@sqlpm/file-async-ts

@sqlpm/file-async-ts

@sqlpm/file-async-ts is a typescript library applying the facade pattern to asynchronous file access.

README: See How to Use This Library to learn how to enable transpilation for local development or tools like jest or ts-node won't work.

Features

• 100% typescript.
• 100% asynchronous library.
• functions
  • fileContentDetailStr - Returns a file path and file content as a string.
  • fileExists - Check if a file exists.
  • readFile - Read from a file returning a Buffer.
  • readFileString -Read from a file returning a string.
  • dirRead Returns a list of files from a directory.
  • parentPaths - Given a path, returns an array of all parent paths.

Usage

fileContentDetailStr - Get a Files Path and Associated Contents

Reads the contents of a file, converting the contents to a string, and returning the contents of the file associated with the path of the file.

• @param path - The absolute or relative path to the file.
• @param [options]
  • [options.required=true] - When true or undefined, when the file is not found an exception is thrown. When false, no exception is thrown and undefined is returned.
• @throws - An error is thrown if the file is not found and options.required was set to true.
• returns - The contents of the file along with the associated path. Undefined may be returned if the options.required was set to false.

@example Return file meta data and content details.

import { join } from 'node:path';
import { fileContentDetailStr } from '@sqlpm/file-async-ts';

(async () => {
  const dir = join(__dirname, 'test-files', 'info.txt');
  const contentDetail = await fileContentDetailStr(dir);
  expect(contentDetail?.content)
    .toEqual('A file with content.');
  expect(contentDetail?.filePath)
    .toMatch(/[\S]*\/__tests__\/test-files\/info.txt$/);
})();

fileExists - Asynchronously Checking if a File Exists

Asynchronously check if a file exists.

• @param path - The absolute or relative path to the file.
• @returns - True when the file exists and false otherwise.

@example Checks if a file exists.

import { join } from 'node:path';
import { fileExists } from '@sqlpm/file-async-ts';

(async () => {
  const dir = join(__dirname, 'file-exists.unit.spec.ts');
  const exists: boolean = await fileExists(dir);
  expect(exists).toEqual(true);
})();

readFile - Asynchronously Read All Contents of a File

Given an absolute or relative path, asynchronously reads all the contents of the file into a buffer.

@remarks Intended use is only for relatively small files. For large files use streams.

• @param path - The absolute or relative path to the file.

• @param [options]

  • [options.required=true] - When true or undefined, when the file is not found an exception is thrown. When false, no exception is thrown and undefined is returned.

• @throws - Errors if the file is not found when options.required is true.

• @returns - Contents of the file as a buffer if the file existed, undefined when required is false and the file was not found.

@example Reads the contents of a file into a Buffer.

import { join } from 'node:path';
import { readFile } from '@sqlpm/file-async-ts';

(async () => {
  const dir = join(__dirname, 'index.ts');
  const content: Buffer | undefined = await readFile(dir);
  console.info(content);
})();

readFileString - Asynchronously Read All Contents of a File Into A String

Given an absolute or relative path, asynchronously reads all the contents of the file into a string.

@remarks Intended use is only for relatively small files. For large files use streams.

• @param path - The absolute or relative path to the file.

• @param [options]

  • [options.required=true] - When true or undefined, when the file is not found an exception is thrown. When false, no exception is thrown and undefined is returned.

• @throws - Errors if the file is not found when options.required is true.

• @returns - Contents of the file as a string if the file existed, undefined when required is false and the file was not found.

@example Reads the contents of a file into a string.

import { join } from 'node:path';
import { readFileString } from '@sqlpm/file-async-ts';

(async () => {
  const dir = join(__dirname, 'read-file.unit.spec.ts');
  const content: string | undefined = await readFileString(dir);
  expect(content).toBeDefined();
})();

dirRead - Return a List of Files Names From a Directory

Given an absolute or relative path, asynchronously returns all of the file names in a directory.

• @param path - The absolute or relative path to the file.
• @param [options]
  • [options.required=true] - When true or undefined, when the directory is not found an exception is thrown. When false, no exception is thrown and undefined is returned.
• @throws - Errors if the directory is not found when options.required is true.
• @returns - An array of file names. @example Get the file names of all files in a given directory.

import {
  dirRead
} from '@sqlpm/file-ts';
(async () => {
  const files: string[] | undefined = await dirRead(__dirname);
  expect(files?.length).toBeGreaterThan(0);
})();

parentPaths - Getting All Paths of a Child Path

Given an absolute path, parentPaths returns an array containing all possible parent paths, including the root path ordered by the child path to the root path.

@remarks The child path is normalized before all possible parent paths are generated. For example, /cat/../and/mouse becomes /and/mouse.

• @param childPath - The absolute path used to generate all possible parent paths.
• @param [options]
  • [options.depth] - The number of parent paths to return, starting from the child path. When undefined, all paths are returned up to and including the root path.
• @throws - An error is thrown if childPath is not an absolute path.
• @returns - An array containing all possible parent paths including the root path ordered by the child path first.

@example Return all parent paths of a child path.

import {
  parentPaths,
} from '@sqlpm/file-async-ts';

const result: string[] = parentPaths('/cat/mouse');
expect(result).toEqual([
  '/cat/mouse',
  '/cat',
  '/',
]);

@example Return all parent paths of a child path, including the child, to a depth of 2.

import {
  parentPaths,
} from '@sqlpm/file-async-ts';

const paths = parentPaths('/a/b/c/d', { depth: 2 });
expect(paths).toEqual(['/a/b/c/d', '/a/b/c']);

Intent

• No Emitted Javascript - The intent is to import this typescript library into a typescript project: compiling to Javascript occurring within the project.
• No Synchronous Calls Exposed - We facade only asynchronous functions as a forcing function to simplify architectural decisions. The intent is to add consistency to how files are consumed within a business organization.

Development

See the monorepo readme.

License

Licensed under MIT. See LICENSE.md.