Fix tests that failed in Jenkins because explain output was different in older server versions.

Author: rstam

tests/MongoDB.Driver.Legacy.Tests/Linq/ExplainTests.cs

@@ -19,6 +19,7 @@
 using MongoDB.Bson;
 using MongoDB.Driver;
 using MongoDB.Driver.Builders;
+using MongoDB.Driver.Core.Misc;
 using MongoDB.Driver.Linq;
 using Xunit;
 
@@ -46,10 +47,14 @@ public void TestExplainFromLinqQueryEqualsExplainFromCursor()
             var linqExplain = _collection.AsQueryable<C>().Where(c => c.X == 2 && c.Y == 1).Take(1).Explain();
             var queryExplain = _collection.FindAs<C>(Query.And(Query.EQ("X", 2), Query.EQ("Y", 1))).SetLimit(1).Explain();
 
-            var linqQuery = linqExplain["queryPlanner"]["parsedQuery"];
-            var findQuery = queryExplain["queryPlanner"]["parsedQuery"];
+            // prior to 3.0.0 this is just a smoke test because the explain output did not have much that could be compared
+            if (CoreTestConfiguration.ServerVersion >= new SemanticVersion(3, 0, 0))
+            {
+                var linqQuery = linqExplain["queryPlanner"]["parsedQuery"];
+                var findQuery = queryExplain["queryPlanner"]["parsedQuery"];
 
-            Assert.Equal(linqQuery, findQuery);
+                Assert.Equal(linqQuery, findQuery);
+            }
         }
 
         [Fact]
@@ -58,10 +63,14 @@ public void TestVerboseExplainFromLinqQueryEqualsVerboseExplainFromCursor()
             var linqExplain = _collection.AsQueryable<C>().Where(c => c.X == 2 && c.Y == 1).Take(1).Explain(true);
             var queryExplain = _collection.FindAs<C>(Query.And(Query.EQ("X", 2), Query.EQ("Y", 1))).SetLimit(1).Explain(true);
 
-            var linqQuery = linqExplain["queryPlanner"]["parsedQuery"];
-            var findQuery = queryExplain["queryPlanner"]["parsedQuery"];
+            // prior to 3.0.0 this is just a smoke test because the explain output did not have much that could be compared
+            if (CoreTestConfiguration.ServerVersion >= new SemanticVersion(3, 0, 0))
+            {
+                var linqQuery = linqExplain["queryPlanner"]["parsedQuery"];
+                var findQuery = queryExplain["queryPlanner"]["parsedQuery"];
 
-            Assert.Equal(linqQuery, findQuery);
+                Assert.Equal(linqQuery, findQuery);
+            }
         }
 
         [Fact]