From 7abdc24c7e3bd07f2f22bee521750b353402f4e9 Mon Sep 17 00:00:00 2001
From: Jan Christophersen <jan@ruken.pw>
Date: Wed, 22 Feb 2017 20:58:24 +0100
Subject: [PATCH] Only add a newline in Markdown Editor if the current line is
 not empty

---
 .../javascripts/lib/utils/text_utility.js     | 18 ++++--
 .../unreleased/27978-improve-task-list-ux.yml |  4 ++
 .../lib/utils/text_utility_spec.js.es6        | 60 +++++++++++++++++++
 3 files changed, 78 insertions(+), 4 deletions(-)
 create mode 100644 changelogs/unreleased/27978-improve-task-list-ux.yml

diff --git a/app/assets/javascripts/lib/utils/text_utility.js b/app/assets/javascripts/lib/utils/text_utility.js
index 579d322e3fb..2e5f8a09fc1 100644
--- a/app/assets/javascripts/lib/utils/text_utility.js
+++ b/app/assets/javascripts/lib/utils/text_utility.js
@@ -65,9 +65,10 @@ require('vendor/latinise');
       }
     };
     gl.text.insertText = function(textArea, text, tag, blockTag, selected, wrap) {
-      var insertText, inserted, selectedSplit, startChar, removedLastNewLine, removedFirstNewLine;
+      var insertText, inserted, selectedSplit, startChar, removedLastNewLine, removedFirstNewLine, currentLineEmpty, lastNewLine;
       removedLastNewLine = false;
       removedFirstNewLine = false;
+      currentLineEmpty = false;
 
       // Remove the first newline
       if (selected.indexOf('\n') === 0) {
@@ -82,7 +83,17 @@ require('vendor/latinise');
       }
 
       selectedSplit = selected.split('\n');
-      startChar = !wrap && textArea.selectionStart > 0 ? '\n' : '';
+
+      if (!wrap) {
+        lastNewLine = textArea.value.substr(0, textArea.selectionStart).lastIndexOf('\n');
+
+        // Check whether the current line is empty or consists only of spaces(=handle as empty)
+        if (/^\s*$/.test(textArea.value.substring(lastNewLine, textArea.selectionStart))) {
+          currentLineEmpty = true;
+        }
+      }
+
+      startChar = !wrap && !currentLineEmpty && textArea.selectionStart > 0 ? '\n' : '';
 
       if (selectedSplit.length > 1 && (!wrap || (blockTag != null))) {
         if (blockTag != null) {
@@ -142,9 +153,8 @@ require('vendor/latinise');
       }
     };
     gl.text.updateText = function(textArea, tag, blockTag, wrap) {
-      var $textArea, oldVal, selected, text;
+      var $textArea, selected, text;
       $textArea = $(textArea);
-      oldVal = $textArea.val();
       textArea = $textArea.get(0);
       text = $textArea.val();
       selected = this.selectedText(text, textArea);
diff --git a/changelogs/unreleased/27978-improve-task-list-ux.yml b/changelogs/unreleased/27978-improve-task-list-ux.yml
new file mode 100644
index 00000000000..a6bd99da82e
--- /dev/null
+++ b/changelogs/unreleased/27978-improve-task-list-ux.yml
@@ -0,0 +1,4 @@
+---
+title: Only add a newline in the Markdown Editor if the current line is not empty
+merge_request: 9455
+author: Jan Christophersen
diff --git a/spec/javascripts/lib/utils/text_utility_spec.js.es6 b/spec/javascripts/lib/utils/text_utility_spec.js.es6
index 06b69b8ac17..4200e943121 100644
--- a/spec/javascripts/lib/utils/text_utility_spec.js.es6
+++ b/spec/javascripts/lib/utils/text_utility_spec.js.es6
@@ -46,5 +46,65 @@ require('~/lib/utils/text_utility');
         expect(gl.text.highCountTrim(45)).toBe(45);
       });
     });
+
+    describe('gl.text.insertText', () => {
+      let textArea;
+
+      beforeAll(() => {
+        textArea = document.createElement('textarea');
+        document.querySelector('body').appendChild(textArea);
+      });
+
+      afterAll(() => {
+        textArea.parentNode.removeChild(textArea);
+      });
+
+      describe('without selection', () => {
+        it('inserts the tag on an empty line', () => {
+          const initialValue = '';
+
+          textArea.value = initialValue;
+          textArea.selectionStart = 0;
+          textArea.selectionEnd = 0;
+
+          gl.text.insertText(textArea, textArea.value, '*', null, '', false);
+
+          expect(textArea.value).toEqual(`${initialValue}* `);
+        });
+
+        it('inserts the tag on a new line if the current one is not empty', () => {
+          const initialValue = 'some text';
+
+          textArea.value = initialValue;
+          textArea.setSelectionRange(initialValue.length, initialValue.length);
+
+          gl.text.insertText(textArea, textArea.value, '*', null, '', false);
+
+          expect(textArea.value).toEqual(`${initialValue}\n* `);
+        });
+
+        it('inserts the tag on the same line if the current line only contains spaces', () => {
+          const initialValue = '  ';
+
+          textArea.value = initialValue;
+          textArea.setSelectionRange(initialValue.length, initialValue.length);
+
+          gl.text.insertText(textArea, textArea.value, '*', null, '', false);
+
+          expect(textArea.value).toEqual(`${initialValue}* `);
+        });
+
+        it('inserts the tag on the same line if the current line only contains tabs', () => {
+          const initialValue = '\t\t\t';
+
+          textArea.value = initialValue;
+          textArea.setSelectionRange(initialValue.length, initialValue.length);
+
+          gl.text.insertText(textArea, textArea.value, '*', null, '', false);
+
+          expect(textArea.value).toEqual(`${initialValue}* `);
+        });
+      });
+    });
   });
 })();