SERVER-10177 Remove all Js instances of "throw 'string';" with "throw Error();"

Includes both the initial patch to remove all throws and patches for all failing tests

Signed-off-by: Benety Goh <benety@mongodb.com>

9 files changed, 76 insertions, 76 deletions

diff --git a/src/mongo/shell/collection.js b/src/mongo/shell/collection.js
index c9472fb8078..a895fb6f704 100644
--- a/src/mongo/shell/collection.js
+++ b/src/mongo/shell/collection.js
@@ -127,7 +127,7 @@ DBCollection.prototype._massageObject = function( q ){
         return { $where : q };
     }
 
-    throw "don't know how to massage : " + type;
+    throw Error( "don't know how to massage : " + type );
 
 }
 
@@ -137,10 +137,10 @@ DBCollection.prototype._validateObject = function( o ){
     if (this.getMongo()._skipValidation) return;
 
     if (typeof(o) != "object")
-        throw "attempted to save a " + typeof(o) + " value.  document expected.";
+        throw Error( "attempted to save a " + typeof(o) + " value.  document expected." );
 
     if ( o._ensureSpecial && o._checkModify )
-        throw "can't save a DBQuery object";
+        throw Error( "can't save a DBQuery object" );
 }
 
 DBCollection._allowedFields = { $id : 1 , $ref : 1 , $db : 1 };
@@ -152,11 +152,11 @@ DBCollection.prototype._validateForStorage = function( o ){
     this._validateObject( o );
     for ( var k in o ){
         if ( k.indexOf( "." ) >= 0 ) {
-            throw "can't have . in field names [" + k + "]" ;
+            throw Error( "can't have . in field names [" + k + "]" );
         }
 
         if ( k.indexOf( "$" ) == 0 && ! DBCollection._allowedFields[k] ) {
-            throw "field names cannot start with $ [" + k + "]";
+            throw Error( "field names cannot start with $ [" + k + "]" );
         }
 
         if ( o[k] !== null && typeof( o[k] ) === "object" ) {
@@ -185,15 +185,15 @@ DBCollection.prototype.findOne = function( query , fields, options ){
     if ( ! cursor.hasNext() )
         return null;
     var ret = cursor.next();
-    if ( cursor.hasNext() ) throw "findOne has more than 1 result!";
+    if ( cursor.hasNext() ) throw Error( "findOne has more than 1 result!" );
     if ( ret.$err )
-        throw "error " + tojson( ret );
+        throw Error( "error " + tojson( ret ) );
     return ret;
 }
 
 DBCollection.prototype.insert = function( obj , options, _allow_dot ){
     if ( ! obj )
-        throw "no object passed to insert!";
+        throw Error( "no object passed to insert!" );
 
     var flags = 0;
     
@@ -255,7 +255,7 @@ DBCollection.prototype.insert = function( obj , options, _allow_dot ){
             }
             else {
                 // Other exceptions thrown
-                throw ex;
+                throw Error(ex);
             }
         }
     }
@@ -296,7 +296,7 @@ DBCollection.prototype._validateRemoveDoc = function(doc) {
 };
 
 DBCollection.prototype.remove = function( t , justOne ){
-    if (t == undefined) throw "remove needs a query";
+    if (t == undefined) throw Error("remove needs a query");
     var result = undefined;
     var startTime = (typeof(_verboseShell) === 'undefined' ||
                      !_verboseShell) ? 0 : new Date().getTime();
@@ -332,7 +332,7 @@ DBCollection.prototype.remove = function( t , justOne ){
             }
             else {
                 // Other exceptions thrown
-                throw ex;
+                throw Error(ex);
             }
         }
     }
@@ -413,7 +413,7 @@ DBCollection.prototype.update = function( query , obj , upsert , multi ){
             }
             else {
                 // Other exceptions thrown
-                throw ex;
+                throw Error(ex);
             }
         }
     }
@@ -433,10 +433,10 @@ DBCollection.prototype.update = function( query , obj , upsert , multi ){
 
 DBCollection.prototype.save = function( obj , opts ){
     if ( obj == null )
-        throw "can't save a null";
+        throw Error("can't save a null");
 
     if ( typeof( obj ) == "number" || typeof( obj) == "string" )
-        throw "can't save a number or string"
+        throw Error("can't save a number or string");
 
     if ( typeof( obj._id ) == "undefined" ){
         obj._id = new ObjectId();
@@ -494,7 +494,7 @@ DBCollection.prototype._indexSpec = function( keys, options ) {
         }
     }
     else {
-        throw "can't handle: " + typeof( options );
+        throw Error( "can't handle: " + typeof( options ) );
     }
     /*
         return ret;
@@ -574,7 +574,7 @@ DBCollection.prototype.reIndex = function() {
 
