Add splice method to linked list

bustle · Aug 10, 2015 · 6e12e70 · 6e12e70
1 parent b13be70
commit 6e12e70
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Showing 3 changed files with 58 additions and 5 deletions.
diff --git a/src/js/models/markup-section.js b/src/js/models/markup-section.js
@@ -64,11 +64,7 @@ export default class Section extends LinkedItem {
   }
 
   replaceMarker(previousMarker, newMarkers=[]) {
-    let nextMarker = previousMarker.next;
-    newMarkers.forEach(marker => {
-      this.markers.insertBefore(marker, nextMarker);
-    });
-    this.removeMarker(previousMarker);
+    this.markers.splice(previousMarker, 1, newMarkers);
   }
 
   prependMarker(marker) {

diff --git a/src/js/utils/linked-list.js b/src/js/utils/linked-list.js
@@ -129,4 +129,18 @@ export default class LinkedList {
       return (targetIndex === index);
     });
   }
+  splice(targetItem, removalCount, newItems) {
+    let item = targetItem;
+    let nextItem = item.next;
+    let count = 0;
+    while (item && count < removalCount) {
+      count++;
+      nextItem = item.next;
+      this.remove(item);
+      item = nextItem;
+    }
+    newItems.forEach((newItem) => {
+      this.insertBefore(newItem, nextItem);
+    });
+  }
 }
diff --git a/tests/unit/utils/linked-list-test.js b/tests/unit/utils/linked-list-test.js
@@ -277,3 +277,46 @@ test(`#objectAt looks up by index`, (assert) => {
   assert.equal(list.objectAt(1), itemTwo, 'itemTwo looked up');
   assert.equal(list.objectAt(2), itemThree, 'itemThree looked up');
 });
+
+test(`#splice removes a target and inserts an array of items`, (assert) => {
+  let list = new LinkedList();
+  let itemOne = new LinkedItem();
+  let itemTwo = new LinkedItem();
+  let itemThree = new LinkedItem();
+  list.append(itemOne);
+  list.append(itemThree);
+
+  list.splice(itemOne, 1, [itemTwo]);
+
+  assert.equal(list.head, itemTwo, 'itemOne is head');
+  assert.equal(list.objectAt(1), itemThree, 'itemThree is present');
+});
+
+test(`#splice remove nothing and inserts an array of nothing`, (assert) => {
+  let list = new LinkedList();
+  let itemOne = new LinkedItem();
+  let itemTwo = new LinkedItem();
+  list.append(itemOne);
+  list.append(itemTwo);
+
+  list.splice(itemTwo, 0, []);
+
+  assert.equal(list.head, itemOne, 'itemOne is head');
+  assert.equal(list.objectAt(1), itemTwo, 'itemTwo is present');
+});
+
+test(`#splice can reorganize items`, (assert) => {
+  let list = new LinkedList();
+  let itemOne = new LinkedItem();
+  let itemTwo = new LinkedItem();
+  let itemThree = new LinkedItem();
+  list.append(itemOne);
+  list.append(itemTwo);
+  list.append(itemThree);
+
+  list.splice(itemOne, 3, [itemThree, itemOne, itemTwo]);
+
+  assert.equal(list.head, itemThree, 'itemThree is head');
+  assert.equal(list.objectAt(1), itemOne, 'itemOne is present');
+  assert.equal(list.objectAt(2), itemTwo, 'itemTwo is present');
+});