Modifier moveArticleAfter

3 files changed, 141 insertions, 0 deletions

diff --git a/lib/modifiers/summary/__tests__/moveArticleAfter.js b/lib/modifiers/summary/__tests__/moveArticleAfter.js
new file mode 100644
index 0000000..c380575
--- /dev/null
+++ b/lib/modifiers/summary/__tests__/moveArticleAfter.js
@@ -0,0 +1,82 @@
+var Immutable = require('immutable');
+var Summary = require('../../../models/summary');
+var File = require('../../../models/file');
+
+describe('moveArticleAfter', function() {
+    var moveArticleAfter = require('../moveArticleAfter');
+    var summary = Summary.createFromParts(File(), [
+        {
+            articles: [
+                {
+                    title: '1.1',
+                    path: '1.1'
+                },
+                {
+                    title: '1.2',
+                    path: '1.2'
+                }
+            ]
+        },
+        {
+            title: 'Part I',
+            articles: [
+                {
+                    title: '2.1',
+                    path: '2.1',
+                    articles: [
+                        {
+                            title: '2.1.1',
+                            path: '2.1.1'
+                        },
+                        {
+                            title: '2.1.2',
+                            path: '2.1.2'
+                        }
+                    ]
+                },
+                {
+                    title: '2.2',
+                    path: '2.2'
+                }
+            ]
+        }
+    ]);
+
+    it('moving right after itself should be invariant', function() {
+        var newSummary = moveArticleAfter(summary, '2.1', '2.1');
+
+        expect(Immutable.is(summary, newSummary)).toBe(true);
+    });
+
+    it('moving after previous one should be invariant too', function() {
+        var newSummary = moveArticleAfter(summary, '2.1', '2.0');
+
+        expect(Immutable.is(summary, newSummary)).toBe(true);
+    });
+
+    it('should move an article after a previous level', function() {
+        var newSummary = moveArticleAfter(summary, '2.2', '2.0');
+        var moved = newSummary.getByLevel('2.1');
+
+        expect(moved.getTitle()).toBe('2.2');
+        expect(newSummary.getByLevel('2.2').getTitle()).toBe('2.1');
+    });
+
+    it('should move an article after a previous and less deep level', function() {
+        var newSummary = moveArticleAfter(summary, '2.1.1', '2.0');
+        var moved = newSummary.getByLevel('2.1');
+
+        expect(moved.getTitle()).toBe('2.1.1');
+        expect(newSummary.getByLevel('2.2.1').getTitle()).toBe('2.1.2');
+        expect(newSummary.getByLevel('2.2').getTitle()).toBe('2.1');
+    });
+
+    it('should move an article after a next level', function() {
+        var newSummary = moveArticleAfter(summary, '2.1', '2.2');
+        var moved = newSummary.getByLevel('2.2');
+
+        expect(moved.getTitle()).toBe('2.1');
+        expect(newSummary.getByLevel('2.1').getTitle()).toBe('2.2');
+    });
+
+});
diff --git a/lib/modifiers/summary/index.js b/lib/modifiers/summary/index.js
index 2b84f66..3ee0367 100644
--- a/lib/modifiers/summary/index.js
+++ b/lib/modifiers/summary/index.js
@@ -1,6 +1,7 @@
 module.exports = {
     insertArticle:      require('./insertArticle'),
     moveArticle:        require('./moveArticle'),
+    moveArticleAfter:   require('./moveArticleAfter'),
     removeArticle:      require('./removeArticle'),
     unshiftArticle:     require('./unshiftArticle'),
     editArticleTitle:   require('./editArticleTitle'),
diff --git a/lib/modifiers/summary/moveArticleAfter.js b/lib/modifiers/summary/moveArticleAfter.js
new file mode 100644
index 0000000..e03eae9
--- /dev/null
+++ b/lib/modifiers/summary/moveArticleAfter.js
@@ -0,0 +1,58 @@
+var is = require('is');
+var removeArticle = require('./removeArticle');
+var insertArticle = require('./insertArticle');
+
+/**
+    Returns a new summary, with the an article moved after another article.
+
+    @param {Summary} summary
+    @param {String|SummaryArticle} origin
+    @param {String|SummaryArticle} afterTarget
+    @return {Summary}
+*/
+function moveArticleAfter(summary, origin, afterTarget) {
+    // Coerce to level
+    var originLevel = is.string(origin)? origin : origin.getLevel();
+    var afterTargetLevel = is.string(afterTarget)? afterTarget : afterTarget.getLevel();
+    var article = summary.getByLevel(originLevel);
+
+    var targetLevel = increment(afterTargetLevel);
+
+    if (targetLevel < origin) {
+        // Remove first
+        var removed = removeArticle(summary, originLevel);
+        // Insert then
+        return insertArticle(removed, article, targetLevel);
+    } else {
+        // Insert right after first
+        var inserted = insertArticle(summary, article, targetLevel);
+        // Remove old one
+        return removeArticle(inserted, originLevel);
+    }
+}
+
+/**
+    @param {String}
+    @return {Array<Number>}
+ */
+function levelToArray(l) {
+    return l.split('.').map(function (char) {
+        return parseInt(char, 10);
+    });
+}
+
+/**
+    @param {Array<Number>}
+    @return {String}
+ */
+function arrayToLevel(a) {
+    return a.join('.');
+}
+
+function increment(level) {
+    level = levelToArray(level);
+    level[level.length - 1]++;
+    return arrayToLevel(level);
+}
+
+module.exports = moveArticleAfter;