
+      ll = new ol.structs.LinkedList();
+      ll.insertItem(item);
+      ll.removeItem();
+      expect(ll.length_).to.be(0);
+      expect(ll.head_).to.be(undefined);
+      expect(ll.first_).to.be(undefined);
+      expect(ll.last_).to.be(undefined);
+    });
+  });
+
+  describe('#firstItem', function() {
+    it('sets the cursor to the first item and returns its data', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      var i = ll.firstItem();
+      expect(i).to.be(item);
+      expect(ll.head_.data).to.be(item);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.firstItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#lastItem', function() {
+    it('sets the cursor to the last item and returns its data', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.firstItem();
+      var i = ll.lastItem();
+      expect(i).to.be(item2);
+      expect(ll.head_.data).to.be(item2);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.lastItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#nextItem', function() {
+    it('sets the cursor to the next item and returns its data', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.firstItem();
+      var i = ll.nextItem();
+      expect(i).to.be(item2);
+      expect(ll.head_.data).to.be(item2);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.nextItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#prevItem', function() {
+    it('sets the cursor to the previous item and returns its data', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      var i = ll.prevItem();
+      expect(i).to.be(item);
+      expect(ll.head_.data).to.be(item);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.prevItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#getNextItem', function() {
+    it('returns the data of the next item without stepping the cursor', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.firstItem();
+      var i = ll.getNextItem();
+      expect(i).to.be(item2);
+      expect(ll.head_.data).to.be(item);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.getNextItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#getPrevItem', function() {
+    it('returns the data of the previous item without stepping the cursor', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      var i = ll.getPrevItem();
+      expect(i).to.be(item);
+      expect(ll.head_.data).to.be(item2);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.getPrevItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#getCurrItem', function() {
+    it('returns the data of the current item', function() {
+      var item3 = {};
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      ll.insertItem(item3);
+      ll.prevItem();
+      var i = ll.getCurrItem();
+      expect(i).to.be(item2);
+      expect(ll.head_.data).to.be(item2);
+    });
+
+    it('returns undefined on empty list', function() {
+      var i = ll.getCurrItem();
+      expect(i).to.be(undefined);
+    });
+  });
+
+  describe('#getLength', function() {
+    it('returns the length of the list', function() {
+      ll.insertItem(item);
+      ll.insertItem(item2);
+      var l = ll.getLength();
+      expect(l).to.be(2);
+    });
+  });
+
+  describe('#concat', function() {
+    var ll2, item3;
+    beforeEach(function() {
+      item3 = {};
+      ll2 = new ol.structs.LinkedList();
+      ll2.insertItem(item);
+      ll2.insertItem(item2);
+      ll2.insertItem(item3);
+    });
+
+    it('concatenates a second list with the current one', function() {
+      var item4 = {};
+      var item5 = {};
+      var item6 = {};
+      ll.insertItem(item4);
+      ll.insertItem(item5);
+      ll.insertItem(item6);
+      ll.prevItem();
+      ll.concat(ll2);
+      expect(ll.length_).to.be(6);
+      expect(ll.head_.data).to.be(item5);
+      expect(ll.head_.next.data).to.be(item);
+      expect(ll.head_.next.next.next.next.data).to.be(item6);
+    });
+
+    it('receives the second list if the current one is empty', function() {
+      ll.concat(ll2);
+      expect(ll.length_).to.be(3);
+      expect(ll.first_.data).to.be(item);
+      expect(ll.last_.data).to.be(item3);
+      expect(ll.head_.data).to.be(item3);
+    });
+
+    it('destroys the second list', function() {
+      ll.concat(ll2);
+      expect(ll2.length_).to.be(0);
+      expect(ll2.first_).to.be(undefined);
+      expect(ll2.last_).to.be(undefined);
+      expect(ll2.head_).to.be(undefined);
+    });
+  });
+
+  describe('when circular', function() {
+    beforeEach(function() {
+      ll = new ol.structs.LinkedList();
+      ll.insertItem(item);
+    });
+
+    describe('#insertItem', function() {
+      it('initializes the list in a circular way', function() {
+        expect(ll.head_.prev.data).to.be(item);
+        expect(ll.head_.next.data).to.be(item);
+      });
+    });
+
+    describe('#setFirstItem', function() {
+      it('resets the first item to the current one', function() {
+        ll.insertItem(item2);
+        ll.setFirstItem();
+        expect(ll.first_.data).to.be(item2);
+        expect(ll.last_.data).to.be(item);
+      });
+    });
+  });
+});