Removed two +1s that cancel eachother out

Also removed if (previousBlockEndingLine) because this caused it to miss empty lines at the start of text. Added test for this case.

Author: danielsnider

src/markdown-to-draft.js

@@ -223,7 +223,7 @@ function markdownToDraft(string, options = {}) {
   var entityMap = {}; // entitymap will be returned as part of the final draftjs raw object
   var parsedData = md.parse(string, {}); // remarkable js takes markdown and makes it an array of style objects for us to easily parse
   var currentListType = null; // Because of how remarkable's data is formatted, we need to cache what kind of list we're currently dealing with
-  var previousBlockEndingLine = 1;
+  var previousBlockEndingLine = 0;
 
   // Allow user to define custom BlockTypes and Entities if they so wish
   const BlockTypes = Object.assign({}, DefaultBlockTypes, options.blockTypes || {});
@@ -277,20 +277,18 @@ function markdownToDraft(string, options = {}) {
       if (block && options.preserveNewlines) {
         // Re: previousBlockEndingLine.... omg.
         // So remarkable strips out empty newlines and doesn't make any entities to parse to restore them
-        // the only solution I could find is that there's a 2-value array on each block item called "lines" which is the start end line of the block element.
+        // the only solution I could find is that there's a 2-value array on each block item called "lines" which is the start and end line of the block element.
         // by keeping track of the PREVIOUS block element ending line and the NEXT block element starting line, we can find the difference between the new lines and insert
         // an appropriate number of extra paragraphs to re-create those newlines in draftjs.
         // This is probably my least favourite thing in this file, but not sure what could be better.
-        if (previousBlockEndingLine) {
-          var totalEmptyParagraphsToCreate = item.lines[0] - previousBlockEndingLine + 1;
-          for (var i = 0; i < totalEmptyParagraphsToCreate; i++) {
-            blocks.push(DefaultBlockTypes.paragraph_open());
-          }
+        var totalEmptyParagraphsToCreate = item.lines[0] - previousBlockEndingLine;
+        for (var i = 0; i < totalEmptyParagraphsToCreate; i++) {
+          blocks.push(DefaultBlockTypes.paragraph_open());
         }
       }
 
       if (block) {
-        previousBlockEndingLine = item.lines[1] + 1;
+        previousBlockEndingLine = item.lines[1];
         blocks.push(block);
       }
     }

test/idempotency.spec.js

@@ -28,6 +28,11 @@ describe('idempotency', function () {
 
     expect(markdownFromDraft).toEqual(markdownString);
 
+    markdownString = '\n\na';
+    draftJSObject = markdownToDraft(markdownString, {preserveNewlines: true});
+    markdownFromDraft = draftToMarkdown(draftJSObject, {preserveNewlines: true});
+    expect(markdownFromDraft).toEqual(markdownString);
+
   });
 
   it('renders new lines text correctly with styled blocks', function () {