@frsource/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
• ⌨️ CLI API
• 🔎 Example usage
  • 1. Replace all a occurences with b from given foo.js file and return result / write result to the console
  • 2. Replace all a occurences with b from given foo.js and save result to the foo_replaced.js
  • 3. Replace all a occurences with b from given array of files and save result to the foo_replaced.js using default \n as result-joining string
  • 4. Replace all a occurences with b from all .js files in foo directory and save result to the foo_replaced.js using \n/////\n as result-joining string
  • 5. Replace all a occurences with b in given content string abcd and save result to the foo_replaced.js
  • 6. Replace all a occurences with b from piped stream and save it to the output file
  • 7. Replace all a occurences with b from piped stream and pass it through stdout stream to the <next-command>
  • 8. Both pipe & options styles can be mixed together, here - getting input from -i argument and passing output down the stream to the <next-command>
• 📈 Benchmarks

📜 Installation

yarn add @frsource/frs-replace

or

npm install @frsource/frs-replace

or download zipped from @frsource/frs-replace releases

📚 Node API

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

const FRSReplace = require('@frsource/frs-replace');
// or
import * as FRSReplace from '@frsource/frs-replace';

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

// you might also want to import methods separately (e.g. import only one of them):
const FRSReplaceSync = require('@frsource/frs-replace/sync');
const FRSReplaceAsync = require('@frsource/frs-replace/async');
// or
import { sync, async } from '@frsource/frs-replace';

Where /* options */ is an object containing:

Note: remember that you need to provide some input for @frsource/frs-replace to work, so one of parameters: input or content is required

Option	Type	Default	Description
input	string or string[]	undefined	Path to files or fast-glob pattern pointing to files to be read & replaced from. If multiple files specified results will be joined using outputJoinString option's value)
inputReadOptions	string or object	utf8	Options which are passed directly to the readFileSync method when reading input file
inputGlobOptions	object	undefined	Options which are passed directly to the fast-glob package when resolving glob patterns
content	string	undefined	Content to be replaced (takes precedence over file input)
strategy	"join" or "flatten" or "preserve-structure"	"join"	Output file generation strategy. "join" - joins all input files and outputs them as a single file using path passed as: "output". "preserve-structure" - saves all files to the "output" directory keeping relative directory structure."flatten" - same as "preserve-structure" but flattens the directory structure
needle	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
outputJoinString	string	\n	String used when joining multiple files, passed directly to javascript join

⌨️ CLI API

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[]	-	Path to files or fast-glob pattern pointing to files to be read & replaced from. If multiple files specified results will be joined using outputJoinString option's value)
‑‑i-read-opts	string or object	utf8	Options which are passed directly to the readFileSync method when reading input file
‑‑i-glob-opts	object	undefined	Options which are passed directly to the fast-glob package when resolving glob patterns
‑‑stdin	boolean	true	Wait for stdin input (should be set to false when used in non-interactive terminals)
‑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
‑‑o-join-str	string	\n	Used when joining multiple files, passed directly to javascript join
‑c, ‑‑content	string	-	Content to be replaced (takes precedence over stream & file input)
‑s, ‑‑strategy	"join" or "flatten" or "preserve-structure"	"join"	Output file generation strategy. "join" - joins all input files and outputs them as a single file using path passed as: "output". "preserve-structure" - saves all files to the "output" directory keeping relative directory structure."flatten" - same as "preserve-structure" but flattens the directory structure
‑f, ‑‑flags	combination of gim flags	g	RegExp flags
‑‑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

🔎 Example usage

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

1. Replace all a occurences with b from given foo.js file and return result / write result to the console

Click to expand

1.1 API

const FRSReplace = require('@frsource/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 the foo_replaced.js

Click to expand

2.1 API

const result = require('@frsource/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 the foo_replaced.js using default \n as result-joining string

Click to expand

3.1 API

const result = require('@frsource/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

or

frs-replace a b -i foo.js -i foo2.js -o foo_replaced.js

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 the foo_replaced.js using \n/////\n as result-joining string

Click to expand

4.1 API

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

4.2 CLI

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

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

Click to expand

5.1 API

const result = require('@frsource/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 the output file

6.1 CLI

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

7. Replace all a occurences with b from piped stream and pass it through stdout stream to the <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 the <next-command>

8.1 CLI

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

📈 Benchmarks

Tested on Node v15.0.1.

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	0.01959564	57.5020%
frs-replace sync	0.01244152	0.0000%
replace-in-file	0.02223758	78.7368%
replace async	N/A	N/A
replace sync	0.06111267	391.1992%
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	0.00020093	516.9883%
frs-replace sync	0.00003257	0.0000%
replace-in-file	N/A	N/A
replace async	N/A	N/A
replace sync	N/A	N/A
replace-string	0.00003438	5.5692%