Interface StringUtils

interface StringUtils {
    upperCase: (str: string) => string;
    lowerCase: (str: string) => string;
    capitalize: (str: string) => string;
    capitalizeWords: (str: string) => string;
    trim: (str: string) => string;
    ltrim: (str: string) => string;
    rtrim: (str: string) => string;
    trimStart: (str: string) => string;
    trimEnd: (str: string) => string;
    pad: (
        str: string,
        length: number,
        char?: string,
        direction?: "left" | "right" | "both",
    ) => string;
    truncate: (str: string, maxLength: number, suffix?: string) => string;
    padStart: (str: string, length: number, char?: string) => string;
    padEnd: (str: string, length: number, char?: string) => string;
}