From 928b857a6e853339f68d2ad16d0f8376bb275357 Mon Sep 17 00:00:00 2001
From: Yana Kurysheva <kuryshevaya@gmail.com>
Date: Tue, 7 Nov 2023 16:58:27 +0300
Subject: [PATCH] Host check + tests

---
 config.go      |  7 ++++++-
 config_test.go | 17 +++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/config.go b/config.go
index ccd527c..7d197fa 100644
--- a/config.go
+++ b/config.go
@@ -118,6 +118,11 @@ func ParseDSN(dsn string) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	if u.Host == "" {
+		return nil, fmt.Errorf("invalid host")
+	}
+
 	cfg := NewConfig()
 
 	cfg.Scheme, cfg.Host = u.Scheme, u.Host
@@ -184,7 +189,7 @@ func parseDSNParams(cfg *Config, params map[string][]string) (err error) {
 func ensureHavePort(addr string) string {
 	if _, _, err := net.SplitHostPort(addr); err != nil {
 		// we get the missing port error here
-		if addr[0] == '[' && addr[len(addr)-1] == ']' {
+		if len(addr) > 1 && addr[0] == '[' && addr[len(addr)-1] == ']' {
 			// ipv6 brackets
 			addr = addr[1 : len(addr)-1]
 		}
diff --git a/config_test.go b/config_test.go
index cc0667b..0d14cca 100644
--- a/config_test.go
+++ b/config_test.go
@@ -1,6 +1,7 @@
 package clickhouse
 
 import (
+	"fmt"
 	"testing"
 	"time"
 
@@ -53,14 +54,18 @@ func TestDefaultConfig(t *testing.T) {
 }
 
 func TestParseWrongDSN(t *testing.T) {
-	testCases := []string{
-		"http://localhost:8123/?database=test",
-		"http://localhost:8123/?default_format=Native",
-		"http://localhost:8123/?query=SELECT%201",
+	testCases := []struct {
+		dsn         string
+		errExpected error
+	}{
+		{dsn: "http:bad://localhost:8123/?database=test", errExpected: fmt.Errorf("invalid host")},
+		{dsn: "http://localhost:8123/?database=test", errExpected: fmt.Errorf("unknown option 'database'")},
+		{dsn: "http://localhost:8123/?default_format=Native", errExpected: fmt.Errorf("unknown option 'default_format'")},
+		{dsn: "http://localhost:8123/?query=SELECT%201", errExpected: fmt.Errorf("unknown option 'query'")},
 	}
 	for _, tc := range testCases {
-		_, err := ParseDSN(tc)
-		assert.Error(t, err)
+		_, err := ParseDSN(tc.dsn)
+		assert.Equal(t, tc.errExpected, err)
 	}
 }