Bug 1837367 - Allow file migrators to show an error message if migration failed for some reason. r=kpatenio,desktop-theme-reviewers

The spec calls for a special-case in the event that file migration
ever fails - the wizard should be sent back to the selection page,
have the associated file migrator still set in the dropdown, and
show an error message.

A later patch in this series will add such an error message for
the bookmarks file migrator.

Depends on D180458

Differential Revision: https://phabricator.services.mozilla.com/D180490

browser/components/migration/tests/browser/browser_file_migration.js

@@ -62,6 +62,18 @@ class DummyFileMigrator extends FileMigratorBase {
   }
 }
 
+const { MockFilePicker } = SpecialPowers;
+
+add_setup(async () => {
+  // We use MockFilePicker to simulate a native file picker, and prepare it
+  // to return a dummy file pointed at TEST_FILE_PATH. The file at
+  // TEST_FILE_PATH is not required (nor expected) to exist.
+  MockFilePicker.init(window);
+  registerCleanupFunction(() => {
+    MockFilePicker.cleanup();
+  });
+});
+
 /**
  * Tests the flow of selecting a file migrator (in this case,
  * the DummyFileMigrator), getting the file picker opened for it,
@@ -97,15 +109,6 @@ add_task(async function test_file_migration() {
     return SUCCESS_STATE;
   });
 
-  // We use MockFilePicker to simulate a native file picker, and prepare it
-  // to return a dummy file pointed at TEST_FILE_PATH. The file at
-  // TEST_FILE_PATH is not required (nor expected) to exist.
-  const { MockFilePicker } = SpecialPowers;
-  MockFilePicker.init(window);
-  registerCleanupFunction(() => {
-    MockFilePicker.cleanup();
-  });
-
   let dummyFile = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
   dummyFile.initWithPath(TEST_FILE_PATH);
   let filePickerShownPromise = new Promise(resolve => {
@@ -182,4 +185,121 @@ add_task(async function test_file_migration() {
       }
     }
   });
+
+  sandbox.restore();
+});
+
+/**
+ * Tests that the migration wizard will go back to the selection page and
+ * show an error message if the migration for a FileMigrator throws an
+ * exception.
+ */
+add_task(async function test_file_migration_error() {
+  let migrator = new DummyFileMigrator();
+  let sandbox = sinon.createSandbox();
+  registerCleanupFunction(() => {
+    sandbox.restore();
+  });
+
+  // First, use Sinon to insert our DummyFileMigrator as the only available
+  // file migrator.
+  sandbox.stub(MigrationUtils, "getFileMigrator").callsFake(() => {
+    return migrator;
+  });
+  sandbox.stub(MigrationUtils, "availableFileMigrators").get(() => {
+    return [migrator];
+  });
+
+  const ERROR_MESSAGE = "This is my error message";
+
+  let migrateStub = sandbox.stub(migrator, "migrate").callsFake(() => {
+    throw new Error(ERROR_MESSAGE);
+  });
+
+  let dummyFile = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+  dummyFile.initWithPath(TEST_FILE_PATH);
+  let filePickerShownPromise = new Promise(resolve => {
+    MockFilePicker.showCallback = () => {
+      Assert.ok(true, "Filepicker shown.");
+      MockFilePicker.setFiles([dummyFile]);
+      resolve();
+    };
+  });
+  MockFilePicker.returnValue = MockFilePicker.returnOK;
+
+  await withMigrationWizardDialog(async prefsWin => {
+    let dialogBody = prefsWin.document.body;
+    let wizard = dialogBody.querySelector("migration-wizard");
+    let shadow = wizard.openOrClosedShadowRoot;
+
+    let wizardDone = BrowserTestUtils.waitForEvent(
+      wizard,
+      "MigrationWizard:DoneMigration"
+    );
+
+    // Now select our DummyFileMigrator from the list.
+    let selector = shadow.querySelector("#browser-profile-selector");
+    selector.click();
+
+    info("Waiting for panel-list shown");
+    await new Promise(resolve => {
+      wizard
+        .querySelector("panel-list")
+        .addEventListener("shown", resolve, { once: true });
+    });
+
+    info("Panel list shown. Clicking on panel-item");
+    let panelItem = wizard.querySelector(
+      `panel-item[key="${DUMMY_FILEMIGRATOR_KEY}"]`
+    );
+    panelItem.click();
+
+    // Selecting a file migrator from the selector should automatically
+    // open the file picker, so we await it here. Once the file is
+    // selected, migration should begin immediately.
+
+    info("Waiting for file picker");
+    await filePickerShownPromise;
+    await wizardDone;
+    Assert.ok(migrateStub.called, "Migrate on DummyFileMigrator was called.");
+
+    // At this point, with migration having completed, we should be showing
+    // the SELECTION page again with the ERROR_MESSAGE displayed.
+    let deck = shadow.querySelector("#wizard-deck");
+    await BrowserTestUtils.waitForMutationCondition(
+      deck,
+      { attributeFilter: ["selected-view"] },
+      () => {
+        return (
+          deck.getAttribute("selected-view") ==
+          "page-" + MigrationWizardConstants.PAGES.SELECTION
+        );
+      }
+    );
+
+    Assert.equal(
+      selector.selectedPanelItem.getAttribute("key"),
+      DUMMY_FILEMIGRATOR_KEY,
+      "Should have the file migrator selected."
+    );
+
+    let errorMessageContainer = shadow.querySelector(".file-import-error");
+
+    // Using BrowserTestUtils.is_visible to check for the visibility of the
+    // message seems to throw as it works its way up the ancestry and hits
+    // the shadowRoot. We'll work around this by making sure that the
+    // boundingClientRect has a width and height.
+    let errorRect = errorMessageContainer.getBoundingClientRect();
+    Assert.ok(
+      errorRect.width && errorRect.height,
+      "Should be showing the error message container"
+    );
+
+    let fileImportErrorMessage = shadow.querySelector(
+      "#file-import-error-message"
+    ).textContent;
+    Assert.equal(fileImportErrorMessage, ERROR_MESSAGE);
+  });
+
+  sandbox.restore();
 });

