feat(suite-native): enhance BIP329 export handling for cancelled directory picker

Author: jbazant

suite-native/bip329/jest.config.js

@@ -0,0 +1,11 @@
+/**
+ * Jest configuration for native packages.
+ * Keeping this file next to the package.json file instead of providing configuration
+ * with `-c ../../jest.config.native` option in package.json scripts
+ * allows us to run jest tests directly from IDEs.
+ */
+const baseConfig = require('../../jest.config.native');
+
+module.exports = {
+    ...baseConfig,
+};

suite-native/bip329/package.json

@@ -8,7 +8,9 @@
     "scripts": {
         "depcheck": "yarn g:depcheck",
         "type-check": "yarn g:tsc --build",
-        "lint:js": "yarn g:eslint '**/*.{ts,tsx,js}'"
+        "lint:js": "yarn g:eslint '**/*.{ts,tsx,js}'",
+        "test:unit": "yarn g:jest:native",
+        "test:unit:watch": "yarn g:jest --watch"
     },
     "dependencies": {
         "@suite-common/bip329": "workspace:*",

suite-native/bip329/src/Bip329ExportButton.tsx

@@ -54,6 +54,9 @@ export const Bip329ExportButton = ({
         }
 
         switch (result.reason) {
+            case 'cancelled':
+                // User dismissed the directory picker; nothing to report.
+                return;
             case 'exportFailed':
                 showToast({
                     intent: 'critical',

suite-native/bip329/src/exportBip329.test.ts

@@ -0,0 +1,114 @@
+import { Platform } from 'react-native';
+
+import { Directory } from 'expo-file-system';
+import * as Sharing from 'expo-sharing';
+
+import { type AllLabelsForAccount } from '@suite-common/suite-sync';
+
+import { exportBip329 } from './exportBip329';
+
+const mockDirectoryWrite = jest.fn();
+const mockCreateFile = jest.fn(() => ({ write: mockDirectoryWrite }));
+
+jest.mock('expo-file-system', () => ({
+    File: jest.fn().mockImplementation(() => ({
+        exists: false,
+        create: jest.fn(),
+        write: jest.fn(),
+        uri: 'file:///cache/account_labels.jsonl',
+    })),
+    Paths: { cache: 'file:///cache' },
+    Directory: {
+        pickDirectoryAsync: jest.fn(),
+    },
+}));
+
+jest.mock('expo-sharing', () => ({
+    shareAsync: jest.fn(),
+}));
+
+const mockPickDirectoryAsync = jest.mocked(Directory.pickDirectoryAsync);
+const mockShareAsync = jest.mocked(Sharing.shareAsync);
+
+const originalPlatformOS = Platform.OS;
+const setPlatformOS = (os: typeof Platform.OS) => {
+    Platform.OS = os;
+};
+
+const LABELS: AllLabelsForAccount = { accountLabel: null, addressLabels: [], outputLabels: [] };
+
+describe('exportBip329', () => {
+    beforeEach(() => {
+        jest.clearAllMocks();
+    });
+
+    afterAll(() => {
+        setPlatformOS(originalPlatformOS);
+    });
+
+    describe('on android', () => {
+        beforeEach(() => {
+            setPlatformOS('android');
+        });
+
+        it('writes the file into the picked directory and returns success', async () => {
+            mockPickDirectoryAsync.mockResolvedValue({ createFile: mockCreateFile } as never);
+
+            const result = await exportBip329(null, LABELS);
+
+            expect(result).toEqual({ success: true });
+            expect(mockCreateFile).toHaveBeenCalledTimes(1);
+            expect(mockDirectoryWrite).toHaveBeenCalledTimes(1);
+        });
+
+        it('returns the cancelled reason when the user dismisses the directory picker', async () => {
+            mockPickDirectoryAsync.mockRejectedValue(
+                Object.assign(new Error('The file picker was cancelled by the user'), {
+                    code: 'ERR_PICKER_CANCELLED',
+                }),
+            );
+
+            const result = await exportBip329(null, LABELS);
+
+            expect(result).toEqual({ success: false, reason: 'cancelled' });
+        });
+
+        it('returns the exportFailed reason for any other picker error', async () => {
+            mockPickDirectoryAsync.mockRejectedValue(new Error('boom'));
+
+            const result = await exportBip329(null, LABELS);
+
+            expect(result).toEqual({ success: false, reason: 'exportFailed' });
+        });
+    });
+
+    describe('on ios', () => {
+        beforeEach(() => {
+            setPlatformOS('ios');
+        });
+
+        it('shares the cached file and returns success', async () => {
+            mockShareAsync.mockResolvedValue(undefined);
+
+            const result = await exportBip329(null, LABELS);
+
+            expect(result).toEqual({ success: true });
+            expect(mockShareAsync).toHaveBeenCalledWith(
+                'file:///cache/account_labels.jsonl',
+                expect.objectContaining({ UTI: 'public.jsonl' }),
+            );
+        });
+    });
+
+    describe('on an unsupported platform', () => {
+        beforeEach(() => {
+            setPlatformOS('web');
+        });
+
+        it('returns the fileSavingNotSupported reason', async () => {
+            const result = await exportBip329(null, LABELS);
+
+            expect(result).toEqual({ success: false, reason: 'fileSavingNotSupported' });
+        });
+    });
+});

suite-native/bip329/src/exportBip329.ts

@@ -9,7 +9,9 @@ import { sanitizeFilename } from '@trezor/utils';
 
 type ExportBip329Result =
     | { success: true }
-    | { success: false; reason: 'fileSavingNotSupported' | 'exportFailed' };
+    | { success: false; reason: 'fileSavingNotSupported' | 'exportFailed' | 'cancelled' };
+
+const PICKER_CANCELLED_ERROR_CODE = 'ERR_PICKER_CANCELLED';
 
 const createJsonlContent = (labels: AllLabelsForAccount): string => {
     const labelsToExport = suiteSyncToBip329({
@@ -39,7 +41,6 @@ const saveFile = async (fileName: string, content: string): Promise<void> => {
         newFile.write(content);
     } else if (Platform.OS === 'ios') {
         await Sharing.shareAsync(cachedFile.uri, {
-            mimeType: 'application/jsonl',
             UTI: 'public.jsonl',
         });
     } else {
@@ -61,6 +62,10 @@ export const exportBip329 = async (
             return { success: false, reason: 'fileSavingNotSupported' };
         }
 
+        if (error?.code === PICKER_CANCELLED_ERROR_CODE) {
+            return { success: false, reason: 'cancelled' };
+        }
+
         return { success: false, reason: 'exportFailed' };
     }