[Cosmos] Return undefined for sum aggregate when one partition is undefined

sdk/cosmosdb/cosmos/CHANGELOG.md

@@ -1,5 +1,9 @@
 # Release History
 
+## 3.9.4 (2021-01-04)
+
+- BUGFIX: Sums group by operations for cross-partition queries correctly with null values
+
 ## 3.9.3 (2020-10-19)
 
 - BUGFIX: Fixes bulk operations with top level partitionKey values that are undefined or null.

sdk/cosmosdb/cosmos/src/queryExecutionContext/EndpointComponent/GroupByValueEndpointComponent.ts

@@ -66,6 +66,10 @@ export class GroupByValueEndpointComponent implements ExecutionContext {
 
         if (this.aggregateType) {
           const aggregateResult = extractAggregateResult(payload[0]);
+          // if aggregate result is null, we need to short circuit aggregation and return undefined
+          if (aggregateResult === null) {
+            this.completed = true;
+          }
           this.aggregators.get(grouping).aggregate(aggregateResult);
         } else {
           // Queries with no aggregates pass the payload directly to the aggregator
@@ -75,7 +79,11 @@ export class GroupByValueEndpointComponent implements ExecutionContext {
       }
     }
 
-    // It no results are left in the underling execution context, convert our aggregate results to an array
+    // We bail early since we got an undefined result back `[{}]`
+    if (this.completed) {
+      return { result: undefined, headers: aggregateHeaders };
+    }
+    // If no results are left in the underlying execution context, convert our aggregate results to an array
     for (const aggregator of this.aggregators.values()) {
       this.aggregateResultArray.push(aggregator.getResult());
     }

sdk/cosmosdb/cosmos/src/queryExecutionContext/EndpointComponent/emptyGroup.ts

@@ -8,4 +8,4 @@ export const emptyGroup = "__empty__";
 // Newer API versions rewrite the query to return `item2`. It fixes some legacy issues with the original `item` result
 // Aggregator code should use item2 when available
 export const extractAggregateResult = (payload: any) =>
-  payload.item2 ? payload.item2 : payload.item;
+  Object.keys(payload).length > 0 ? (payload.item2 ? payload.item2 : payload.item) : null;

sdk/cosmosdb/cosmos/test/public/functional/query.spec.ts

@@ -124,5 +124,91 @@ describe("Queries", function() {
         "second batch element should be doc3"
       );
     });
+
+    describe("SUM query iterator", function() {
+      this.timeout(process.env.MOCHA_TIMEOUT || 30000);
+
+      it("returns undefined sum with null value in aggregator", async function() {
+        const container = await getTestContainer(
+          "Validate QueryIterator Functionality",
+          undefined,
+          {
+            throughput: 10100,
+            partitionKey: "/id"
+          }
+        );
+        await container.items.create({ id: "5eded6f8asdfasdfasdfaa21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5eded6f8a21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5edasdfasdfed6f8a21be0109ae34e29", age: null });
+        await container.items.create({ id: "5eded6f8a2dd1be0109ae34e29", age: 22 });
+        await container.items.create({ id: "AndersenFamily" });
+        await container.items.create({ id: "1" });
+
+        const queryIterator = container.items.query("SELECT VALUE SUM(c.age) FROM c");
+        const { resources: sum } = await queryIterator.fetchAll();
+        assert.equal(sum.length, 0);
+      });
+      it("returns undefined sum with false value in aggregator", async function() {
+        const container = await getTestContainer(
+          "Validate QueryIterator Functionality",
+          undefined,
+          {
+            throughput: 10100,
+            partitionKey: "/id"
+          }
+        );
+        await container.items.create({ id: "5eded6f8asdfasdfasdfaa21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5eded6f8a21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5edasdfasdfed6f8a21be0109ae34e29", age: false });
+        await container.items.create({ id: "5eded6f8a2dd1be0109ae34e29", age: 22 });
+        await container.items.create({ id: "AndersenFamily" });
+        await container.items.create({ id: "1" });
+
+        const queryIterator = container.items.query("SELECT VALUE SUM(c.age) FROM c");
+        const { resources: sum } = await queryIterator.fetchAll();
+        assert.equal(sum.length, 0);
+      });
+      it("returns undefined sum with empty array value in aggregator", async function() {
+        const container = await getTestContainer(
+          "Validate QueryIterator Functionality",
+          undefined,
+          {
+            throughput: 10100,
+            partitionKey: "/id"
+          }
+        );
+        await container.items.create({ id: "5eded6f8asdfasdfasdfaa21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5eded6f8a21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5edasdfasdfed6f8a21be0109ae34e29", age: [] });
+        await container.items.create({ id: "5eded6f8a2dd1be0109ae34e29", age: 22 });
+        await container.items.create({ id: "AndersenFamily" });
+        await container.items.create({ id: "1" });
+
+        const queryIterator = container.items.query("SELECT VALUE SUM(c.age) FROM c");
+        const { resources: sum } = await queryIterator.fetchAll();
+        assert.equal(sum.length, 0);
+      });
+      it("returns a valid sum with undefined value in aggregator", async function() {
+        const container = await getTestContainer(
+          "Validate QueryIterator Functionality",
+          undefined,
+          {
+            throughput: 10100,
+            partitionKey: "/id"
+          }
+        );
+        await container.items.create({ id: "5eded6f8asdfasdfasdfaa21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5eded6f8a21be0109ae34e29", age: 22 });
+        await container.items.create({ id: "5edasdfasdfed6f8a21be0109ae34e29", age: undefined });
+        await container.items.create({ id: "5eded6f8a2dd1be0109ae34e29", age: 22 });
+        await container.items.create({ id: "AndersenFamily" });
+        await container.items.create({ id: "1" });
+
+        const queryIterator = container.items.query("SELECT VALUE SUM(c.age) FROM c");
+        const { resources: sum } = await queryIterator.fetchAll();
+        assert.equal(sum.length, 1);
+        assert.equal(sum[0], 66);
+      });
+    });
   });
 });