Fix USING TIMEOUT time generation (#299)

Scylla does not support fractions.
We need to make sure that time is formatted the following way: XmYsZms

qb/using.go

@@ -94,7 +94,7 @@ func (u *using) writeCql(cql *bytes.Buffer) (names []string) {
 
 	if u.timeout != 0 {
 		writePreamble(cql)
-		fmt.Fprintf(cql, "TIMEOUT %s ", u.timeout)
+		fmt.Fprintf(cql, "TIMEOUT %s ", formatDuration(u.timeout))
 	} else if u.timeoutName != "" {
 		writePreamble(cql)
 		cql.WriteString("TIMEOUT ? ")

qb/using_test.go

@@ -57,6 +57,11 @@ func TestUsing(t *testing.T) {
 			B: new(using).Timeout(time.Second),
 			S: "USING TIMEOUT 1s ",
 		},
+		// Timeout faction
+		{
+			B: new(using).Timeout(time.Second + 100*time.Millisecond),
+			S: "USING TIMEOUT 1s100ms ",
+		},
 		// TimeoutNamed
 		{
 			B: new(using).TimeoutNamed("to"),

qb/utils.go

@@ -6,6 +6,9 @@ package qb
 
 import (
 	"bytes"
+	"fmt"
+	"strings"
+	"time"
 )
 
 // placeholders returns a string with count ? placeholders joined with commas.
@@ -31,3 +34,26 @@ func (cols columns) writeCql(cql *bytes.Buffer) {
 		}
 	}
 }
+
+func formatDuration(d time.Duration) string {
+	// Round the duration to the nearest millisecond
+	// Extract hours, minutes, seconds, and milliseconds
+	minutes := d / time.Minute
+	d %= time.Minute
+	seconds := d / time.Second
+	d %= time.Second
+	milliseconds := d / time.Millisecond
+
+	// Format the duration string
+	var res []string
+	if minutes > 0 {
+		res = append(res, fmt.Sprintf("%dm", minutes))
+	}
+	if seconds > 0 {
+		res = append(res, fmt.Sprintf("%ds", seconds))
+	}
+	if milliseconds > 0 {
+		res = append(res, fmt.Sprintf("%dms", milliseconds))
+	}
+	return strings.Join(res, "")
+}

qb/utils_test.go

@@ -0,0 +1,61 @@
+package qb
+
+import (
+	"testing"
+	"time"
+)
+
+func TestFormatDuration(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    time.Duration
+		expected string
+	}{
+		{
+			name:     "Zero duration",
+			input:    0,
+			expected: "",
+		},
+		{
+			input:    500 * time.Millisecond,
+			expected: "500ms",
+		},
+		{
+			input:    10 * time.Second,
+			expected: "10s",
+		},
+		{
+			input:    3 * time.Minute,
+			expected: "3m",
+		},
+		{
+			input:    (2 * time.Minute) + (30 * time.Second),
+			expected: "2m30s",
+		},
+		{
+			input:    (15 * time.Second) + (250 * time.Millisecond),
+			expected: "15s250ms",
+		},
+		{
+			input:    (1 * time.Minute) + (45 * time.Second) + (123 * time.Millisecond),
+			expected: "1m45s123ms",
+		},
+		{
+			input:    (5 * time.Minute) + (1 * time.Second) + (999 * time.Millisecond),
+			expected: "5m1s999ms",
+		},
+		{
+			input:    (2 * time.Second) + (1500 * time.Millisecond), // 3 seconds, 500ms
+			expected: "3s500ms",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			actual := formatDuration(tt.input)
+			if actual != tt.expected {
+				t.Errorf("got %q, want %q", actual, tt.expected)
+			}
+		})
+	}
+}