chore: import upstream snapshot with attribution

internal/util/strings_test.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package util
+
+import "testing"
+
+func TestTruncateStr(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		n    int
+		want string
+	}{
+		{"short string", "hello", 10, "hello"},
+		{"exact length", "hello", 5, "hello"},
+		{"truncate", "hello world", 5, "hello"},
+		{"empty", "", 5, ""},
+		{"zero limit", "hello", 0, ""},
+		{"negative limit", "hello", -1, ""},
+		{"CJK characters", "你好世界测试", 4, "你好世界"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := TruncateStr(tt.s, tt.n); got != tt.want {
+				t.Errorf("TruncateStr(%q, %d) = %q, want %q", tt.s, tt.n, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestTruncateStrWithEllipsis(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		n    int
+		want string
+	}{
+		{"short string", "hello", 10, "hello"},
+		{"exact length", "hello", 5, "hello"},
+		{"truncate with ellipsis", "hello world", 8, "hello..."},
+		{"limit less than 3", "hello", 2, "he"},
+		{"limit equals 3", "hello world", 3, "..."},
+		{"empty", "", 5, ""},
+		{"zero limit", "hello", 0, ""},
+		{"negative limit", "hello", -1, ""},
+		{"CJK with ellipsis", "你好世界测试", 5, "你好..."},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := TruncateStrWithEllipsis(tt.s, tt.n); got != tt.want {
+				t.Errorf("TruncateStrWithEllipsis(%q, %d) = %q, want %q", tt.s, tt.n, got, tt.want)
+			}
+		})
+	}
+}