export declare type ExistsOptions = "fail" | "skip" | "overwrite" | "ask";
/**
 * Task:
 *
 * Copy file from src to dest creating the dest dir if required.
 *
 * If `dest` exists, we throw an error by default. We do this because we want
 * our scripts to be clean. We should take explicit steps to remove any file
 * existing at the destination in another part of the script. If we don't, it's
 * easy to end up in a situation where the `copyFile` never executed but we
 * don't know that because overwriting it happens without doing so explicitly.
 *
 * In some situations, when we are copying a fail, we want to treat an existing
 * file in a specific way that may be different from failing. Here are all the
 * options for handling a file that exists at the destination:
 *
 * - `fail`: The copy fails
 * - `skip`: The copy doesn't happen, but the task doesn't fail. Instead, it
 *   informs to the console that the file was skipped.
 * - `overwrite`: The dest file is removed and the copy is allowed to continue
 * - `ask`: If the dest file exists, then we show a diff of the previous and
 *   new file and ask the user if they want to overwrite or not.
 *
 * Can be called with a `silent` option which will supress logging of only the
 * `task` and `pass`. We may later want to suppress others like `overwrite` but
 * we'll leave it for now.
 */
export declare function copyFile(src: string, dest: string, { exists, silent, }?: {
    exists?: ExistsOptions;
    silent?: boolean;
}): void;