code docs

src/hydrate/runner/window-initialize.ts

@@ -4,7 +4,11 @@ import { STENCIL_DOC_DATA } from 'src/runtime/runtime-constants';
 import type * as d from '../../declarations';
 import { runtimeLogging } from './runtime-log';
 
-const docData = {
+/**
+ * Maintain a unqiue `docData` object across multiple hydration runs
+ * to ensure that host ids remain unique.
+ */
+const docData: d.DocData = {
   hostIds: 0,
   rootLevelIds: 0,
   staticComponents: new Set<string>(),
@@ -65,9 +69,6 @@ export function initializeWindow(
 
   runtimeLogging(win, opts, results);
 
-  /**
-   * apply the hydrate host id so that
-   */
   (doc as d.StencilDocument)[STENCIL_DOC_DATA] = docData;
 
   return win;

src/runtime/vdom/vdom-annotations.ts

@@ -25,6 +25,10 @@ import { insertBefore } from './vdom-render';
  */
 export const insertVdomAnnotations = (doc: Document, staticComponents: string[]) => {
   if (doc != null) {
+    /**
+     * Initiated `docData` object from the document if it exists to ensure we
+     * maintain the same `docData` object across multiple hydration hydration runs.
+     */
     const docData: d.DocData = STENCIL_DOC_DATA in doc ? (doc[STENCIL_DOC_DATA] as d.DocData) : { ...DEFAULT_DOC_DATA };
     docData.staticComponents = new Set(staticComponents);
     const orgLocationNodes: d.RenderNode[] = [];