src/lib/es2019.string.d.ts

interface String {
    /** Removes the trailing white space and line terminator characters from a string. */
    trimEnd(): string;

    /** Removes the leading white space and line terminator characters from a string. */
    trimStart(): string;

    /** Removes the leading white space and line terminator characters from a string. */
    trimLeft(): string;

    /** Removes the trailing white space and line terminator characters from a string. */
    trimRight(): string;
}