 DBCollection.prototype.dropIndexes = function(){
     if ( arguments.length )
-        throw "dropIndexes doesn't take arguments";
+        throw Error("dropIndexes doesn't take arguments");
 
     var res = this._db.runCommand( { deleteIndexes: this.getName(), index: "*" } );
     assert( res , "no result from dropIndex result" );
@@ -584,18 +584,18 @@ DBCollection.prototype.dropIndexes = function(){
     if ( res.errmsg.match( /not found/ ) )
         return res;
 
-    throw "error dropping indexes : " + tojson( res );
+    throw Error( "error dropping indexes : " + tojson( res ) );
 }
 
 
 DBCollection.prototype.drop = function(){
     if ( arguments.length > 0 )
-        throw "drop takes no argument";
+        throw Error("drop takes no argument");
     var ret = this._db.runCommand( { drop: this.getName() } );
     if ( ! ret.ok ){
         if ( ret.errmsg == "ns not found" )
             return false;
-        throw "drop failed: " + tojson( ret );
+        throw Error( "drop failed: " + tojson( ret ) );
     }
     return true;
 }
@@ -611,7 +611,7 @@ DBCollection.prototype.findAndModify = function(args){
         if (ret.errmsg == "No matching object found"){
             return null;
         }
-        throw "findAndModifyFailed failed: " + tojson( ret );
+        throw Error( "findAndModifyFailed failed: " + tojson( ret ) );
     }
     return ret.value;
 }
@@ -1082,7 +1082,7 @@ DBCollection.prototype.totalSize = function(){
 
 DBCollection.prototype.convertToCapped = function( bytes ){
     if ( ! bytes )
-        throw "have to specify # of bytes";
+        throw Error("have to specify # of bytes");
     return this._dbCommand( { convertToCapped : this._shortName , size : bytes } )
 }
 
@@ -1098,14 +1098,14 @@ DBCollection.prototype.isCapped = function(){
 DBCollection.prototype._distinct = function( keyString , query ){
     return this._dbCommand( { distinct : this._shortName , key : keyString , query : query || {} } );
     if ( ! res.ok )
-        throw "distinct failed: " + tojson( res );
+        throw Error( "distinct failed: " + tojson( res ) );
     return res.values;
 }
 
 DBCollection.prototype.distinct = function( keyString , query ){
     var res = this._distinct( keyString , query );
     if ( ! res.ok )
-        throw "distinct failed: " + tojson( res );
+        throw Error( "distinct failed: " + tojson( res ) );
     return res.values;
 }
 
@@ -1221,7 +1221,7 @@ DBCollection.prototype.mapReduce = function( map , reduce , optionsOrOutString )
     var raw = this._db.runCommand( c );
     if ( ! raw.ok ){
         __mrerror__ = raw;
-        throw "map reduce failed:" + tojson(raw);
+        throw Error( "map reduce failed:" + tojson(raw) );
     }
     return new MapReduceResult( this._db , raw );
 
diff --git a/src/mongo/shell/db.js b/src/mongo/shell/db.js
index 3a714b3a984..e4b2daab0ad 100644
--- a/src/mongo/shell/db.js
+++ b/src/mongo/shell/db.js
@@ -40,7 +40,7 @@ DB.prototype.commandHelp = function( name ){
     c.help = true;
     var res = this.runCommand( c );
     if ( ! res.ok )
-        throw res.errmsg;
+        throw Error(res.errmsg);
     return res.help;
 }
 
@@ -125,7 +125,7 @@ DB.prototype.getProfilingLevel  = function() {
 DB.prototype.getProfilingStatus  = function() {
     var res = this._dbCommand( { profile: -1 } );
     if ( ! res.ok )
-        throw "profile command failed: " + tojson( res );
+        throw Error( "profile command failed: " + tojson( res ) );
     delete res.ok
     return res;
 }
@@ -138,7 +138,7 @@ DB.prototype.getProfilingStatus  = function() {
  */
 DB.prototype.dropDatabase = function() {
     if ( arguments.length )
-        throw "dropDatabase doesn't take arguments";
+        throw Error("dropDatabase doesn't take arguments");
     return this._dbCommand( { dropDatabase: 1 } );
 }
 
