1 files changed, 66 insertions, 0 deletions
diff --git a/app/assets/javascripts/diff.js b/app/assets/javascripts/diff.js
new file mode 100644
index 00000000000..3dd7ceba92f
--- /dev/null
+++ b/app/assets/javascripts/diff.js
@@ -0,0 +1,66 @@
+(function() {
+  this.Diff = (function() {
+    var UNFOLD_COUNT;
+
+    UNFOLD_COUNT = 20;
+
+    function Diff() {
+      $('.files .diff-file').singleFileDiff();
+      this.filesCommentButton = $('.files .diff-file').filesCommentButton();
+      $(document).off('click', '.js-unfold');
+      $(document).on('click', '.js-unfold', (function(_this) {
+        return function(event) {
+          var line_number, link, file, offset, old_line, params, prev_new_line, prev_old_line, ref, ref1, since, target, to, unfold, unfoldBottom;
+          target = $(event.target);
+          unfoldBottom = target.hasClass('js-unfold-bottom');
+          unfold = true;
+          ref = _this.lineNumbers(target.parent()), old_line = ref[0], line_number = ref[1];
+          offset = line_number - old_line;
+          if (unfoldBottom) {
+            line_number += 1;
+            since = line_number;
+            to = line_number + UNFOLD_COUNT;
+          } else {
+            ref1 = _this.lineNumbers(target.parent().prev()), prev_old_line = ref1[0], prev_new_line = ref1[1];
+            line_number -= 1;
+            to = line_number;
+            if (line_number - UNFOLD_COUNT > prev_new_line + 1) {
+              since = line_number - UNFOLD_COUNT;
+            } else {
+              since = prev_new_line + 1;
+              unfold = false;
+            }
+          }
+          file = target.parents('.diff-file');
+          link = file.data('blob-diff-path');
+          params = {
+            since: since,
+            to: to,
+            bottom: unfoldBottom,
+            offset: offset,
+            unfold: unfold,
+            indent: 1,
+            view: file.data('view')
+          };
+          return $.get(link, params, function(response) {
+            return target.parent().replaceWith(response);
+          });
+        };
+      })(this));
+    }
+
+    Diff.prototype.lineNumbers = function(line) {
+      if (!line.children().length) {
+        return [0, 0];
+      }
+
+      return line.find('.diff-line-num').map(function() {
+        return parseInt($(this).data('linenumber'));
+      });
+    };
+
+    return Diff;
+
+  })();
+
+}).call(this);