Protection against current code-block removing

lib/__tests__/handleKeyCommand.js

@@ -1,4 +1,9 @@
-const { EditorState, ContentState, SelectionState } = require('draft-js');
+const {
+  EditorState,
+  ContentState,
+  ContentBlock,
+  SelectionState
+} = require('draft-js');
 const handleKeyCommand = require('../handleKeyCommand');
 
 const toPlainText = editorState =>
@@ -119,6 +124,39 @@ it('should not do anything on backspace if something is selected', () => {
   expect(handleKeyCommand(editorState, 'backspace')).toEqual(undefined);
 });
 
+it('should skip handling when text beginning from the content-block beginning', () => {
+  const firstBlock = new ContentBlock({
+    key: 'a1',
+    text: 'const a = 1;',
+    type: 'unstyled'
+  });
+  const secondBlock = new ContentBlock({
+    key: 'a2',
+    text: 'function () {',
+    type: 'code-block'
+  });
+  const currentContent = ContentState.createFromBlockArray([
+    firstBlock,
+    secondBlock
+  ]);
+  const selectSecondBlock = SelectionState.createEmpty(
+    currentContent
+      .getBlockMap()
+      .last()
+      .getKey()
+  )
+    .set('anchorOffset', 0)
+    .set('focusOffset', 0);
+  const editorState = EditorState.create({
+    allowUndo: true,
+    currentContent,
+    selection: selectSecondBlock
+  });
+
+  const after = handleKeyCommand(editorState, 'backspace');
+  expect(toPlainText(after)).toEqual(toPlainText(editorState));
+});
+
 it('should not do anything for any other command', () => {
   const editorState = createWithText('');
   expect(handleKeyCommand(editorState, 'enter')).toEqual(undefined);

lib/utils/getLineAnchorForOffset.js

@@ -40,7 +40,7 @@ function getLineAnchorForOffset(text, offset, sep) {
   }
 
   return new LineAnchor({
-    line: lineIndex - 1,
+    line: lineIndex === 0 ? 0 : lineIndex - 1,
     offset: offset - lastLineIndex
   });
 }

lib/utils/removeIndent.js

@@ -1,5 +1,6 @@
 var Draft = require('draft-js');
 var endsWith = require('ends-with');
+var detectIndent = require('detect-indent');
 
 var getNewLine = require('./getNewLine');
 var getIndentation = require('./getIndentation');
@@ -25,7 +26,6 @@ function removeIndent(editorState) {
   var currentBlock = contentState.getBlockForKey(startKey);
   var blockText = currentBlock.getText();
 
-  // Detect newline separator and indentation
   var newLine = getNewLine(blockText);
   var indent = getIndentation(blockText);
 
@@ -36,6 +36,31 @@ function removeIndent(editorState) {
   var currentLine = lines.get(lineAnchor.getLine());
   var beforeSelection = currentLine.slice(0, lineAnchor.getOffset());
 
+  // Detect newline separator and indentation
+  var currentIndent = detectIndent(currentLine);
+
+  // if previous block was not `code-block` and we are at the beginning of line,
+  // we don't do any action to prevent current `code-block` removing
+  if (
+    currentIndent.amount < 1 &&
+    lineAnchor.getLine() === 0 &&
+    startOffset === 0
+  ) {
+    var lastBlockBefore = contentState
+      .getBlockMap()
+      .takeUntil((value, key) => {
+        return key.match(startKey);
+      })
+      .last();
+
+    if (
+      !(lastBlockBefore instanceof Draft.ContentBlock) ||
+      lastBlockBefore.getType() !== 'code-block'
+    ) {
+      return editorState;
+    }
+  }
+
   // If the line before selection ending with the indentation?
   if (!endsWith(beforeSelection, indent)) {
     return;