@@ -164,8 +164,8 @@ DB.prototype.shutdownServer = function(opts) {
     try {
         var res = this.runCommand(cmd);
         if( res )
-            throw "shutdownServer failed: " + res.errmsg;
-        throw "shutdownServer failed";
+            throw Error( "shutdownServer failed: " + res.errmsg );
+        throw Error( "shutdownServer failed" );
     }
     catch ( e ){
         assert( tojson( e ).indexOf( "error doing query: failed" ) >= 0 , "unexpected error: " + tojson( e ) );
@@ -399,7 +399,7 @@ DB.prototype.eval = function(jsfunction) {
     var res = this._dbCommand( cmd );
     
     if (!res.ok)
-        throw tojson( res );
+        throw Error( tojson( res ) );
     
     return res.retval;
 }
@@ -483,7 +483,7 @@ DB.prototype.groupeval = function(parmsObj) {
 DB.prototype.groupcmd = function( parmsObj ){
     var ret = this.runCommand( { "group" : this._groupFixParms( parmsObj ) } );
     if ( ! ret.ok ){
-        throw "group command failed: " + tojson( ret );
+        throw Error( "group command failed: " + tojson( ret ) );
     }
     return ret.retval;
 }
@@ -517,7 +517,7 @@ DB.prototype.forceError = function(){
 DB.prototype.getLastError = function( w , wtimeout ){
     var res = this.getLastErrorObj( w , wtimeout );
     if ( ! res.ok )
-        throw "getlasterror failed: " + tojson( res );
+        throw Error( "getlasterror failed: " + tojson( res ) );
     return res.err;
 }
 DB.prototype.getLastErrorObj = function( w , wtimeout ){
@@ -530,7 +530,7 @@ DB.prototype.getLastErrorObj = function( w , wtimeout ){
     var res = this.runCommand( cmd );
 
     if ( ! res.ok )
-        throw "getlasterror failed: " + tojson( res );
+        throw Error( "getlasterror failed: " + tojson( res ) );
     return res;
 }
 DB.prototype.getLastErrorCmd = DB.prototype.getLastErrorObj;
@@ -589,7 +589,7 @@ DB.prototype.currentOP = DB.prototype.currentOp;
 
 DB.prototype.killOp = function(op) {
     if( !op ) 
-        throw "no opNum to kill specified";
+        throw Error("no opNum to kill specified");
     return this.$cmd.sys.killop.findOne({'op':op});
 }
 DB.prototype.killOP = DB.prototype.killOp;
@@ -880,7 +880,7 @@ DB.prototype._addUserWithInsert = function(userObj, replicatedTo, timeout) {
             print( "Creating user seems to have succeeded but threw an exception because we no " +
                    "longer have auth." );
         } else {
-            throw "Could not insert into system.users: " + tojson(e);
+            throw Error( "Could not insert into system.users: " + tojson(e) );
         }
     }
     print("Successfully added user: " + getUserObjString(userObj));
@@ -922,15 +922,15 @@ DB.prototype._addUserWithInsert = function(userObj, replicatedTo, timeout) {
     }
 
     if (le.err == "timeout") {
-        throw "timed out while waiting for user authentication to replicate - " +
-              "database will not be fully secured until replication finishes"
+        throw Error( "timed out while waiting for user authentication to replicate - " +
+              "database will not be fully secured until replication finishes" )
     }
 
     if (le.err.startsWith("E11000 duplicate key error")) {
-        throw "User already exists with that username/userSource combination";
+        throw Error("User already exists with that username/userSource combination");
     }
 
-    throw "couldn't add user: " + le.err;
+    throw Error( "couldn't add user: " + le.err );
 }
 
 /**
@@ -1017,7 +1017,7 @@ function _hashPassword(username, password) {
 // TODO(spencer): remove this form from v2.8
 DB.prototype._addUserDeprecatedV22Version = function(username, pass, readOnly, replicatedTo, timeout) {
     if ( pass == null || pass.length == 0 )
-        throw "password can't be empty";
+        throw Error("password can't be empty");
 
     var userObjForCommand = { user: username, pwd: pass };
     if (this.getName() == "admin") {
@@ -1153,7 +1153,7 @@ DB.prototype._removeUserV1 = function(username, writeConcern) {
     var le = db.getLastErrorObj(writeConcern['w'], writeConcern['wtimeout']);
 
     if (le.err) {
-        throw "Couldn't remove user: " + le.err;
+        throw Error( "Couldn't remove user: " + le.err );
     }
 
