GODRIVER-1999 allow directConnection=false in loadBalanced=true URIs (#683)

Author: iwysiu

data/initial-dns-seedlist-discovery/load-balanced/loadBalanced-directConnection-errors.json

@@ -0,0 +1,14 @@
+{
+  "uri": "mongodb+srv://test20.test.build.10gen.cc/?directConnection=false",
+  "seeds": [
+    "localhost.test.build.10gen.cc:27017"
+  ],
+  "hosts": [
+    "localhost.test.build.10gen.cc:27017"
+  ],
+  "options": {
+    "loadBalanced": true,
+    "ssl": true,
+    "directConnection": false
+  }
+}

data/initial-dns-seedlist-discovery/load-balanced/loadBalanced-directConnection-errors.yml

@@ -0,0 +1,13 @@
+# The TXT record for test20.test.build.10gen.cc contains loadBalanced=true.
+# DRIVERS-1721 introduced this test as passing.
+uri: "mongodb+srv://test20.test.build.10gen.cc/?directConnection=false"
+seeds:
+    - localhost.test.build.10gen.cc:27017
+hosts:
+    # In LB mode, the driver does not do server discovery, so the hostname does
+    # not get resolved to localhost:27017.
+    - localhost.test.build.10gen.cc:27017
+options:
+    loadBalanced: true
+    ssl: true
+    directConnection: false

data/initial-dns-seedlist-discovery/load-balanced/loadBalanced-directConnection.json

@@ -180,6 +180,18 @@
         "loadBalanced": true
       }
     },
+    {
+      "description": "loadBalanced=true with directConnection=false",
+      "uri": "mongodb://example.com/?loadBalanced=true&directConnection=false",
+      "valid": true,
+      "warning": false,
+      "hosts": null,
+      "auth": null,
+      "options": {
+        "loadBalanced": true,
+        "directConnection": false
+      }
+    },
     {
       "description": "loadBalanced=false",
       "uri": "mongodb://example.com/?loadBalanced=false",
@@ -218,15 +230,6 @@
       "auth": null,
       "options": {}
     },
-    {
-      "description": "loadBalanced=true with directConnection=false causes an error",
-      "uri": "mongodb://example.com/?loadBalanced=true&directConnection=false",
-      "valid": false,
-      "warning": false,
-      "hosts": null,
-      "auth": null,
-      "options": {}
-    },
     {
       "description": "loadBalanced=true with replicaSet causes an error",
       "uri": "mongodb://example.com/?loadBalanced=true&replicaSet=replset",

data/initial-dns-seedlist-discovery/load-balanced/loadBalanced-directConnection.yml

@@ -156,6 +156,16 @@ tests:
       auth: ~
       options:
           loadBalanced: true
+    -
+      description: loadBalanced=true with directConnection=false
+      uri: "mongodb://example.com/?loadBalanced=true&directConnection=false"
+      valid: true
+      warning: false
+      hosts: ~
+      auth: ~
+      options:
+          loadBalanced: true
+          directConnection: false
     -
       description: loadBalanced=false
       uri: "mongodb://example.com/?loadBalanced=false"
@@ -189,14 +199,6 @@ tests:
       hosts: ~
       auth: ~
       options: {}
-    -
-      description: loadBalanced=true with directConnection=false causes an error
-      uri: "mongodb://example.com/?loadBalanced=true&directConnection=false"
-      valid: false
-      warning: false
-      hosts: ~
-      auth: ~
-      options: {}
     -
       description: loadBalanced=true with replicaSet causes an error
       uri: "mongodb://example.com/?loadBalanced=true&replicaSet=replset"

data/uri-options/connection-options.json

@@ -340,6 +340,9 @@ func (p *parser) validate() error {
 		if p.Scheme == SchemeMongoDBSRV {
 			return errors.New("a direct connection cannot be made if an SRV URI is used")
 		}
+		if p.LoadBalancedSet && p.LoadBalanced {
+			return internal.ErrLoadBalancedWithDirectConnection
+		}
 	}
 
 	// Validation for load-balanced mode.
@@ -350,9 +353,6 @@ func (p *parser) validate() error {
 		if p.ReplicaSet != "" {
 			return internal.ErrLoadBalancedWithReplicaSet
 		}
-		if p.ConnectSet || p.DirectConnectionSet {
-			return internal.ErrLoadBalancedWithDirectConnection
-		}
 	}
 
 	return nil