test: add tests for rendererChildren (#52)

* test: [wip] add tests for rendererChildren

* chore: use serializeInner for clearer output

* fix: should remove the text node if content is empty

* test: also test for appended content

* test: inserting & removing

* test: moving children

* refactor: use a helper function

* test: finish tests

* test: duplicate keys tests belong to keyed children block

* fix(runtime-test): fix insert when moving node in the same parent

* fix: fix failing test cases for rendererChildren

* test: handle rendererChildren edge case

packages/runtime-test/src/nodeOps.ts

@@ -155,7 +155,9 @@ function insert(child: TestNode, parent: TestElement, ref?: TestNode | null) {
   })
   // remove the node first, but don't log it as a REMOVE op
   remove(child, false)
-  if (refIndex === undefined) {
+  // re-calculate the ref index because the child's removal may have affected it
+  refIndex = ref ? parent.children.indexOf(ref) : -1
+  if (refIndex === -1) {
     parent.children.push(child)
     child.parentNode = parent
   } else {
@@ -195,14 +197,18 @@ function setElementText(el: TestElement, text: string) {
   el.children.forEach(c => {
     c.parentNode = null
   })
-  el.children = [
-    {
-      id: nodeId++,
-      type: NodeTypes.TEXT,
-      text,
-      parentNode: el
-    }
-  ]
+  if (!text) {
+    el.children = []
+  } else {
+    el.children = [
+      {
+        id: nodeId++,
+        type: NodeTypes.TEXT,
+        text,
+        parentNode: el
+      }
+    ]
+  }
 }
 
 function parentNode(node: TestNode): TestElement | null {