fix(data-point-service): resetCache should clear stale data (#494)

* fix(data-point-service): resetCache should clear stale data

resetCache doesn't remove stale data so, it happens that for removed contents it still provide old
data. Implemented the clear of stale data on promise chain when the clear cache parameter is applied

fix #492

.all-contributorsrc

@@ -107,6 +107,17 @@
         "question",
         "code"
       ]
+    },
+    {
+      "login": "schiavig",
+      "name": "Giampiero Schiavi",
+      "avatar_url": "https://avatars.githubusercontent.com/u/85735845?v=4",
+      "profile": "https://github.com/schiavig",
+      "contributions": [
+        "code",
+        "test",
+        "bug"
+      ]
     }
   ],
   "repoType": "github"

packages/data-point-service/lib/cache-middleware.js

@@ -243,6 +243,10 @@ function before(service, ctx, next) {
   const cache = EntityCacheParams.getCacheParams(ctx.context.params);
 
   if (!cache.ttl || ctx.locals.resetCache === true) {
+    if (ctx.locals.resetCache === true) {
+      const currentEntryKey = module.exports.generateKey(cache.cacheKey, ctx);
+      RedisController.deleteSWRStaleEntry(service, currentEntryKey);
+    }
     next();
     return false;
   }

packages/data-point-service/lib/cache-middleware.test.js

@@ -549,6 +549,10 @@ describe("before", () => {
       .spyOn(RedisController, "getEntry")
       .mockReturnValue("noTTLEntry");
 
+    mocks.deleteSWRStaleEntry = jest
+      .spyOn(RedisController, "deleteSWRStaleEntry")
+      .mockReturnValue(Promise.resolve());
+
     return mocks;
   }
 
@@ -564,14 +568,15 @@ describe("before", () => {
       expect(result).toEqual(false);
       expect(mocks.next).toBeCalledWith();
     });
-    it("should call next and return false if resetCache is true", () => {
+    it("should delete stale and call next returning false if resetCache is true", () => {
       const mocks = createMocks();
       mocks.ctx.locals.resetCache = true;
       const result = CacheMiddleware.before(
         mocks.service,
         mocks.ctx,
         mocks.next
       );
+      expect(mocks.deleteSWRStaleEntry).toBeCalled();
       expect(result).toEqual(false);
       expect(mocks.next).toBeCalledWith();
     });

packages/data-point-service/lib/redis-controller.js

@@ -93,11 +93,23 @@ function deleteSWRControlEntry(service, key) {
   return deleteEntry(service, createSWRControlKey(key));
 }
 
+/**
+ * Delete stale entry by key
+ * @param {Service} service Service instance
+ * @param {String} key entry key
+ * @returns {Promise}
+ */
+function deleteSWRStaleEntry(service, key) {
+  const staleKey = createSWRStaleKey(key);
+  return deleteEntry(service, staleKey);
+}
+
 module.exports = {
   createSWRControlKey,
   createSWRStaleKey,
   deleteEntry,
   deleteSWRControlEntry,
+  deleteSWRStaleEntry,
   getEntry,
   getSWRControlEntry,
   getSWRStaleEntry,

packages/data-point-service/lib/redis-controller.test.js

@@ -147,3 +147,15 @@ describe("deleteSWRControlEntry", () => {
     expect(service.cache.del).toBeCalledWith("key:swr.control");
   });
 });
+
+describe("deleteSWRStaleEntry", () => {
+  it("should delete a stale entry", () => {
+    const service = {
+      cache: {
+        del: jest.fn()
+      }
+    };
+    RedisController.deleteSWRStaleEntry(service, "key");
+    expect(service.cache.del).toBeCalledWith("key:swr.stale");
+  });
+});