Add missing tests for load-balancer specification

source/load-balancers/tests/dns-seedlist-discovery.yml

@@ -0,0 +1,48 @@
+description: DNS seedlist discovery for load-balanced clusters
+
+schemaVersion: '1.4'
+
+runOnRequirements:
+  - topologies: [ load-balanced ]
+
+createEntities:
+  - client:
+      id: &client0 client0
+      useMultipleMongoses: true
+      observeEvents:
+        - topologyDescriptionChangedEvent
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: &database0Name database0
+
+tests:
+  - description: SRV polling is disabled with loadBalanced=true
+    operations:
+      # Wait for initial topology description events
+      - name: waitForEvent
+        object: testRunner
+        arguments:
+          client: *client0
+          event:
+            topologyDescriptionChangedEvent:
+              topologyType: LoadBalanced
+      # Wait long enough for any SRV polling to occur (if implemented)
+      - name: wait
+        object: testRunner
+        arguments:
+          ms: 60000
+      # Run an operation to check that we're still connected
+      - name: runCommand
+        object: *database0
+        arguments:
+          commandName: ping
+          command: { ping: 1 }
+      # Verify that no additional topology events were published
+      - name: assertEventCount
+        object: testRunner
+        arguments:
+          client: *client0
+          event:
+            topologyDescriptionChangedEvent: 2
+          count: 2  # Only two events: initial Unknown -> LoadBalanced, and LoadBalanced server details

source/load-balancers/tests/driver-sessions.yml

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+description: driver sessions for load-balanced clusters
+
+schemaVersion: '1.4'
+
+runOnRequirements:
+  - topologies: [ load-balanced ]
+
+createEntities:
+  - client:
+      id: &client0 client0
+      useMultipleMongoses: true
+      observeEvents:
+        - commandStartedEvent
+  - database:
+      id: &database0 database0
+      client: *client0
+      databaseName: &database0Name database0
+  - collection:
+      id: &collection0 collection0
+      database: *database0
+      collectionName: &collection0Name collection0
+
+tests:
+  - description: sessions are always supported with load-balanced topology
+    operations:
+      - name: createClientSession
+        object: *client0
+        arguments: {}
+        saveResultAsEntity: &session0 session0
+      # Perform a simple operation with the session
+      - name: insertOne
+        object: *collection0
+        arguments:
+          document: { x: 1 }
+          session: *session0
+
+  - description: ServerType LoadBalancer is considered a data-bearing server
+    operations:
+      # The previous test already verifies this implicitly by allowing insertOne,
+      # but we can add additional operations
+      - name: createClientSession
+        object: *client0
+        arguments: {}
+        saveResultAsEntity: &session1 session1
+      - name: runCommand
+        object: *database0
+        arguments:
+          commandName: ping
+          command: { ping: 1 }
+          session: *session1
+      # Test that we can use read operations as well (which require a data-bearing server)
+      - name: find
+        object: *collection0
+        arguments:
+          filter: {}
+          session: *session1