DevTools: fix race when revealing formatted source code

third_party/WebKit/Source/devtools/front_end/coverage/CoverageListView.js

 // Copyright (c) 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 Coverage.CoverageListView = class extends UI.VBox {
   constructor() {
     super(true);
     /** @type {!Map<!Coverage.URLCoverageInfo, !Coverage.CoverageListView.GridNode>} */
     this._nodeForCoverageInfo = new Map();
     /** @type {?RegExp} */
@@ skipping 77 matching lines @@
       hadTreeUpdates = true;
       if (!shouldBeVisible)
         node.remove();
       else
         this._dataGrid.rootNode().appendChild(node);
     }
     if (hadTreeUpdates)
       this._sortingChanged();
   }
 
-  /**
-   * @param {!Common.Event} event
-   */
-  _onOpenedNode(event) {
-    var node = /** @type Coverage.CoverageListView.GridNode */ (event.data);
-    this._revealSourceForNode(node);
+  _onOpenedNode() {
+    this._revealSourceForSelectedNode();
   }
 
   /**
    * @param {!Coverage.CoverageListView.GridNode} node
    * @return {boolean}
    */
   _isVisible(node) {
     return !this._filterRegExp || this._filterRegExp.test(node._url);
   }
 
   /**
    * @param {!Event} event
    */
   _onKeyDown(event) {
     if (!isEnterKey(event))
       return;
     event.consume(true);
-    this._revealSourceForNode(this._dataGrid.selectedNode);
+    this._revealSourceForSelectedNode();
   }
 
-  /**
-   * @param {?DataGrid.DataGridNode} node
-   */
-  async _revealSourceForNode(node) {
+  async _revealSourceForSelectedNode() {

[lushnikov, 2017/05/17 23:39:08]

is this change necessary?

[caseq, 2017/05/18 02:04:37]

This is not directly related, but seems like a reasonable drive-by -- we don't
want late "reveal" to be completed if user navigated away.

+    var node = this._dataGrid.selectedNode;
     if (!node)
       return;
     var coverageInfo = /** @type {!Coverage.CoverageListView.GridNode} */ (node)._coverageInfo;
     var sourceCode = Workspace.workspace.uiSourceCodeForURL(coverageInfo.url());
     if (!sourceCode)
       return;
     var content = await sourceCode.requestContent();
     if (TextUtils.isMinified(content)) {
       var formatData = await Sources.sourceFormatter.format(sourceCode);

[lushnikov, 2017/05/17 23:39:08]

not: as per decision taken in performance-room, we now should put '// -----
ASYNC ------ comment before every await statement

[caseq, 2017/05/18 02:04:37]

Done.

-      Common.Revealer.reveal(formatData.formattedSourceCode);
-    } else {
-      Common.Revealer.reveal(sourceCode);
+      sourceCode = formatData.formattedSourceCode;
     }
+    if (this._dataGrid.selectedNode !== node)
+      return;
+    Common.Revealer.reveal(sourceCode);
   }
 
   _sortingChanged() {
     var columnId = this._dataGrid.sortColumnId();
     if (!columnId)
       return;
     var sortFunction;
     switch (columnId) {
       case 'url':
         sortFunction = compareURL;
@@ skipping 154 matching lines @@
    * @param {string} textContent
    */
   _highlight(element, textContent) {
     var matches = this._highlightRegExp.exec(textContent);
     if (!matches || !matches.length)
       return;
     var range = new TextUtils.SourceRange(matches.index, matches[0].length);
     UI.highlightRangesWithStyleClass(element, [range], 'filter-highlight');
   }
 };