Fix node.isEmpty (#1718)

* add test for normalization of nested empty inlines

* fix normalization of nested empty inlines

* add test for normalization of inlines with empty void

* fix normalization of inlines containing empty void

* fix linting errors

* Fix node.isEmpty to work properly with void nodes of zero text length

* Take adavantage of fixed node.isEmpty to simplify normalization of empty inlines

* Fix linting errors

packages/slate/src/constants/core-schema-rules.js

@@ -106,19 +106,8 @@ const CORE_SCHEMA_RULES = [
     validateNode(node) {
       if (node.object != 'inline' && node.object != 'block') return
 
-      function isEmpty(n) {
-        // text node is empty when text is empty
-        if (n.object === 'text') {
-          return n.text === ''
-        }
-        // void is always considered non-empty regardless of actual content
-        if (n.isVoid) return false
-        // otherwise node is empty if all children are empty
-        return !n.nodes.some(child => !isEmpty(child))
-      }
-
       const invalids = node.nodes.filter(
-        child => child.object === 'inline' && isEmpty(child)
+        child => child.object === 'inline' && child.isEmpty
       )
 
       if (!invalids.size) return

packages/slate/src/models/block.js

@@ -163,12 +163,14 @@ class Block extends Record(DEFAULTS) {
 
   /**
    * Check if the block is empty.
+   * Returns true if block is not void and all it's children nodes are empty.
+   * Void node is never empty, regardless of it's content.
    *
    * @return {Boolean}
    */
 
   get isEmpty() {
-    return this.text == ''
+    return !this.isVoid && !this.nodes.some(child => !child.isEmpty)
   }
 
   /**

packages/slate/src/models/document.js

@@ -121,12 +121,13 @@ class Document extends Record(DEFAULTS) {
 
   /**
    * Check if the document is empty.
+   * Returns true if all it's children nodes are empty.
    *
    * @return {Boolean}
    */
 
   get isEmpty() {
-    return this.text == ''
+    return !this.nodes.some(child => !child.isEmpty)
   }
 
   /**

packages/slate/src/models/inline.js

@@ -163,12 +163,14 @@ class Inline extends Record(DEFAULTS) {
 
   /**
    * Check if the inline is empty.
+   * Returns true if inline is not void and all it's children nodes are empty.
+   * Void node is never empty, regardless of it's content.
    *
    * @return {Boolean}
    */
 
   get isEmpty() {
-    return this.text == ''
+    return !this.isVoid && !this.nodes.some(child => !child.isEmpty)
   }
 
   /**

packages/slate/src/models/value.js

@@ -603,7 +603,7 @@ class Value extends Record(DEFAULTS) {
   get isEmpty() {
     if (this.isCollapsed) return true
     if (this.endOffset != 0 && this.startOffset != 0) return false
-    return this.fragment.text.length == 0
+    return this.fragment.isEmpty
   }
 
   /**