DRIVERS-776: Split tests to work around SERVER-57403 (#1013)

Author: jmikola

source/crud/tests/unified/aggregate-let.json

@@ -44,6 +44,109 @@
           "minServerVersion": "5.0"
         }
       ],
+      "operations": [
+        {
+          "name": "aggregate",
+          "object": "collection0",
+          "arguments": {
+            "pipeline": [
+              {
+                "$match": {
+                  "$expr": {
+                    "$eq": [
+                      "$_id",
+                      "$$id"
+                    ]
+                  }
+                }
+              },
+              {
+                "$project": {
+                  "_id": 0,
+                  "x": "$$x",
+                  "y": "$$y",
+                  "rand": "$$rand"
+                }
+              }
+            ],
+            "let": {
+              "id": 1,
+              "x": "foo",
+              "y": {
+                "$literal": "bar"
+              },
+              "rand": {
+                "$rand": {}
+              }
+            }
+          },
+          "expectResult": [
+            {
+              "x": "foo",
+              "y": "bar",
+              "rand": {
+                "$$type": "double"
+              }
+            }
+          ]
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client0",
+          "events": [
+            {
+              "commandStartedEvent": {
+                "command": {
+                  "aggregate": "coll0",
+                  "pipeline": [
+                    {
+                      "$match": {
+                        "$expr": {
+                          "$eq": [
+                            "$_id",
+                            "$$id"
+                          ]
+                        }
+                      }
+                    },
+                    {
+                      "$project": {
+                        "_id": 0,
+                        "x": "$$x",
+                        "y": "$$y",
+                        "rand": "$$rand"
+                      }
+                    }
+                  ],
+                  "let": {
+                    "id": 1,
+                    "x": "foo",
+                    "y": {
+                      "$literal": "bar"
+                    },
+                    "rand": {
+                      "$rand": {}
+                    }
+                  }
+                }
+              }
+            }
+          ]
+        }
+      ]
+    },
+    {
+      "description": "Aggregate with let option and dollar-prefixed $literal value",
+      "runOnRequirements": [
+        {
+          "minServerVersion": "5.0",
+          "topologies": [
+            "single",
+            "replicaset"
+          ]
+        }
+      ],
       "operations": [
         {
           "name": "aggregate",

source/crud/tests/unified/aggregate-let.yml

@@ -22,9 +22,45 @@ initialData: &initialData
       - { _id: 1 }
 
 tests:
+  # TODO: Once SERVER-57403 is resolved, this test can be removed in favor of
+  # the "dollar-prefixed $literal value" test below.
   - description: "Aggregate with let option"
     runOnRequirements:
       - minServerVersion: "5.0"
+    operations:
+      - name: aggregate
+        object: *collection0
+        arguments:
+          pipeline: &pipeline0
+            # $match takes a query expression, so $expr is necessary to utilize
+            # an aggregate expression context and access "let" variables.
+            - $match: { $expr: { $eq: ["$_id", "$$id"] } }
+            - $project: { _id: 0, x: "$$x", y: "$$y", rand: "$$rand" }
+          # Values in "let" must be constant or closed expressions that do not
+          # depend on document values. This test demonstrates a basic constant
+          # value, a value wrapped with $literal (to avoid expression parsing),
+          # and a closed expression (e.g. $rand).
+          let: &let0
+            id: 1
+            x: foo
+            y: { $literal: "bar" }
+            rand: { $rand: {} }
+        expectResult:
+          - { x: "foo", y: "bar", rand: { $$type: "double" } }
+    expectEvents:
+      - client: *client0
+        events:
+          - commandStartedEvent:
+              command:
+                aggregate: *collection0Name
+                pipeline: *pipeline0
+                let: *let0
+
+  - description: "Aggregate with let option and dollar-prefixed $literal value"
+    runOnRequirements:
+      - minServerVersion: "5.0"
+        # TODO: Remove topology restrictions once SERVER-57403 is resolved
+        topologies: ["single", "replicaset"]
     operations:
       - name: aggregate
         object: *collection0