Make direct writes against the config primary from a JS test throw in the continuous stepdown suite

diff --git a/jstests/libs/override_methods/sharding_continuous_config_stepdown.js b/jstests/libs/override_methods/sharding_continuous_config_stepdown.js

index 638dc8b..7d3039e 100644

--- a/jstests/libs/override_methods/sharding_continuous_config_stepdown.js

+++ b/jstests/libs/override_methods/sharding_continuous_config_stepdown.js

@@ -251,6 +251,29 @@ tracking: {verbosity: 0} }";

         // Start the continuous config server stepdown thread

         this.configRS.startContinuousFailover();

+

+        // We override the functions on Mongo.prototype that send data over the wire to prevent a

+        // test from running a command directly against the config servers and causing a spurious

+        // network error if it coincided with a stepdown.

+        this.configRS.nodes.forEach(function overrideConnectionMethods(node) {

+            var methodsToOverride = [

+                "find",

+                "insert",

+                "remove",

+                "runCommand",

+                "runCommandWithMetadata",

+                "update",

+            ];

+

+            methodsToOverride.forEach(function overrideMethod(name) {

+                node[name] = function throwError() {

+                    throw new Error(

+                        "Cowardly refusing to talk directly to the config servers while running" +

+                        " with the sharding_continuous_config_stepdown.js override enabled since" +

+                        " it may lead to a spurious network error.");

+                };

+            });

+        });

     };

     Object.extend(ShardingTest, originalShardingTest);