csv-stringify/lib/index.d.ts

CSV stringifier implementing the Node.js `stream.Transform` API

/// <reference types="node" />

import * as stream from "stream";

export type Callback = (err: Error | undefined, output: string) => void;
export type RecordDelimiter =
  | string
  | Buffer
  | "unix"
  | "mac"
  | "windows"
  | "ascii"
  | "unicode";

export type CastReturnObject = { value: string } & Pick<
  Options,
  | "delimiter"
  | "escape"
  | "quote"
  | "quoted"
  | "quoted_empty"
  | "quoted_string"
  | "quoted_match"
  | "record_delimiter"
>;

export type Cast<T> = (
  value: T,
  context: CastingContext,
) => string | null | CastReturnObject;

export type PlainObject<T> = Record<string, T>;
export type Input = any[];
export interface ColumnOption {
  key: string;
  header?: string;
}
export interface CastingContext {
  readonly column?: number | string;
  readonly header: boolean;
  readonly index: number;
  readonly records: number;
}

export interface OptionsNormalized extends stream.TransformOptions {
  /**
   * Prepend the byte order mark (BOM) to the output stream.
   */
  bom: boolean;
  /**
   * Key-value object which defines custom cast for certain data types
   */
  cast?: {
    boolean?: Cast<boolean>;
    date?: Cast<Date>;
    number?: Cast<number>;
    bigint?: Cast<bigint>;
    /**
     * Custom formatter for generic object values
     */
    object?: Cast<Record<string, any>>;
    string?: Cast<string>;
  };
  /**
   * List of fields, applied when `transform` returns an object
   * order matters
   * read the transformer documentation for additionnal information
   * columns are auto discovered in the first record when the user write objects
   * can refer to nested properties of the input JSON
   * see the "header" option on how to print columns names on the first line
   */
  columns: ReadonlyArray<string | ColumnOption> | PlainObject<string>;
  /**
   * Set the field delimiter, one character only, defaults to a comma.
   */
  delimiter: string;
  /**
   * Add the value of "options.RecordDelimiter" on the last line, default to true.
   */
  eof: boolean;
  /**
   * Defaults to the escape read option.
   */
  escape: string;
  /**
   * Display the column names on the first line if the columns option is provided or discovered.
   */
  header: boolean;
  /**
   * The quote characters, defaults to the ", an empty quote value will preserve the original field.
   */
  quote: string;
  /**
   * Boolean, default to false, quote all the non-empty fields even if not required.
   */
  quoted: boolean;

  /**
   * Boolean, no default, quote empty fields and overrides `quoted_string` on empty strings when defined.
   */
  quoted_empty: boolean;
  /**
   * String or RegExp, no default, quote all fields matching a regular expression.
   */
  quoted_match: null | (string | RegExp)[];
  /**
   * Boolean, default to false, quote all fields of type string even if not required.
   */
  quoted_string: boolean;
  /**
   * String used to delimit record rows or a special value
   * special values are 'unix', 'mac', 'windows', 'ascii', 'unicode'
   * defaults to '\n'.
   */
  record_delimiter: RecordDelimiter;
  /**
   * Boolean, default to false, if true, fields that begin with `=`, `+`, `-`, `@`, `\t`, or `\r` will be prepended with a `'` to protected agains csv injection attacks
   */
  escape_formulas: boolean;
}

export interface Options extends stream.TransformOptions {
  /**
   * Prepend the byte order mark (BOM) to the output stream.
   */
  bom?: boolean;
  /**
   * Key-value object which defines custom cast for certain data types
   */
  cast?: {
    boolean?: Cast<boolean>;
    date?: Cast<Date>;
    number?: Cast<number>;
    bigint?: Cast<bigint>;
    /**
     * Custom formatter for generic object values
     */
    object?: Cast<Record<string, any>>;
    string?: Cast<string>;
  };
  /**
   * List of fields, applied when `transform` returns an object
   * order matters
   * read the transformer documentation for additionnal information
   * columns are auto discovered in the first record when the user write objects
   * can refer to nested properties of the input JSON
   * see the "header" option on how to print columns names on the first line
   */
  columns?: ReadonlyArray<string | ColumnOption> | PlainObject<string>;
  /**
   * Set the field delimiter, one character only, defaults to a comma.
   */
  delimiter?: string | Buffer;
  /**
   * Add the value of "options.RecordDelimiter" on the last line, default to true.
   */
  eof?: boolean;
  /**
   * Defaults to the escape read option.
   */
  escape?: string | Buffer;
  /**
   * Display the column names on the first line if the columns option is provided or discovered.
   */
  header?: boolean;
  /**
   * The quote characters, defaults to the ", an empty quote value will preserve the original field.
   */
  quote?: string | Buffer | boolean;
  /**
   * Boolean, default to false, quote all the non-empty fields even if not required.
   */
  quoted?: boolean;

  /**
   * Boolean, no default, quote empty fields and overrides `quoted_string` on empty strings when defined.
   */
  quoted_empty?: boolean;
  /**
   * String or RegExp, no default, quote all fields matching a regular expression.
   */
  quoted_match?: null | string | RegExp | (string | RegExp)[];
  /**
   * Boolean, default to false, quote all fields of type string even if not required.
   */
  quoted_string?: boolean;
  /**
   * String used to delimit record rows or a special value
   * special values are 'unix', 'mac', 'windows', 'ascii', 'unicode'
   * defaults to '\n'.
   */
  record_delimiter?: RecordDelimiter;
  /**
   * Boolean, default to false, if true, fields that begin with `=`, `+`, `-`, `@`, `\t`, or `\r` will be prepended with a `'` to protected agains csv injection attacks
   */
  escape_formulas?: boolean;
}

export class Stringifier extends stream.Transform {
  constructor(options: Options);
  readonly options: OptionsNormalized;
}

declare function stringify(callback?: Callback): Stringifier;
declare function stringify(options: Options, callback?: Callback): Stringifier;
declare function stringify(input: Input, callback?: Callback): Stringifier;
declare function stringify(
  input: Input,
  options?: Options,
  callback?: Callback,
): Stringifier;

// export default stringify
export { stringify };