Don't switch to the default display root if the current entry is fake.

If a FakeItem is the current entry and a volume is mounted or unmounted,
Files app switches to the default display root since the FakeItem
doesn't have a VolumeInfo. Omit switching if the current root is not a
native entry.

Bug: 900870
Change-Id: I943959112135ceb5752207f87e6810a4ec60ae0f
Reviewed-on: https://chromium-review.googlesource.com/c/1312148
Commit-Queue: Sam McNally <sammc@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605221}

chrome/browser/chromeos/file_manager/file_manager_browsertest.cc

@@ -212,6 +212,7 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
         TestCase("fileDisplayWithoutVolumesThenMountDrive").EnableDriveFs(),
         TestCase("fileDisplayWithoutDrive"),
         TestCase("fileDisplayWithoutDriveThenDisable"),
+        TestCase("fileDisplayMountWithFakeItemSelected"),
         TestCase("fileSearchCaseInsensitive"),
         TestCase("fileSearchNotFound")));
 

ui/file_manager/file_manager/foreground/js/directory_model.js

@@ -1203,13 +1203,28 @@ DirectoryModel.prototype.onVolumeInfoListUpdated_ = function(event) {
   // root. If current directory path is empty, stop the fallback
   // since the current directory is initializing now.
   const entry = this.getCurrentDirEntry();
-  if (entry && !this.volumeManager_.getVolumeInfo(entry)) {
+  if (entry && util.isNativeEntry(entry) &&
+      !this.volumeManager_.getVolumeInfo(entry)) {
     this.volumeManager_.getDefaultDisplayRoot((displayRoot) => {
       if (displayRoot)
         this.changeDirectoryEntry(displayRoot);
     });
   }
 
+  // If a volume within My files is mounted, rescan the contents.
+  // TODO(crbug.com/901690): Remove this special case.
+  if (this.getCurrentRootType() === VolumeManagerCommon.RootType.MY_FILES) {
+    for (let newVolume of event.added) {
+      if (newVolume.volumeType === VolumeManagerCommon.VolumeType.DOWNLOADS ||
+          newVolume.volumeType ===
+              VolumeManagerCommon.VolumeType.ANDROID_FILES ||
+          newVolume.volumeType === VolumeManagerCommon.VolumeType.CROSTINI) {
+        this.rescan(false);
+        break;
+      }
+    }
+  }
+
   // If the current directory is the Drive placeholder and the real Drive is
   // mounted, switch to it.
   if (this.getCurrentRootType() ===

ui/file_manager/integration_tests/file_manager/file_display.js

@@ -504,14 +504,18 @@ testcase.fileDisplayWithoutVolumesThenMountDownloads = function() {
     function() {
       sendTestMessage({name: 'mountDownloads'}).then(this.next);
     },
-    // Add an entry to Downloads.
+    // Downloads should appear in My files in the directory tree.
     function() {
-      addEntries(['local'], [ENTRIES.newlyAdded], this.next);
+      remoteCall.waitForElement(appId, '[volume-type-for-testing="downloads"]')
+          .then(this.next);
     },
-    // Because Downloads is the default volume it will be automatically
-    // selected, so let's wait for its entry to appear.
     function() {
-      remoteCall.waitForFiles(appId, [ENTRIES.newlyAdded.getExpectedRow()])
+      const downloadsRow = ['Downloads', '--', 'Folder'];
+      const crostiniRow = ['Linux files', '--', 'Folder'];
+      remoteCall
+          .waitForFiles(
+              appId, [downloadsRow, crostiniRow],
+              {ignoreFileSize: true, ignoreLastModifiedTime: true})
           .then(this.next);
     },
     function() {
@@ -560,8 +564,7 @@ testcase.fileDisplayWithoutVolumesThenMountDrive = function() {
     // Navigate to the Drive FakeItem.
     function() {
       remoteCall.callRemoteTestUtil(
-          'fakeMouseClick', appId, ['span[root-type-icon=\'drive\']'],
-          this.next);
+          'fakeMouseClick', appId, ['[root-type-icon=\'drive\']'], this.next);
     },
     // The fake Google Drive should be empty.
     function() {
@@ -630,8 +633,7 @@ testcase.fileDisplayWithoutDrive = function() {
     // Navigate to Drive.
     function() {
       remoteCall.callRemoteTestUtil(
-          'fakeMouseClick', appId, ['span[root-type-icon=\'drive\']'],
-          this.next);
+          'fakeMouseClick', appId, ['[root-type-icon=\'drive\']'], this.next);
     },
     function() {
       remoteCall.waitUntilCurrentDirectoryIsChanged(appId, '/Google Drive')
@@ -705,8 +707,7 @@ testcase.fileDisplayWithoutDriveThenDisable = function() {
     // Navigate to Drive.
     function() {
       remoteCall.callRemoteTestUtil(
-          'fakeMouseClick', appId, ['span[root-type-icon=\'drive\']'],
-          this.next);
+          'fakeMouseClick', appId, ['[root-type-icon=\'drive\']'], this.next);
     },
     // The fake Google Drive should be empty.
     function() {
@@ -734,7 +735,7 @@ testcase.fileDisplayWithoutDriveThenDisable = function() {
     },
     // Wait for the fake drive to reappear.
     function() {
-      remoteCall.waitForElement(appId, ['span[root-type-icon=\'drive\']'])
+      remoteCall.waitForElement(appId, ['[root-type-icon=\'drive\']'])
           .then(this.next);
     },
     function() {
@@ -742,3 +743,55 @@ testcase.fileDisplayWithoutDriveThenDisable = function() {
     },
   ]);
 };
+
+/**
+ * Tests Files app resisting the urge to switch to Downloads when mounts change.
+ * re-enabling Drive.
+ */
+testcase.fileDisplayMountWithFakeItemSelected = function() {
+  let appId = null;
+
+  StepsRunner.run([
+    // Open Files app on Drive with the given test files.
+    function() {
+      setupAndWaitUntilReady(
+          null, RootPath.DOWNLOADS, this.next, [ENTRIES.newlyAdded], []);
+    },
+    // Ensure Downloads has loaded.
+    function(result) {
+      appId = result.windowId;
+      remoteCall.waitForFiles(appId, [ENTRIES.newlyAdded.getExpectedRow()])
+          .then(this.next);
+    },
+    // Navigate to My files.
+    function() {
+      remoteCall.callRemoteTestUtil(
+          'fakeMouseClick', appId, ['[root-type-icon=\'my_files\']'],
+          this.next);
+    },
+    // Wait for the navigation to complete.
+    function() {
+      remoteCall.waitUntilCurrentDirectoryIsChanged(appId, '/My files')
+          .then(this.next);
+    },
+    // Mount a USB drive.
+    function() {
+      sendTestMessage({name: 'mountFakeUsbEmpty'}).then(this.next);
+    },
+    // Wait for the mount to appear.
+    function() {
+      remoteCall
+          .waitForElement(
+              appId, ['#directory-tree [volume-type-icon="removable"]'])
+          .then(this.next);
+    },
+    function() {
+      remoteCall.callRemoteTestUtil('getBreadcrumbPath', appId, [])
+          .then(this.next);
+    },
+    function(path) {
+      chrome.test.assertEq('/My files', path);
+      checkIfNoErrorsOccured(this.next);
+    },
+  ]);
+};