SERVER-24769 Add support for $lookup and $graphLookup on a view.

1 files changed, 93 insertions, 1 deletions

diff --git a/jstests/views/views_aggregation.js b/jstests/views/views_aggregation.js
index a6281f5bc94..87cf3d7908e 100644
--- a/jstests/views/views_aggregation.js
+++ b/jstests/views/views_aggregation.js
@@ -2,7 +2,7 @@
 (function() {
     "use strict";
 
-    // For arrayEq and orderedArrayEq.
+    // For arrayEq, assertErrorCode, and orderedArrayEq.
     load("jstests/aggregation/extras/utils.js");
 
     let viewsDB = db.getSiblingDB("views_aggregation");
@@ -68,4 +68,96 @@
     const doOrderedSort = true;
     assertAggResultEq("popSortedView", [], allDocuments.sort(byPopulation), doOrderedSort);
     assertAggResultEq("popSortedView", [{$limit: 1}, {$project: {_id: 1}}], [{_id: "Palo Alto"}]);
+
+    // Test that the $out stage errors when given a view namespace.
+    assertErrorCode(coll, [{$out: "emptyPipelineView"}], 18631);
+
+    // Test that the $lookup stage resolves the view namespace referenced in the 'from' field.
+    assertAggResultEq(
+        coll.getName(),
+        [
+          {$match: {_id: "New York"}},
+          {$lookup: {from: "identityView", localField: "_id", foreignField: "_id", as: "matched"}},
+          {$unwind: "$matched"},
+          {$project: {_id: 1, matchedId: "$matched._id"}}
+        ],
+        [{_id: "New York", matchedId: "New York"}]);
+
+    // Test that the $graphLookup stage resolves the view namespace referenced in the 'from' field.
+    assertAggResultEq(coll.getName(),
+                      [
+                        {$match: {_id: "New York"}},
+                        {
+                          $graphLookup: {
+                              from: "identityView",
+                              startWith: "$_id",
+                              connectFromField: "_id",
+                              connectToField: "_id",
+                              as: "matched"
+                          }
+                        },
+                        {$unwind: "$matched"},
+                        {$project: {_id: 1, matchedId: "$matched._id"}}
+                      ],
+                      [{_id: "New York", matchedId: "New York"}]);
+
+    // Test that the $lookup stage resolves the view namespace referenced in the 'from' field of
+    // another $lookup stage nested inside of it.
+    assert.commandWorked(viewsDB.runCommand({
+        create: "viewWithLookupInside",
+        viewOn: coll.getName(),
+        pipeline: [
+            {
+              $lookup:
+                  {from: "identityView", localField: "_id", foreignField: "_id", as: "matched"}
+            },
+            {$unwind: "$matched"},
+            {$project: {_id: 1, matchedId: "$matched._id"}}
+        ]
+    }));
+
+    assertAggResultEq(
+        coll.getName(),
+        [
+          {$match: {_id: "New York"}},
+          {
+            $lookup: {
+                from: "viewWithLookupInside",
+                localField: "_id",
+                foreignField: "matchedId",
+                as: "matched"
+            }
+          },
+          {$unwind: "$matched"},
+          {$project: {_id: 1, matchedId1: "$matched._id", matchedId2: "$matched.matchedId"}}
+        ],
+        [{_id: "New York", matchedId1: "New York", matchedId2: "New York"}]);
+
+    // Test that the $graphLookup stage resolves the view namespace referenced in the 'from' field
+    // of a $lookup stage nested inside of it.
+    let graphLookupPipeline = [
+        {$match: {_id: "New York"}},
+        {
+          $graphLookup: {
+              from: "viewWithLookupInside",
+              startWith: "$_id",
+              connectFromField: "_id",
+              connectToField: "matchedId",
+              as: "matched"
+          }
+        },
+        {$unwind: "$matched"},
+        {$project: {_id: 1, matchedId1: "$matched._id", matchedId2: "$matched.matchedId"}}
+    ];
+
+    assertAggResultEq(coll.getName(),
+                      graphLookupPipeline,
+                      [{_id: "New York", matchedId1: "New York", matchedId2: "New York"}]);
+
+    // Test that the $facet stage resolves the view namespace referenced in the 'from' field of a
+    // $lookup stage nested inside of a $graphLookup stage.
+    assertAggResultEq(
+        coll.getName(),
+        [{$facet: {nested: graphLookupPipeline}}],
+        [{nested: [{_id: "New York", matchedId1: "New York", matchedId2: "New York"}]}]);
 }());