FRS-replace

The fastest (see benchmarks) CLI & Node wrapper around javascript replace which allows on-the-fly replacing (with or without changing input files), globbing, piping and many more!

• Installation
• Node API usage
• CLI usage
• Examples
• Benchmarks

Installation

yarn

yarn add frs-replace

npm

npm install frs-replace

download zipped from FRS-replace Releases

Node API usage

FRS-replace package provides 2 methods for synchronous / asynchronous (with promise and ES6 async/await syntax support) usage:

const FRSReplace = require('FRS-replace');

FRSReplace.sync({/* options */})
FRSReplace.async({/* options */})

Where /* options */ is an object containing:

Note: remember that you need to provide some input for FRS-replace to work, so one of the parameters: input or content are required

Option	Type	Default	Description
input	string or <string>array	undefined	Path/fast-glob pattern to files to read & replace from, if multiple files are specified results are joined with inputJoinString option's value
inputReadOptions	string or object	utf8	Options passed to readFileSync when reading input file
inputGlobOptions	object	undefined	Options passed to fast-glob when resolving glob patterns
inputJoinString	string	\n	String used when joining multiple files, passed directly to javascript join
content	string	undefined	Content to be replaced (takes precedence over file input)
regex	string or RegExp Object	-	Used as a first argument of javascript replace
replacement	string	-	Passed as a second argument to javascript replace
output	string	undefined	Path of an output file
outputWriteOptions	string or object	utf8	Passed as options argument of write's .sync

CLI usage

FRS-replace <regex> <replacement> [options]

Positionals

Option	Type	Description
<regex>	string	First parameter to RegExp constructor
<replacement>	string	String or path to replacement function file (see ‑‑replace‑fn switch for details)

Options

Note: Every boolean option can be negated with use of --no- prefix, e.g. --stdout or --no-stdout turn stdout output on or off, respectively.

Note: Object types can be set using dot notation. So, e.g. if you want to pass utf8 value under i-read-opts encoding field you should write --i-read-opts.encoding utf8.

Option	Type	Default	Description
‑i, ‑‑input	string or <string>array	-	Files/fast-glob pattern to files to read & replace from
‑‑i-read-opts	string or object	utf8	Passed to readFileSync when reading input file
‑‑i-glob-opts	object	undefined	Passed to fast-glob when resolving glob patterns
‑‑i-join-str	string	\n	Used when joining multiple files, passed directly to javascript join
‑o, ‑‑output	string	-	Output file name/path (replaces the file if it already exists and creates any intermediate directories if they don't already exist)
‑‑o-write-opts	string or object	utf8	Passed as options argument of write's .sync
‑f, ‑‑flags	combination of gim flags	g	RegExp flags
‑c, ‑‑content	string	-	Content to be replaced (takes precedence over stream & file input)
‑‑stdout	boolean	true if piped input present, false otherwise	Force sending output on stdout
‑r, ‑‑replace‑fn	boolean	false	Treat replacement argument as path to file containing replacement function
‑h, ‑‑help	boolean	-	Show help
‑v, ‑‑version	boolean	-	Show version number

Examples

Note: while most of examples is using synchronous API method, in all cases .async is applicable as well.

1. Replace all a occurences with b from given foo.js and returns result / writes result to console

1.1 API

const FRSReplace = require('FRS-replace')

/* synchronously */
const resultSync = FRSReplace.sync({
  input       : 'foo.js',
  regex       : new RegExp('a', 'g'),
  replacement : 'b',
  output      : 'foo_replaced.js'
})
// work with result here
  
/* asynchronously */
FRSReplace.async({
  input       : 'foo.js',
  regex       : new RegExp('a', 'g'),
  replacement : 'b'
})
.then(resultAsync => {
  // work with result here */
})

/* asynchronously ES6 syntax (must be runned inside async function) */
const resultAsync = await FRSReplace.async({
  input       : 'foo.js',
  regex       : new RegExp('a', 'g'),
  replacement : 'b'
})
// work with result here */

1.2 CLI

FRS-replace a b -i foo.js --stdout

2. Replace all a occurences with b from given foo.js and save result to foo_replaced.js

2.1 API

const result = require('FRS-replace').sync({
  input       : 'foo.js',
  regex       : new RegExp('a', 'g'),
  replacement : 'b',
  output      : 'foo_replaced.js'
})

2.2 CLI

FRS-replace a b -i foo.js -o foo_replaced.js

3. Replace all a occurences with b from given array of files and save result to foo_replaced.js using default \n as result-joining string

3.1 API

const result = require('FRS-replace').sync({
  input       : ['foo.js', 'foo2.js'],
  regex       : new RegExp('a', 'g'),
  replacement : 'b',
  output      : 'foo_replaced.js'
})

3.2 CLI

FRS-replace a b -i foo.js foo2.js -o foo_replaced.js --i-join-str "\n/////\n"

or

FRS-replace a b -i foo.js -i foo2.js -o foo_replaced.js --i-join-str "\n/////\n"

Note: Arrays can be passed under single flag-entry as a space-separated list or under same flag repeated multiple times (all values will be concatenated into single array using, details - yargs array notation).

4. Replace all a occurences with b from all .js files in foo directory and save result to foo_replaced.js using \n/////\n as result-joining string

4.1 API

const result = require('FRS-replace').sync({
  input           : 'foo/*.js',
  regex           : new RegExp('a', 'g'),
  replacement     : 'b',
  inputJoinString : '\n/////\n',
  output          : 'foo_replaced.js'
})

4.2 CLI

FRS-replace a b -i foo/*.js -o foo_replaced.js --i-join-str "\n/////\n"

5. Replace all a occurences with b in given content string abcd and save result to foo_replaced.js

5.1 API

const result = require('FRS-replace').sync({
  content     : 'abcd',
  regex       : new RegExp('a', 'g'),
  replacement : 'b',
  output      : 'foo_replaced.js'
})

5.2 CLI

FRS-replace a b --content abcd -o foo_replaced.js

6. Replace all a occurences with b from piped stream and save it to output file

6.1 CLI

<read-file> | FRS-replace a b > <output-file-path>

7. Replaces all a occurences with b from piped stream and pass it through stdout stream to next command

7.1 CLI

<read-file> | FRS-replace a b | <next-command>

8. Both pipe & options styles can be mixed together, here - getting input from i argument and passing output down the stream to next command

8.1 CLI

FRS-replace a b -i foo.js | <next-command>

Benchmarks (Node v10.16.0)

input as glob pattern [40 files x 1000 iterations x 100 repetitions]

Library (best bolded)	Execution time [s]	Difference percentage (comparing to best time)
FRS-replace async	0.01764040	102.9716%
FRS-replace sync	0.00869107	0.0000%
replace-in-file	0.02243486	158.1369%
replace async	N/A	N/A
replace sync	0.05524010	535.5961%
replace-string	N/A	N/A

input & replacement as strings [1000 iterations x 100 repetitions]

Library (best bolded)	Execution time [s]	Difference percentage (comparing to best time)
FRS-replace async	0.00010628	231.1801%
FRS-replace sync	0.00003368	4.9407%
replace-in-file	N/A	N/A
replace async	N/A	N/A
replace sync	N/A	N/A
replace-string	0.00003209	0.0000%