Allow putting test connection string into .connstr file

.gitignore

@@ -0,0 +1,2 @@
+/.idea
+/.connstr

conn_str_test.go

@@ -1,6 +1,8 @@
 package mssql
 
 import (
+	"bufio"
+	"io"
 	"os"
 	"reflect"
 	"testing"
@@ -182,14 +184,33 @@ func testConnParams(t testing.TB) connectParams {
 		params.logFlags = logFlags
 		return params
 	}
-	return connectParams{
-		host: os.Getenv("HOST"),
-		instance: os.Getenv("INSTANCE"),
-		database: os.Getenv("DATABASE"),
-		user: os.Getenv("SQLUSER"),
-		password: os.Getenv("SQLPASSWORD"),
-		logFlags: logFlags,
+	if len(os.Getenv("HOST")) > 0 && len(os.Getenv("DATABASE")) > 0 {
+		return connectParams{
+			host: os.Getenv("HOST"),
+			instance: os.Getenv("INSTANCE"),
+			database: os.Getenv("DATABASE"),
+			user: os.Getenv("SQLUSER"),
+			password: os.Getenv("SQLPASSWORD"),
+			logFlags: logFlags,
+		}
+	}
+	// try loading connection string from file
+	f, err := os.Open(".connstr")
+	if err == nil {
+		rdr := bufio.NewReader(f)
+		dsn, err := rdr.ReadString('\n')
+		if err != io.EOF {
+			t.Fatal(err)
+		}
+		params, err := parseConnectParams(dsn)
+		if err != nil {
+			t.Fatal("unable to parse connection string loaded from file", err)
+		}
+		params.logFlags = logFlags
+		return params
 	}
+	t.Skip("no database connection string")
+	return connectParams{}
 }
 
 func TestConnParseRoundTripFixed(t *testing.T) {

tds_test.go

@@ -7,7 +7,6 @@ import (
 	"encoding/hex"
 	"net"
 	"net/url"
-	"os"
 	"runtime"
 	"testing"
 )
@@ -165,13 +164,7 @@ func TestSendSqlBatch(t *testing.T) {
 }
 
 func checkConnStr(t testing.TB) {
-	if len(os.Getenv("SQLSERVER_DSN")) > 0 {
-		return
-	}
-	if len(os.Getenv("HOST")) > 0 && len(os.Getenv("DATABASE")) > 0 {
-		return
-	}
-	t.Skip("no database connection string")
+	testConnParams(t)
 }
 
 // makeConnStr returns a URL struct so it may be modified by various