npm script to rename files with the version specified in package.json

Question

In the script section of my package.json file, I'm trying to rename some files in a directory, however I would like to inject a value in the command line that is taken from the package.json itself (version).

So in the case below, the build:rename script, I would like it to replace a token in the script (somevalue) before executing it.

In this case I would like to pass in the npm_package_version so that it's part of the name of the file. I'm at a loss...

"scripts": {
    "build:copy": "mkdirp dist && cp src/*.js dist/",
    "build:rename": "renamer --regex --find '(.+)(.js)' --replace '$1**somevalue**$2' dist/*"
}

Answer 1

The current version specified in package.json can be referenced via the script using package.json vars as follows:

---

bash

In bash shells using the syntax - (note the dollar $ prefix):

$npm_package_version

---

Windows

In cmd.exe and Powershell using the syntax - (note the percentage % prefix and suffix):

%npm_package_version%

---

cross-patform

To achieve this cross-platform utlize cross-var:

$ npm i -D cross-var

The build:rename script can be revised as follows:

"scripts": {
  ...
  "build:rename": "cross-var \"renamer --regex --find '\\.js$' --replace '$npm_package_version.js' dist/*\""
},

Note: the additional change to the --find regular expression as cross-var doesn't seem to play nice when the --replace value includes dollar references ($1, $2) to the parenthesised substrings/groups in the --find value. The new regex simply matches the files/strings part ending in .js instead.

---

Example directory

Running the updated build:rename script, (when the version in package.json is 0.3.0), will rename the .js files in the dist directory from this:

.
├── dist
│   ├── a.html
│   ├── b.css
│   ├── foo.js
│   ├── bar.js
│   └── quux.js

...to this:

.
├── dist
│   ├── a.html
│   ├── b.css
│   ├── foo0.3.0.js
│   ├── bar0.3.0.js
│   └── quux0.3.0.js

Additional note

The cp command used in the build:copy script will also not work cross-platform. This can be substituted with the copyfiles package:

$ npm i -D copyfiles

... and the build:copy script then replaced with the following:

"scripts": {
  "build:copy": "copyfiles -u 1 \"src/*.js\" \"dist\"",
   ...
},

The mkdirp dist && part in your script then becomes redundant as copyfiles with create the necessary directory (i.e. dist).

If cross-platform is not necessary for your use-case then simply leave the build:copy script as-is, and change your build:rename script to:

"build:rename": "renamer --regex --find '\\.js$' --replace $npm_package_version'.js' dist/*"