     if (le.n == 1) {
diff --git a/src/mongo/shell/mongo.js b/src/mongo/shell/mongo.js
index 422598ecad1..df8d825c4d5 100644
--- a/src/mongo/shell/mongo.js
+++ b/src/mongo/shell/mongo.js
@@ -8,17 +8,17 @@ if ( typeof Mongo == "undefined" ){
 }
 
 if ( ! Mongo.prototype ){
-    throw "Mongo.prototype not defined";
+    throw Error("Mongo.prototype not defined");
 }
 
 if ( ! Mongo.prototype.find )
-    Mongo.prototype.find = function( ns , query , fields , limit , skip , batchSize , options ){ throw "find not implemented"; }
+    Mongo.prototype.find = function( ns , query , fields , limit , skip , batchSize , options ){ throw Error("find not implemented"); }
 if ( ! Mongo.prototype.insert )
-    Mongo.prototype.insert = function( ns , obj ){ throw "insert not implemented"; }
+    Mongo.prototype.insert = function( ns , obj ){ throw Error("insert not implemented"); }
 if ( ! Mongo.prototype.remove )
-    Mongo.prototype.remove = function( ns , pattern ){ throw "remove not implemented;" }
+    Mongo.prototype.remove = function( ns , pattern ){ throw Error("remove not implemented"); }
 if ( ! Mongo.prototype.update )
-    Mongo.prototype.update = function( ns , query , obj , upsert ){ throw "update not implemented;" }
+    Mongo.prototype.update = function( ns , query , obj , upsert ){ throw Error("update not implemented"); }
 
 if ( typeof mongoInject == "function" ){
     mongoInject( Mongo.prototype );
@@ -44,7 +44,7 @@ Mongo.prototype.getDB = function( name ){
 Mongo.prototype.getDBs = function(){
     var res = this.getDB( "admin" ).runCommand( { "listDatabases" : 1 } );
     if ( ! res.ok )
-        throw "listDatabases failed:" + tojson( res );
+        throw Error( "listDatabases failed:" + tojson( res ) );
     return res;
 }
 
@@ -67,7 +67,7 @@ Mongo.prototype.getDBNames = function(){
 Mongo.prototype.getCollection = function(ns){
     var idx = ns.indexOf( "." );
     if ( idx < 0 ) 
-        throw "need . in ns";
+        throw Error("need . in ns");
     var db = ns.substring( 0 , idx );
     var c = ns.substring( idx + 1 );
     return this.getDB( db ).getCollection( c );
diff --git a/src/mongo/shell/query.js b/src/mongo/shell/query.js
index 6633c88bfac..8e8613fcd86 100644
--- a/src/mongo/shell/query.js
+++ b/src/mongo/shell/query.js
@@ -74,7 +74,7 @@ DBQuery.prototype._ensureSpecial = function(){
 
 DBQuery.prototype._checkModify = function(){
     if ( this._cursor )
-        throw "query already executed";
+        throw Error("query already executed");
 }
 
 DBQuery.prototype._exec = function(){
@@ -126,11 +126,11 @@ DBQuery.prototype.next = function(){
     if ( o )
         this._cursorSeen++;
     else
-        throw "error hasNext: " + o;
+        throw Error( "error hasNext: " + o );
     
     var ret = this._cursor.next();
     if ( ret.$err )
-        throw "error: " + tojson( ret );
+        throw Error( "error: " + tojson( ret ) );
 
     this._numReturned++;
     return ret;
@@ -141,7 +141,7 @@ DBQuery.prototype.objsLeftInBatch = function(){
 
     var ret = this._cursor.objsLeftInBatch();
     if ( ret.$err )
-        throw "error: " + tojson( ret );
+        throw Error( "error: " + tojson( ret ) );
 
     return ret;
 }
@@ -190,7 +190,7 @@ DBQuery.prototype.count = function( applySkipLimit ) {
     
     var res = this._db.runCommand( cmd );
     if( res && res.n != null ) return res.n;
-    throw "count failed: " + tojson( res );
+    throw Error( "count failed: " + tojson( res ) );
 }
 
