added support for deleting selection properties by setting them to null (#4109)

added tests for setting and deleting custom selection props

packages/slate/src/transforms/general.ts

@@ -212,7 +212,8 @@ export const GeneralTransforms: GeneralTransforms = {
 
         if (newProperties == null) {
           selection = newProperties
-        } else if (selection == null) {
+        } else {
+          if (selection == null) {
             if (!Range.isRange(newProperties)) {
               throw new Error(
                 `Cannot apply an incomplete "set_selection" operation properties ${JSON.stringify(
@@ -221,9 +222,22 @@ export const GeneralTransforms: GeneralTransforms = {
               )
             }
 
-          selection = newProperties
+            selection = { ...newProperties }
+          }
+
+          for (const key in newProperties) {
+            const value = newProperties[key]
+
+            if (value == null) {
+              if (key === 'anchor' || key === 'focus') {
+                throw new Error(`Cannot remove the "${key}" selection property`)
+              }
+
+              delete selection[key]
             } else {
-          Object.assign(selection, newProperties)
+              selection[key] = value
+            }
+          }
         }
 
         break

packages/slate/test/operations/set_selection/custom-props.tsx

@@ -0,0 +1,29 @@
+/** @jsx jsx */
+import { jsx } from 'slate-hyperscript'
+import { Transforms, Editor } from 'slate'
+
+export const input = (
+  <editor>
+    <element>
+      a<cursor />
+    </element>
+  </editor>
+)
+
+export const operations = [
+  {
+    type: 'set_selection',
+    oldProperties: {},
+    newProperties: { custom: 123 },
+  },
+]
+
+export const output = (
+  <editor>
+    <element>
+      a<cursor />
+    </element>
+  </editor>
+)
+
+Transforms.setSelection(output, { custom: 123 })

packages/slate/test/operations/set_selection/remove.tsx

@@ -0,0 +1,29 @@
+/** @jsx jsx */
+import { jsx } from 'slate-hyperscript'
+import { Transforms, Editor } from 'slate'
+
+export const input = (
+  <editor>
+    <element>
+      a<cursor />
+    </element>
+  </editor>
+)
+
+Transforms.setSelection(input, { custom: 123 })
+
+export const operations = [
+  {
+    type: 'set_selection',
+    oldProperties: {},
+    newProperties: { custom: null },
+  },
+]
+
+export const output = (
+  <editor>
+    <element>
+      a<cursor />
+    </element>
+  </editor>
+)