Add option to set DateFirst

src/connection.js

@@ -31,6 +31,7 @@ const DEFAULT_CLIENT_REQUEST_TIMEOUT = 15 * 1000;
 const DEFAULT_CANCEL_TIMEOUT = 5 * 1000;
 const DEFAULT_PACKET_SIZE = 4 * 1024;
 const DEFAULT_TEXTSIZE = '2147483647';
+const DEFAULT_DATEFIRST = 7;
 const DEFAULT_PORT = 1433;
 const DEFAULT_TDS_VERSION = '7_4';
 
@@ -61,6 +62,7 @@ class Connection extends EventEmitter {
         connectionIsolationLevel: ISOLATION_LEVEL.READ_COMMITTED,
         cryptoCredentialsDetails: {},
         database: undefined,
+        datefirst: DEFAULT_DATEFIRST,
         enableArithAbort: false,
         enableAnsiNullDefault: true,
         encrypt: false,
@@ -127,6 +129,14 @@ class Connection extends EventEmitter {
         this.config.options.database = config.options.database;
       }
 
+      if (config.options.datefirst) {
+        if (config.options.datefirst < 1 || config.options.port > 7) {
+          throw new RangeError('DateFirst should be >= 1 and <= 7');
+        }
+
+        this.config.options.datefirst = config.options.datefirst;
+      }
+
       if (config.options.enableAnsiNullDefault != undefined) {
         this.config.options.enableAnsiNullDefault = config.options.enableAnsiNullDefault;
       }
@@ -711,7 +721,7 @@ class Connection extends EventEmitter {
     const xact_abort = this.config.options.abortTransactionOnError ? 'on' : 'off';
     const enableAnsiNullDefault = this.config.options.enableAnsiNullDefault ? 'on' : 'off';
     const enableArithAbort = this.config.options.enableArithAbort ? 'on' : 'off';
-    return 'set textsize ' + this.config.options.textsize + '\nset quoted_identifier on\nset arithabort ' + enableArithAbort + '\nset numeric_roundabort off\nset ansi_warnings on\nset ansi_padding on\nset ansi_nulls on\nset ansi_null_dflt_on ' + enableAnsiNullDefault + '\nset concat_null_yields_null on\nset cursor_close_on_commit off\nset implicit_transactions off\nset language us_english\nset dateformat mdy\nset datefirst 7\nset transaction isolation level ' + (this.getIsolationLevelText(this.config.options.connectionIsolationLevel)) + '\nset xact_abort ' + xact_abort;
+    return 'set textsize ' + this.config.options.textsize + '\nset quoted_identifier on\nset arithabort ' + enableArithAbort + '\nset numeric_roundabort off\nset ansi_warnings on\nset ansi_padding on\nset ansi_nulls on\nset ansi_null_dflt_on ' + enableAnsiNullDefault + '\nset concat_null_yields_null on\nset cursor_close_on_commit off\nset implicit_transactions off\nset language us_english\nset dateformat mdy\nset datefirst ' + this.config.options.datefirst + '\nset transaction isolation level ' + (this.getIsolationLevelText(this.config.options.connectionIsolationLevel)) + '\nset xact_abort ' + xact_abort;
   }
 
   processedInitialSql() {

test/integration/connection-test.coffee

@@ -240,7 +240,7 @@ runNtlmTest = (test, domainCase) ->
   )
 
 exports.ntlm = (test) ->
-  runNtlmTest test, DomainCaseEnum.AsIs 
+  runNtlmTest test, DomainCaseEnum.AsIs
 
 exports.ntlmLower = (test) ->
   runNtlmTest test, DomainCaseEnum.Lower
@@ -1056,7 +1056,6 @@ exports.disableAnsiNullDefault = (test) ->
 
 testArithAbort = (test, setting) ->
   test.expect(5)
-
   config = getConfig()
   config.options.enableArithAbort = setting if typeof setting is 'boolean'
 
@@ -1106,3 +1105,49 @@ exports.badArithAbort = (test) ->
     connection = new Connection(config)
 
   test.done()
+
+testDateFirstImpl = (test, datefirst) =>
+  datefirst = datefirst || 7
+  test.expect(3)
+  config = getConfig()
+  config.options.datefirst = datefirst
+
+  connection = new Connection(config)
+
+  request = new Request('select @@datefirst', (err) ->
+    test.ifError(err)
+    connection.close()
+  )
+
+  request.on('row', (columns) ->
+    dateFirstActual = columns[0].value
+    test.strictEqual(dateFirstActual, datefirst)
+  )
+
+  connection.on 'connect', (err) ->
+    test.ifError(err)
+    connection.execSql(request)
+
+  connection.on 'end', (info) ->
+    test.done()
+
+# Test that the default setting for DATEFIRST is 7
+exports.testDatefirstDefault = (test) ->
+  testDateFirstImpl(test, undefined)
+
+# Test that the DATEFIRST setting can be changed via an optional configuration
+exports.testDatefirstCustom = (test) ->
+  testDateFirstImpl(test, 3)
+
+# Test that an invalid DATEFIRST setting throws
+exports.badDatefirst = (test) ->
+  test.expect(1)
+  config = getConfig()
+  config.options.datefirst = -1
+
+  connection = null
+
+  test.throws ->
+    connection = new Connection(config)
+
+  test.done()