Move selection to the offset of remove_text if it's in its bounds

If selection is inside a block of text that's removed, the part of the
selection that's inside the bounds should clamp to the offset of the
removed text. So if your cursor is at offset 5, and you're deleting
from 2-10, your cursor should end up at offset 2.

packages/slate/src/operations/apply.js

@@ -287,12 +287,20 @@ const APPLIERS = {
     const { anchorKey, focusKey, anchorOffset, focusOffset } = selection
     let node = document.assertPath(path)
 
-    if (anchorKey == node.key && anchorOffset >= rangeOffset) {
-      selection = selection.moveAnchor(-length)
+    if (anchorKey == node.key) {
+      if (anchorOffset >= rangeOffset) {
+        selection = selection.moveAnchor(-length)
+      } else if (anchorOffset > offset) {
+        selection = selection.moveAnchorTo(anchorKey, offset)
+      }
     }
 
-    if (focusKey == node.key && focusOffset >= rangeOffset) {
-      selection = selection.moveFocus(-length)
+    if (focusKey == node.key) {
+      if (focusOffset >= rangeOffset) {
+        selection = selection.moveFocus(-length)
+      } else if (focusOffset > offset) {
+        selection = selection.moveFocusTo(focusKey, offset)
+      }
     }
 
     node = node.removeText(offset, length)

packages/slate/test/index.js

@@ -20,6 +20,7 @@ describe('slate', () => {
   require('./schema')
   require('./changes')
   require('./history')
+  require('./operations')
 })
 
 /**

packages/slate/test/operations/apply/remove_text/cursor-inside-removed-text.js

@@ -0,0 +1,33 @@
+/** @jsx h */
+
+import h from '../../../helpers/h'
+
+export default function (change) {
+  return change.applyOperation({
+    type: 'remove_text',
+    path: [0, 0],
+    offset: 2,
+    text: 'is is some text inside ',
+    marks: []
+  })
+}
+
+export const input = (
+  <value>
+    <document>
+      <paragraph>
+        This <cursor />is some text inside a paragraph.
+      </paragraph>
+    </document>
+  </value>
+)
+
+export const output = (
+  <value>
+    <document>
+      <paragraph>
+        Th<cursor />a paragraph.
+      </paragraph>
+    </document>
+  </value>
+)

packages/slate/test/operations/index.js

@@ -0,0 +1,42 @@
+
+import assert from 'assert'
+import fs from 'fs-promise' // eslint-disable-line import/no-extraneous-dependencies
+import toCamel from 'to-camel-case' // eslint-disable-line import/no-extraneous-dependencies
+import { basename, extname, resolve } from 'path'
+
+/**
+ * Tests.
+ */
+
+describe('operations', async () => {
+  const dir = resolve(__dirname)
+  const categories = fs.readdirSync(dir).filter(c => c[0] != '.' && c != 'index.js')
+
+  for (const category of categories) {
+    describe(category, () => {
+      const categoryDir = resolve(dir, category)
+      const methods = fs.readdirSync(categoryDir).filter(c => c[0] != '.')
+
+      for (const method of methods) {
+        describe(toCamel(method), () => {
+          const testDir = resolve(categoryDir, method)
+          const tests = fs.readdirSync(testDir).filter(t => t[0] != '.' && !!~t.indexOf('.js')).map(t => basename(t, extname(t)))
+
+          for (const test of tests) {
+            it(test, async () => {
+              const module = require(resolve(testDir, test))
+              const { input, output } = module
+              const fn = module.default
+              const change = input.change()
+              fn(change)
+              const opts = { preserveSelection: true, preserveData: true }
+              const actual = change.value.toJSON(opts)
+              const expected = output.toJSON(opts)
+              assert.deepEqual(actual, expected)
+            })
+          }
+        })
+      }
+    })
+  }
+})