Fix getString output type & clarify fullText attachment

Author: 2007heaven

packages/devtools-reps/src/object-inspector/utils/client.js

@@ -84,7 +84,7 @@ async function getPrototype(
 async function getFullText(
   objectClient: ObjectClient,
   object: NodeContents,
-) : Promise<string> {
+) : Promise<?string | {}> {
   if (typeof objectClient.getString !== "function") {
     console.error("objectClient.getString is not a function");
     return Promise.resolve({});

packages/devtools-reps/src/object-inspector/utils/node.js

@@ -225,8 +225,8 @@ function nodeIsLongString(
 function nodeHasFullText(
   item: Node
 ) : boolean {
-  return nodeIsLongString(item)
-    && getValue(item).hasOwnProperty("fullText");
+  const value = getValue(item);
+  return nodeIsLongString(item) && value.hasOwnProperty("fullText");
 }
 
 function nodeHasAccessors(item: Node) : boolean {
@@ -740,6 +740,7 @@ function getChildren(options: {
   }
 
   if (nodeIsLongString(item) && hasLoadedProps) {
+    // Set longString object's fullText to fetched one.
     item.contents.value.fullText = loadedProps.fullText;
     return addToCache(item);
   }