 DBQuery.prototype.size = function(){
@@ -416,7 +416,7 @@ DBCommandCursor.prototype.next = function() {
     else {
         var ret = this._cursor.next();
         if ( ret.$err )
-            throw "error: " + tojson( ret );
+            throw Error( "error: " + tojson( ret ) );
         return ret;
     }
 }
diff --git a/src/mongo/shell/servers.js b/src/mongo/shell/servers.js
index 145cdaf0c9a..794d5484c21 100755
--- a/src/mongo/shell/servers.js
+++ b/src/mongo/shell/servers.js
@@ -8,7 +8,7 @@ _parsePath = function() {
             dbpath = arguments[ i + 1 ];
 
     if ( dbpath == "" )
-        throw "No dbpath specified";
+        throw Error("No dbpath specified");
 
     return dbpath;
 }
@@ -20,7 +20,7 @@ _parsePort = function() {
             port = arguments[ i + 1 ];
 
     if ( port == "" )
-        throw "No port specified";
+        throw Error("No port specified");
     return port;
 }
 
diff --git a/src/mongo/shell/shardingtest.js b/src/mongo/shell/shardingtest.js
index d3e98245319..6f74762856e 100644
--- a/src/mongo/shell/shardingtest.js
+++ b/src/mongo/shell/shardingtest.js
@@ -288,7 +288,7 @@ ShardingTest = function( testName , numShards , verboseLevel , numMongos , other
     this._configNames = []
     
     if ( otherParams.sync && ! otherParams.separateConfig && numShards < 3 )
-        throw "if you want sync, you need at least 3 servers";
+        throw Error("if you want sync, you need at least 3 servers");
     
     for ( var i = 0; i < ( otherParams.sync ? 3 : 1 ) ; i++ ) {
         
@@ -336,7 +336,7 @@ ShardingTest = function( testName , numShards , verboseLevel , numMongos , other
 
     if ( numMongos == 0 && !otherParams.noChunkSize ) {
         if ( keyFile ) {
-            throw "Cannot set chunk size without any mongos when using auth";
+            throw Error("Cannot set chunk size without any mongos when using auth");
         } else {
             this._configConnection.getDB( "config" ).settings.insert(
                 { _id : "chunksize" , value : otherParams.chunksize || otherParams.chunkSize || 50 } );
@@ -416,7 +416,7 @@ ShardingTest.prototype.getRSEntry = function( setName ){
     for ( var i=0; i<this._rs.length; i++ )
         if ( this._rs[i].setName == setName )
             return this._rs[i];
-    throw "can't find rs: " + setName;
+    throw Error( "can't find rs: " + setName );
 }
 
 ShardingTest.prototype.getConfigIndex = function( config ){
@@ -440,7 +440,7 @@ ShardingTest.prototype.getServerName = function( dbname ){
     if ( x )
         return x.primary;
     this.config.databases.find().forEach( printjson );
-    throw "couldn't find dbname: " + dbname + " total: " + this.config.databases.count();
+    throw Error( "couldn't find dbname: " + dbname + " total: " + this.config.databases.count() );
 }
 
 
@@ -448,7 +448,7 @@ ShardingTest.prototype.getNonPrimaries = function( dbname ){
     var x = this.config.databases.findOne( { _id : dbname } );
     if ( ! x ){
         this.config.databases.find().forEach( printjson );
-        throw "couldn't find dbname: " + dbname + " total: " + this.config.databases.count();
+        throw Error( "couldn't find dbname: " + dbname + " total: " + this.config.databases.count() );
     }
     
     return this.config.shards.find( { _id : { $ne : x.primary } } ).map( function(z){ return z._id; } )
@@ -481,7 +481,7 @@ ShardingTest.prototype.getServer = function( dbname ){
             return c;
     }
     
-    throw "can't find server for: " + dbname + " name:" + name;
+    throw Error( "can't find server for: " + dbname + " name:" + name );
 
 }
 
@@ -494,7 +494,7 @@ ShardingTest.prototype.normalize = function( x ){
 
 ShardingTest.prototype.getOther = function( one ){
     if ( this._connections.length < 2 )
-        throw "getOther only works with 2 servers";
+        throw Error("getOther only works with 2 servers");
 
     if ( one._mongo )
         one = one._mongo
@@ -508,7 +508,7 @@ ShardingTest.prototype.getOther = function( one ){
 
 ShardingTest.prototype.getAnother = function( one ){
     if(this._connections.length < 2)
-    	throw "getAnother() only works with multiple servers";
+        throw Error("getAnother() only works with multiple servers");
 	
 	if ( one._mongo )
         one = one._mongo
@@ -524,7 +524,7 @@ ShardingTest.prototype.getFirstOther = function( one ){
         if ( this._connections[i] != one )
         return this._connections[i];
     }
-    throw "impossible";
+    throw Error("impossible");
 }
 
