Repository: ViacomInc/data-point (js)

Issue:
staleWhileRevalidate is not saving new value
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**Problem description**:

When revalidation is done the new value is not getting saved, this is because of recent changes done in data point to return value instead of accumulator were not reflected on the data-point-service logic where:

1. we call `resolveFromAccumulator`:

https://github.com/ViacomInc/data-point/blob/2df6ae81fcee353ffbfdf207766ff56745a375b9/packages/data-point-service/lib/cache-middleware.js#L114-L119

2. then we pass the result to:

https://github.com/ViacomInc/data-point/blob/2df6ae81fcee353ffbfdf207766ff56745a375b9/packages/data-point-service/lib/cache-middleware.js#L44-L52

Line 48 should had been the value itself, not an accumulator. 

**Suggested solution**:

replace `acc` by a `value` which we pass to `addEntry` as is.

update tests.

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REPORTING BUG:

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**What happened**:

When revalidating via `staleWhileRevalidate` revalidation value gets saved as undefined.

**Reproduction**: 

happens on any instance of `staleWhileRevalidate`


Pull request:
fix(data-point-service): pass value to addEntry when revalidating
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**What**:

closes #437

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Patch:
diff --git a/packages/data-point-service/lib/cache-middleware.js b/packages/data-point-service/lib/cache-middleware.js
index 5c999a8..f403e1c 100644
--- a/packages/data-point-service/lib/cache-middleware.js
+++ b/packages/data-point-service/lib/cache-middleware.js
@@ -45,9 +45,9 @@ function updateSWREntry(service, entryKey, cache) {
   /**
    * @param {Accumulator} acc
    */
-  return acc => {
+  return value => {
     debug("Updating cache key: %s with new stale value", entryKey);
-    return service.staleWhileRevalidate.addEntry(entryKey, acc.value, cache);
+    return service.staleWhileRevalidate.addEntry(entryKey, value, cache);
   };
 }
 


Test patch:
diff --git a/packages/data-point-service/lib/cache-middleware.test.js b/packages/data-point-service/lib/cache-middleware.test.js
index 59bec83..acf59a0 100644
--- a/packages/data-point-service/lib/cache-middleware.test.js
+++ b/packages/data-point-service/lib/cache-middleware.test.js
@@ -89,8 +89,8 @@ describe("updateSWREntry", () => {
   it("should add stale entry", () => {
     const mockAddEntry = jest.fn();
     const service = _.set({}, "staleWhileRevalidate.addEntry", mockAddEntry);
-    const acc = _.set({}, "value", "value");
-    CacheMiddleware.updateSWREntry(service, "entryKey", "cache")(acc);
+    const value = "value";
+    CacheMiddleware.updateSWREntry(service, "entryKey", "cache")(value);
     expect(mockAddEntry).toBeCalledWith("entryKey", "value", "cache");
     expect(mockDebug.mock.calls).toMatchSnapshot();
   });