Change Team Drives check to be asynchronous

Without this patch, shouldShowTeamDrives_ calls |callback| synchronously
when the --team-drives flag is disabled, and asynchronously if it is
enabled. The asynchronous call causes the navigation tree to updated
after the appropriate update methods are called, which causes undefined
behaviour.

This patch moves the check for Team Drives into an asynchronous function
called *after* the tree has been synchronously initialized, and simply
shows the element if the user has Team Drives (originally, it hid the
element, but this means the item may be visible for a split-second. To
fix this, it is added as a hidden element by default and then unhidden
after the check).

This also fixes the existing integration tests to work with the
--team-drives flag enabled.

Bug: 849497
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: Ie8e174995ca8b16371f32e8ab780f45748fcc55e
Reviewed-on: https://chromium-review.googlesource.com/1103983
Commit-Queue: Sasha Morrissey <sashab@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568336}

ui/file_manager/file_manager/foreground/js/ui/directory_tree.js

@@ -810,27 +810,28 @@ DriveVolumeItem.prototype.handleClick = function(e) {
 };
 
 /**
- * Checks whether the Team Drives grand root should be shown.
- * We show the Team Drives grand root if the user has at least one Team Drive.
+ * Sets the hidden state of the given item depending on whether the user has any
+ * Team Drives.
  *
- * @param {function(boolean)} callback Called with True if the grand root and
- *     its subtree should be shown, false if not.
+ * Since we don't currently support any functionality with just the grand root
+ * (e.g. you can't create a new team drive from the root yet), hide the grand
+ * root unless the user has at least one Team Drive. If there is at least one
+ * Team Drive, show it.
+ *
+ * @param {!DirectoryItem} teamDrivesGrandRootItem The item to show if there is
+ *     at least one Team Drive, or hide if not.
  * @private
  */
-DriveVolumeItem.prototype.shouldShowTeamDrives_ = function(callback) {
+DriveVolumeItem.prototype.setHiddenForTeamDrivesGrandRoot_ = function(
+    teamDrivesGrandRootItem) {
   var teamDriveEntry = this.volumeInfo_.teamDriveDisplayRoot;
-  if (!teamDriveEntry) {
-    callback(false);
-  } else {
-    // Don't show the Team Drives root unless the user has at least one team
-    // drive, since we don't currently support any functionality with just the
-    // grand root (e.g. you can't create a new team drive from the root yet).
-    var reader = teamDriveEntry.createReader();
-    reader.readEntries(function(results) {
-      metrics.recordSmallCount('TeamDrivesCount', results.length);
-      callback(results.length > 0);
-    });
-  }
+  if (!teamDriveEntry)
+    return;
+  var reader = teamDriveEntry.createReader();
+  reader.readEntries(function(results) {
+    metrics.recordSmallCount('TeamDrivesCount', results.length);
+    teamDrivesGrandRootItem.hidden = results.length == 0;
+  });
 };
 
 /**
@@ -841,35 +842,46 @@ DriveVolumeItem.prototype.shouldShowTeamDrives_ = function(callback) {
 DriveVolumeItem.prototype.updateSubDirectories = function(recursive) {
   if (!this.entry || this.hasChildren)
     return;
-  this.shouldShowTeamDrives_(function(shouldShowTeamDrives) {
-    var entries = [this.entry];
-    if (shouldShowTeamDrives)
-      entries.push(this.volumeInfo_.teamDriveDisplayRoot);
-    // Drive volume has children including fake entries (offline, recent, ...)
-    var fakeEntries = [];
-    if (this.parentTree_.fakeEntriesVisible_) {
-      for (var key in this.volumeInfo_.fakeEntries)
-        fakeEntries.push(this.volumeInfo_.fakeEntries[key]);
-      // This list is sorted by URL on purpose.
-      fakeEntries.sort(function(a, b) {
-        if (a.toURL() === b.toURL())
-          return 0;
-        return b.toURL() > a.toURL() ? 1 : -1;
-      });
-      entries = entries.concat(fakeEntries);
-    }
 
-    for (var i = 0; i < entries.length; i++) {
-      var item = new SubDirectoryItem(
-          util.getEntryLabel(
-              this.parentTree_.volumeManager_.getLocationInfo(entries[i]),
-              entries[i]) || '',
-          entries[i], this, this.parentTree_);
-      this.add(item);
-      item.updateSubDirectories(false);
+  var entries = [this.entry];
+
+  var teamDrivesDisplayRoot = this.volumeInfo_.teamDriveDisplayRoot;
+  if (!!teamDrivesDisplayRoot) {
+    entries.push(teamDrivesDisplayRoot);
+  }
+
+  // Drive volume has children including fake entries (offline, recent, ...)
+  var fakeEntries = [];
+  if (this.parentTree_.fakeEntriesVisible_) {
+    for (var key in this.volumeInfo_.fakeEntries)
+      fakeEntries.push(this.volumeInfo_.fakeEntries[key]);
+    // This list is sorted by URL on purpose.
+    fakeEntries.sort(function(a, b) {
+      if (a.toURL() === b.toURL())
+        return 0;
+      return b.toURL() > a.toURL() ? 1 : -1;
+    });
+    entries = entries.concat(fakeEntries);
+  }
+
+  for (var i = 0; i < entries.length; i++) {
+    var item = new SubDirectoryItem(
+        util.getEntryLabel(
+            this.parentTree_.volumeManager_.getLocationInfo(entries[i]),
+            entries[i]) ||
+            '',
+        entries[i], this, this.parentTree_);
+
+    // Hide the team drives root in case we have no team drives.
+    if (entries[i] === teamDrivesDisplayRoot) {
+      item.hidden = true;
+      this.setHiddenForTeamDrivesGrandRoot_(item);
     }
-    this.expanded = true;
-  }.bind(this));
+
+    this.add(item);
+    item.updateSubDirectories(false);
+  }
+  this.expanded = true;
 };
 
 /**

ui/file_manager/file_manager/foreground/js/ui/directory_tree_unittest.js

@@ -238,15 +238,21 @@ function testCreateDirectoryTreeWithEmptyTeamDrive(callback) {
 
   reportPromise(
       waitUntil(function() {
-        // Root entries under Drive volume is generated except Team Drives.
+        // Root entries under Drive volume is generated, plus Team Drives.
         // See testCreateDirectoryTreeWithTeamDrive for detail.
-        return driveItem.items.length == 3;
+        return driveItem.items.length == 4;
       }).then(function() {
+        var teamDrivesItemFound = false;
         for (var i = 0; i < driveItem.items.length; i++) {
-          assertFalse(
-              driveItem.items[i].label == str('DRIVE_TEAM_DRIVES_LABEL'),
-              'Team Drives node should not be shown');
+          if (driveItem.items[i].label == str('DRIVE_TEAM_DRIVES_LABEL')) {
+            assertEquals(
+                true, driveItem.items[i].hidden,
+                'Team Drives node should not be shown');
+            teamDrivesItemFound = true;
+            break;
+          }
         }
+        assertTrue(teamDrivesItemFound, 'Team Drives node should be generated');
       }),
       callback);
 }