fix undoing removing text with marks, closes #350

src/transforms/operations.js

@@ -250,14 +250,18 @@ export function removeTextOperation(transform, path, offset, length) {
   const ranges = node.getRanges()
   const inverse = []
 
+  // Loop the ranges of text in the node, creating inverse insert operations for
+  // each of the ranges that overlap with the remove operation. This is
+  // necessary because insert's can only have a single set of marks associated
+  // with them, but removes can remove many.
   ranges.reduce((start, range) => {
     const { text, marks } = range
     const end = start + text.length
-    if (start > offset + length) return
+    if (start > offset + length) return end
-    if (end <= offset) return
+    if (end <= offset) return end
 
     const endOffset = Math.min(end, offset + length)
-    const string = text.slice(offset, endOffset)
+    const string = text.slice(offset - start, endOffset - start)
 
     inverse.push({
       type: 'insert_text',

test/transforms/fixtures/on-history/undo/delete-text-with-marks/index.js

@@ -0,0 +1,26 @@
+
+import assert from 'assert'
+
+export default function (state) {
+  const { document, selection } = state
+  const texts = document.getTexts()
+  const first = texts.first()
+
+  const next = state
+    .transform()
+    .moveTo({
+      anchorKey: first.key,
+      anchorOffset: 10,
+      focusKey: first.key,
+      focusOffset: 10
+    })
+    .deleteBackward()
+    .apply()
+
+    .transform()
+    .undo()
+    .apply()
+
+  assert.deepEqual(next.selection.toJS(), selection.toJS())
+  return next
+}

test/transforms/fixtures/on-history/undo/delete-text-with-marks/input.yaml

@@ -0,0 +1,19 @@
+
+nodes:
+  - kind: block
+    type: paragraph
+    nodes:
+      - kind: text
+        ranges:
+          - text: one
+            marks:
+              - type: bold
+          - text: two
+            marks:
+              - type: underlined
+          - text: three
+            marks:
+              - type: italic
+          - text: four
+            marks:
+              - type: bold

test/transforms/fixtures/on-history/undo/delete-text-with-marks/output.yaml

@@ -0,0 +1,19 @@
+
+nodes:
+  - kind: block
+    type: paragraph
+    nodes:
+      - kind: text
+        ranges:
+          - text: one
+            marks:
+              - type: bold
+          - text: two
+            marks:
+              - type: underlined
+          - text: three
+            marks:
+              - type: italic
+          - text: four
+            marks:
+              - type: bold