prelim refactor commit

src/utils/YEvent.js

@@ -1,3 +1,6 @@
+import { AbstractItem } from '../structs/AbstractItem.js' // eslint-disable-line
+import { AbstractType } from '../types/AbstractType.js' // eslint-disable-line
+
 /**
  * @module utils
  */
@@ -7,17 +10,17 @@
  */
 export class YEvent {
   /**
-   * @param {Type} target The changed type.
+   * @param {AbstractType} target The changed type.
    */
   constructor (target) {
     /**
      * The type on which this event was created on.
-     * @type {Type}
+     * @type {AbstractType}
      */
     this.target = target
     /**
      * The current target on which the observe callback is called.
-     * @type {Type}
+     * @type {AbstractType}
      */
     this.currentTarget = target
   }
@@ -34,6 +37,48 @@ export class YEvent {
    *   type === event.target // => true
    */
   get path () {
-    return this.currentTarget.getPathTo(this.target)
+    // @ts-ignore _item is defined because target is integrated
+    return getPathTo(this.currentTarget, this.target._item)
+  }
+}
+
+/**
+ * Compute the path from this type to the specified target.
+ *
+ * @example
+ *   // `child` should be accessible via `type.get(path[0]).get(path[1])..`
+ *   const path = type.getPathTo(child)
+ *   // assuming `type instanceof YArray`
+ *   console.log(path) // might look like => [2, 'key1']
+ *   child === type.get(path[0]).get(path[1])
+ *
+ * @param {AbstractType} parent
+ * @param {AbstractItem} child target
+ * @return {Array<string|number>} Path to the target
+ */
+const getPathTo = (parent, child) => {
+  const path = []
+  while (true) {
+    const cparent = child.parent
+    if (child.parentSub !== null) {
+      // parent is map-ish
+      path.unshift(child.parentSub)
+    } else {
+      // parent is array-ish
+      let i = 0
+      let c = cparent._start
+      while (c !== child && c !== null) {
+        if (!c.deleted) {
+          i++
+        }
+        c = c.right
+      }
+      path.unshift(i)
+    }
+    if (parent === cparent) {
+      return path
+    }
+    // @ts-ignore parent._item cannot be null, because it is integrated
+    child = parent._item
   }
 }