@handy-common-utils/fs-utils

@handy-common-utils/fs-utils

File system operations related utilities without any 3rd party dependency.

How to use

First add it as a dependency:

npm install @handy-common-utils/fs-utils

Then you can use it in the code:

import { FsUtils } from '@handy-common-utils/fs-utils';

const [,, filePath, matchPattern, beforeString, afterString] = process.argv;
await FsUtils.addSurroundingInFile(filePath, new RegExp(matchPattern), beforeString, afterString);

You can either import and use the class as shown above, or you can import individual functions directly like below:

import { addSurroundingInFile } from 'fs-utils';

await addSurroundingInFile(README_MD_FILE, /<example>(.*?)<\/example>/gms, '<example><b>', '</b></example>');

There are also several commands you can use directly from your shell/build scripts:

• replace-in-file filePath matchPattern replacement
• replace-in-files matchPattern replacement file1 file2 file3 ...
• replace-in-file-with-file-content filePath matchPattern contentFilePath
• add-surrounding-in-file filePath matchPattern beforeString afterString

API

Module: fs-utils

Re-exports

Functions

• escapeRegExpReplacement = FsUtils.escapeRegExpReplacement
• changeFileContent = FsUtils.changeFileContent
• replaceInFile = FsUtils.replaceInFile
• replaceInFilesWithEncoding = FsUtils.replaceInFilesWithEncoding
• replaceInFiles = FsUtils.replaceInFiles
• addSurroundingInFile = FsUtils.addSurroundingInFile
• replaceInFileWithFileContent = FsUtils.replaceInFileWithFileContent

Exports

Classes

• FsUtils

Type Aliases

FileEncoding

Ƭ FileEncoding: Parameters<Buffer["toString"]>["0"]

---

ReplacementOrBuilder

Ƭ ReplacementOrBuilder: string | (matchPattern: RegExp, filePath: string) => string | PromiseLike<string>

Classes

Class: FsUtils

fs-utils.FsUtils

Constructors

constructor

• new FsUtils()

Methods

addSurroundingInFile

▸ Static addSurroundingInFile(filePath, matchPattern, addBefore, addAfter, fileEncoding?): Promise<void>

Add surrounding content to the matching sections in the text file.

Parameters

Name	Type	Default value	Description
filePath	string	undefined	path to the file
matchPattern	RegExp	undefined	RegExp for deciding which section of the file would be processed. You must have a capturing group in the pattern. You may want to use these tricks: m flag, g flag, s flag, [\s\S]*, .*?
addBefore	string	undefined	the string to be added before the capturing group, no need to escape anything
addAfter	string	undefined	the string to be added before the capturing group, no need to escape anything
fileEncoding	undefined | BufferEncoding	'utf-8'	encoding of the file

Returns

Promise<void>

Promise of void

---

changeFileContent

▸ Static changeFileContent(filePath, transformContent, fileEncoding?): Promise<void>

Change the text file content. This function loads the full content of the file into memory as string, so that it is not suitable for huge (for example, > 500MB) files. If the new content and original content are the same, the file won't be touched.

Parameters

Name	Type	Default value	Description
filePath	string	undefined	path to the file
transformContent	(originalContent: string, filePath: string) => string | PromiseLike<string>	undefined	function for getting the new file content
fileEncoding	undefined | BufferEncoding	'utf-8'	encoding of the file

Returns

Promise<void>

Promise of void

---

escapeRegExpReplacement

▸ Static escapeRegExpReplacement(input): string

Escape the ' sign in the string for using the string as the second argument to String.replace(...)

Parameters

Name	Type	Description
input	string	the original string

Returns

string

a new string with all ' in the original string being replaced by '$'

---

replaceInFile

▸ Static replaceInFile(filePath, matchPattern, replacementOrBuilder, fileEncoding?): Promise<void>

Replace the matching sections in the text file.

Parameters

Name	Type	Default value	Description
filePath	string	undefined	path to the file
matchPattern	RegExp	undefined	RegExp for deciding which section of the file would be replaced. You may want to use these tricks: m flag, g flag, s flag, [\s\S]*, .*?
replacementOrBuilder	ReplacementOrBuilder	undefined	The replacement string or a function for building the replacement string. Please note that you can use special replacement patterns but also you need to take care of the escaping. For details of special replacement patterns see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
fileEncoding	undefined | BufferEncoding	'utf-8'	encoding of the file

Returns

Promise<void>

Promise of void

---

replaceInFileWithFileContent

▸ Static replaceInFileWithFileContent(filePath, matchPattern, contentFilePath, fileEncoding?): Promise<void>

Replace the matching sections in the text file with content from another file.

Parameters

Name	Type	Default value	Description
filePath	string	undefined	path of the file
matchPattern	RegExp	undefined	RegExp for deciding which section of the file would be replaced. You must have a capturing group in the pattern. You may want to use these tricks: m flag, g flag, s flag, [\s\S]*, .*?
contentFilePath	string	undefined	path of the file for getting the replacement content
fileEncoding	undefined | BufferEncoding	'utf-8'	encoding of the files

Returns

Promise<void>

Promise of void

---

replaceInFiles

▸ Static replaceInFiles(matchPattern, replacementOrBuilder, ...filePaths): Promise<void>

Replace the matching sections in multiple utf-8 text files. The replacing opertions on those files happen in parallel.

Parameters

Name	Type	Description
matchPattern	RegExp	RegExp for deciding which section of the file would be replaced. You may want to use these tricks: m flag, g flag, s flag, [\s\S]*, .*?
replacementOrBuilder	ReplacementOrBuilder	The replacement string or a function for building the replacement string. Please note that you can use special replacement patterns but also you need to take care of the escaping. For details of special replacement patterns see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
...filePaths	string[]	patsh to the files

Returns

Promise<void>

Promise of void

---

replaceInFilesWithEncoding

▸ Static replaceInFilesWithEncoding(matchPattern, replacementOrBuilder, fileEncoding, ...filePaths): Promise<void>

Replace the matching sections in multiple text files. The replacing opertions on those files happen in parallel.

Parameters

Name	Type	Description
matchPattern	RegExp	RegExp for deciding which section of the file would be replaced. You may want to use these tricks: m flag, g flag, s flag, [\s\S]*, .*?
replacementOrBuilder	ReplacementOrBuilder	The replacement string or a function for building the replacement string. Please note that you can use special replacement patterns but also you need to take care of the escaping. For details of special replacement patterns see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
fileEncoding	undefined | BufferEncoding	encoding of the file, in most of the cases 'utf-8' should be used
...filePaths	string[]	patsh to the files

Returns

Promise<void>

Promise of void