 ShardingTest.prototype.stop = function(){
@@ -560,7 +560,7 @@ ShardingTest.prototype.adminCommand = function(cmd){
     if ( res && res.ok == 1 )
         return true;
 
-    throw "command " + tojson( cmd ) + " failed: " + tojson( res );
+    throw Error( "command " + tojson( cmd ) + " failed: " + tojson( res ) );
 }
 
 ShardingTest.prototype._rangeToString = function(r){
diff --git a/src/mongo/shell/types.js b/src/mongo/shell/types.js
index 4a1eaf8bde4..2b351e36bd7 100644
--- a/src/mongo/shell/types.js
+++ b/src/mongo/shell/types.js
@@ -61,7 +61,7 @@ ISODate = function(isoDateStr){
     var res = isoDateRegex.exec(isoDateStr);
 
     if (!res)
-        throw "invalid ISO date";
+        throw Error("invalid ISO date");
 
     var year = parseInt(res[1],10) || 1970; // this should always be present
     var month = (parseInt(res[2],10) || 1) - 1;
@@ -455,7 +455,7 @@ Map.hash = function(val){
         return s;
     }
 
-    throw "can't hash : " + typeof(val);
+    throw Error( "can't hash : " + typeof(val) );
 }
 
 Map.prototype.put = function(key, value){
@@ -570,7 +570,7 @@ tojson = function(x, indent, nolint){
     case "function":
         return x.toString();
     default:
-        throw "tojson can't handle type " + (typeof x);
+        throw Error( "tojson can't handle type " + (typeof x) );
     }
 
 }
diff --git a/src/mongo/shell/utils.js b/src/mongo/shell/utils.js
index 9006582a819..41998b352ab 100644
--- a/src/mongo/shell/utils.js
+++ b/src/mongo/shell/utils.js
@@ -515,7 +515,7 @@ shellHelper = function( command , rest , shouldPrint ){
     var args = rest.trim().replace(/\s*;$/,"").split( "\s+" );
     
     if ( ! shellHelper[command] )
-        throw "no command [" + command + "]";
+        throw Error( "no command [" + command + "]" );
     
     var res = shellHelper[command].apply( null , args );
     if ( shouldPrint ){
@@ -726,7 +726,7 @@ shellHelper.show = function (what) {
         }
     }
 
-    throw "don't know how to show [" + what + "]";
+    throw Error( "don't know how to show [" + what + "]" );
 
 }
 
diff --git a/src/mongo/shell/utils_sh.js b/src/mongo/shell/utils_sh.js
index c567e2dee5a..ae1a8694ed7 100644
--- a/src/mongo/shell/utils_sh.js
+++ b/src/mongo/shell/utils_sh.js
@@ -3,7 +3,7 @@ sh = function() { return "try sh.help();" }
 sh._checkMongos = function() {
     var x = db.runCommand( "ismaster" );
     if ( x.msg != "isdbgrid" )
-        throw "not connected to a mongos"
+        throw Error("not connected to a mongos");
 }
 
 sh._checkFullName = function( fullName ) {
@@ -225,7 +225,7 @@ sh.waitForBalancerOff = function( timeout, interval ){
     }
     catch( e ){
         print( "Balancer still may be active, you must manually verify this is not the case using the config.changelog collection." )
-        throw e
+        throw Error(e);
     }
         
     print( "Waiting again for active hosts after balancer is off..." )
@@ -319,13 +319,13 @@ sh._lastMigration = function( ns ){
 sh._checkLastError = function( mydb ) {
     var err = mydb.getLastError();
     if ( err )
-        throw "error: " + err;
+        throw Error( "error: " + err );
 }
 
 sh.addShardTag = function( shard, tag ) {
     var config = db.getSisterDB( "config" );
     if ( config.shards.findOne( { _id : shard } ) == null ) {
-        throw "can't find a shard with name: " + shard;
+        throw Error( "can't find a shard with name: " + shard );
     }
     config.shards.update( { _id : shard } , { $addToSet : { tags : tag } } );
     sh._checkLastError( config );
@@ -334,7 +334,7 @@ sh.addShardTag = function( shard, tag ) {
 sh.removeShardTag = function( shard, tag ) {
     var config = db.getSisterDB( "config" );
     if ( config.shards.findOne( { _id : shard } ) == null ) {
-        throw "can't find a shard with name: " + shard;
+        throw Error( "can't find a shard with name: " + shard );
     }
     config.shards.update( { _id : shard } , { $pull : { tags : tag } } );
     sh._checkLastError( config );