browser/components/migration/tests/chrome/test_migration_wizard.html

@@ -1139,6 +1139,60 @@
           ""
         );
       });
+
+      /**
+       * Tests that the migration wizard can be put into the selection page after
+       * a file migrator error and show an error message.
+       */
+      add_task(async function test_file_migrator_error() {
+        const FILE_MIGRATOR_KEY = "some-file-migrator";
+        const FILE_IMPORT_ERROR_MESSAGE = "This is an error message";
+        const MIGRATORS = [
+          {
+            key: "some-browser-0",
+            type: MigrationWizardConstants.MIGRATOR_TYPES.BROWSER,
+            displayName: "Some Browser 0",
+            resourceTypes: ["HISTORY", "FORMDATA", "PASSWORDS", "BOOKMARKS"],
+            profile: { id: "person-2", name: "Person 2" },
+          },
+          {
+            key: "some-browser-1",
+            type: MigrationWizardConstants.MIGRATOR_TYPES.BROWSER,
+            displayName: "Some Browser 1",
+            resourceTypes: ["HISTORY", "BOOKMARKS"],
+            profile: null,
+          },
+          {
+            key: FILE_MIGRATOR_KEY,
+            type: MigrationWizardConstants.MIGRATOR_TYPES.FILE,
+            displayName: "Some File Migrator",
+            resourceTypes: [],
+          },
+        ];
+
+        gWiz.setState({
+          page: MigrationWizardConstants.PAGES.SELECTION,
+          migrators: MIGRATORS,
+          showImportAll: true,
+          migratorKey: "some-file-migrator",
+          fileImportErrorMessage: FILE_IMPORT_ERROR_MESSAGE,
+        });
+
+        let errorMessageContainer = gShadowRoot.querySelector(".file-import-error");
+        ok(!isHidden(errorMessageContainer), "Error message should be shown.");
+        let errorText = gShadowRoot.querySelector("#file-import-error-message").textContent;
+        is(errorText, FILE_IMPORT_ERROR_MESSAGE);
+
+        gWiz.setState({
+          page: MigrationWizardConstants.PAGES.SELECTION,
+          migrators: MIGRATORS,
+          showImportAll: true,
+        });
+
+        ok(isHidden(errorMessageContainer), "Error message should be hidden.");
+        errorText = gShadowRoot.querySelector("#file-import-error-message").textContent;
+        is(errorText, "");
+      });
     </script>
   </head>
   <body>