diff --git a/src/test/storage-provider-test.js b/src/test/storage-provider-test.js
index 477f89529..fa8b14f99 100644
--- a/src/test/storage-provider-test.js
+++ b/src/test/storage-provider-test.js
@@ -33,7 +33,8 @@ describe('Storage', function () {
         const gBackupConfig = {
             key: 'key',
             backupDir: null,
-            prefix: 'someprefix'
+            prefix: 'someprefix',
+            _provider: 'filesystem' // need this internal variable since we call the backend logic directly for testing
         };
 
         let defaultBackupSite;
diff --git a/src/test/syncer-test.js b/src/test/syncer-test.js
index c8db84b7a..ab1f62df3 100644
--- a/src/test/syncer-test.js
+++ b/src/test/syncer-test.js
@@ -25,10 +25,39 @@ describe('Syncer', function () {
 
     async function getChanges(dataLayout) {
         const { delQueue, addQueue, integrityMap } = await syncer.sync(dataLayout, gCacheFile);
+        // inject fake integrity information
+        for (const change of addQueue) {
+            integrityMap.set(change.path, { size: 42, sha256: 'fake-sha256' });
+        }
         await syncer.finalize(integrityMap, gCacheFile);
         return delQueue.concat(addQueue);
     }
 
+    function checkCache(cacheFile, changes) {
+        // store cache file indexed by path
+        const data = fs.readFileSync(cacheFile, 'utf8');
+        const pathMap = new Map();
+        if (data.length !== 0) {
+            const lines = data.trim().split('\n');
+            for (const line of lines) {
+                const entry = JSON.parse(line);
+                pathMap.set(entry.path, entry);
+            }
+        }
+
+        // for every 'add' operation, there must be an entry in the cache file with integrity
+        // for every 'delete' operation, there must be no entry in the cache file
+        for (const change of changes) {
+            if (change.operation === 'add') {
+                expect(pathMap.get(change.path).integrity.sha256).to.be('fake-sha256');
+                expect(pathMap.get(change.path).stat).to.be.an('object');
+            } else if (change.operation === 'remove') {
+                // if a file was removed, it won't be in pathMap. but if the file became a dir, it can be in pathMap without integrity info
+                expect(!pathMap.has(change.path) || !pathMap.get(change.path).integrity).to.be(true);
+            }
+        }
+    }
+
     it('missing cache - removes remote dir', async function () {
         safe.fs.unlinkSync(gCacheFile);
         createTree(gTmpDir, { });
@@ -36,6 +65,8 @@ describe('Syncer', function () {
         const dataLayout = new DataLayout(gTmpDir, []);
         const changes = await getChanges(dataLayout);
         expect(changes).to.eql([{ operation: 'removedir', path: '', reason: 'nocache' }]);
+
+        expect(fs.readFileSync(gCacheFile, 'utf8')).to.be('');
     });
 
     it('empty cache - adds all', async function () {
@@ -50,6 +81,8 @@ describe('Syncer', function () {
             { operation: 'add', path: 'test/test.js', reason: 'new', position: 1 },
             { operation: 'add', path: 'walrus', reason: 'new', position: 2 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('empty cache - deep', async function () {
@@ -62,6 +95,8 @@ describe('Syncer', function () {
         expect(changes).to.eql([
             { operation: 'add', path: 'a/b/c/d/e', reason: 'new', position: 0 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('ignores special files', async function () {
@@ -74,6 +109,8 @@ describe('Syncer', function () {
         expect(changes).to.eql([
             { operation: 'add', path: 'readme', reason: 'new', position: 0 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('adds changed files', async function () {
@@ -93,6 +130,8 @@ describe('Syncer', function () {
             { operation: 'add', path: 'src/index.js', reason: 'changed', position: 0 },
             { operation: 'add', path: 'test/test.js', reason: 'changed', position: 1 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('removes missing files', async function () {
@@ -112,6 +151,8 @@ describe('Syncer', function () {
             { operation: 'remove', path: 'src/index.js', reason: 'missing' },
             { operation: 'remove', path: 'walrus', reason: 'missing' }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('removes missing dirs', async function () {
@@ -131,6 +172,8 @@ describe('Syncer', function () {
             { operation: 'removedir', path: 'src', reason: 'missing' },
             { operation: 'removedir', path: 'test', reason: 'missing' }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('all files disappeared', async function () {
@@ -151,6 +194,8 @@ describe('Syncer', function () {
             { operation: 'removedir', path: 'test', reason: 'missing' },
             { operation: 'remove', path: 'walrus', reason: 'missing' }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('no redundant deletes', async function () {
@@ -170,6 +215,8 @@ describe('Syncer', function () {
             { operation: 'removedir', path: 'a/b', reason: 'missing' },
             { operation: 'add', path: 'a/f', reason: 'new', position: 0 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('file became dir', async function () {
@@ -189,6 +236,8 @@ describe('Syncer', function () {
             { operation: 'remove', path: 'data/test/test.js', reason: 'wasfile' },
             { operation: 'add', path: 'data/test/test.js/trick', reason: 'new', position: 0 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('dir became file', async function () {
@@ -208,6 +257,8 @@ describe('Syncer', function () {
             { operation: 'removedir', path: 'test', reason: 'wasdir' },
             { operation: 'add', path: 'test', reason: 'wasdir', position: 0 }
         ]);
+
+        checkCache(gCacheFile, changes);
     });
 
     it('is complicated', async function () {
@@ -260,5 +311,7 @@ describe('Syncer', function () {
         changes = await getChanges(dataLayout);
 
         expect(changes.length).to.be(0);
+
+        checkCache(gCacheFile, changes);
     });
 });