Fix deduplicator

CHANGELOG.md

@@ -3,7 +3,8 @@
 Expect active development and potentially significant breaking changes in the `0.x` track. We'll try to be diligent about releasing a `1.0` version in a timely fashion (ideally within 3 to 6 months), to signal the start of a more stable API.
 
 ### vNEXT
-- Fix `cachePolicy: cache-and-network` queries never dispatching `APOLLO_QUERY_RESULT_CLIENT` [PR #1463](https://github.com/apollographql/apollo-client/pull/1463)
+- Fix: `cachePolicy: cache-and-network` queries now dispatch `APOLLO_QUERY_RESULT_CLIENT` [PR #1463](https://github.com/apollographql/apollo-client/pull/1463)
+- Fix: query deduplication no longer causes query errors to prevent subsequent successful execution of the same query  [PR #1481](https://github.com/apollographql/apollo-client/pull/1481)
 
 
 ### 1.0.0-rc.6

src/transport/Deduplicator.ts

@@ -32,6 +32,10 @@ export class Deduplicator {
     .then( res => {
       delete this.inFlightRequestPromises[key];
       return res;
+    })
+    .catch( err => {
+        delete this.inFlightRequestPromises[key];
+        throw err;
     });
   }
 

test/deduplicator.ts

@@ -45,6 +45,47 @@ describe('query deduplication', () => {
 
   });
 
+  it(`will not deduplicate requests following an errored query`, () => {
+
+    const document: DocumentNode = gql`query test1($x: String){
+      test(x: $x)
+    }`;
+    const variables = { x: 'Hello World' };
+
+    const request: Request = {
+      query: document,
+      variables: variables,
+      operationName: getOperationName(document),
+    };
+
+    let called = 0;
+    const deduper = new Deduplicator({
+      query: () => {
+        called += 1;
+        switch (called) {
+          case 1:
+            return new Promise((resolve, reject) => {
+              setTimeout(reject);
+            });
+          case 2:
+            return new Promise((resolve, reject) => {
+              setTimeout(resolve);
+            });
+          default:
+            return assert(false, 'Should not have been called more than twice');
+        }
+
+      },
+    } as any );
+
+    return deduper.query(request)
+    .catch( () => {
+      deduper.query(request);
+      return assert.equal(called, 2);
+    });
+
+  });
+
   it(`deduplicates identical queries`, () => {
 
     const document: DocumentNode = gql`query test1($x: String){

test/fetchMore.ts

@@ -52,7 +52,7 @@ describe('updateQuery on a simple query', () => {
       },
     });
 
-    return new Promise((resolve) => setTimeout(resolve))
+    return new Promise((resolve) => setTimeout(resolve, 5))
       .then(() => obsHandle)
       .then((watchedQuery: ObservableQuery<any>) => {
         assert.equal(latestResult.data.entry.value, 1);
@@ -119,7 +119,7 @@ describe('updateQuery on a query with required and optional variables', () => {
       },
     });
 
-    return new Promise((resolve) => setTimeout(resolve))
+    return new Promise((resolve) => setTimeout(resolve, 5))
         .then(() => obsHandle)
         .then((watchedQuery: ObservableQuery<any>) => {
           assert.equal(latestResult.data.entry.value, 1);