Check if SCB file exists on external storage before reading

Author: tanx

src/action/file-mobile.js

@@ -103,6 +103,8 @@ class FileAction {
   }
 
   async readSCBFromExternalStorage() {
+    const exists = await this._FS.exists(this.scbExternalPath);
+    if (!exists) return;
     return this._FS.readFile(this.scbExternalPath, 'base64');
   }
 }

test/unit/action/file-mobile.spec.js

@@ -132,8 +132,14 @@ describe('Action File Mobile Unit Tests', () => {
   });
 
   describe('get readSCBFromExternalStorage()', () => {
-    it('should get lnd directory', async () => {
+    it('should read the scb if it exists', async () => {
+      RNFS.exists.resolves(true);
       expect(await file.readSCBFromExternalStorage(), 'to equal', 'some-data');
     });
+
+    it('should not read the scb if it does not exist', async () => {
+      RNFS.exists.resolves(false);
+      expect(await file.readSCBFromExternalStorage(), 'to equal', undefined);
+    });
   });
 });