export declare const isDevEnv: boolean;
export declare const isTestEnv: boolean;
export declare const isProdEnv: boolean;
/**
 * Digests a string value into a SHA256 hash.
 * @param content - String input
 * @returns Hashed value
 */
export declare function sha256(content: string): string;
/**
 * Parses a boolean string using conventions from CLI arguments, URL query params, and environmental
 * variables. If the input is defined but empty string then true is returned. If the input is
 * undefined or null than false is returned. For example, if the input comes from a CLI arg like
 * `--enable_thing` or URL query param like `?enable_thing`, then this function expects to receive a
 * defined but empty string, and returns true. Otherwise, it checks or values like `true`, `1`,
 * `on`, `yes` (and the inverses). Throws if an unexpected input value is provided.
 */
export declare function parseBoolean(val: string | undefined | null): boolean;
/**
 * Encodes a buffer as a `0x` prefixed lower-case hex string. Returns an empty string if the buffer
 * is zero length.
 */
export declare function bufferToHex(buff: Buffer, prefix?: boolean): string;
/**
 * Decodes a `0x` prefixed hex string to a buffer.
 * @param hex - A hex string with a `0x` prefix.
 */
export declare function hexToBuffer(hex: string): Buffer;
/**
 * Decodes a hex string to a Buffer, trims the 0x-prefix if exists.
 * If already a buffer, returns the input immediately.
 */
export declare function coerceToBuffer(hex: string | Buffer | ArrayBufferView): Buffer;
/**
 * Converts a hex string into a UTF-8 string.
 * @param hex - Hex string
 * @returns UTF-8 string
 */
export declare function hexToUtf8String(hex: string): string;
/**
 * Converts a number to a hex string.
 * @param number - Number
 * @param paddingBytes - Padding bytes
 * @returns Hex string
 */
export declare function numberToHex(number: number, paddingBytes?: number): string;
/**
 * Checks if a string has `0x` prefix.
 * @param val - Hex string
 * @returns Boolean
 */
export declare const has0xPrefix: (val: string) => boolean;
/**
 * Converts a string to an enum value.
 * @param enumType - The enum type
 * @param value - The string value to convert
 * @returns Enum item or undefined
 */
export declare function toEnumValue<T>(enm: {
    [s: string]: T;
}, value: string): T | undefined;
/**
 * Unwraps a value that may be undefined or null.
 * @param val - The value to unwrap
 * @param onNullish - Callback to throw an error if the value is null or undefined
 * @returns The unwrapped value
 */
export declare function unwrap<T>(val: T | null, onNullish?: () => string): Exclude<T, undefined | null>;