If you use transpilation for your package, you may want to avoid committing the compiled JavaScript to your repository while still publishing your scripts to npmjs. However, npm publish/npm pack will use .gitignore to decide on files to exclude from the package unless you create a .npmignore. Thus, one option you have is to maintain both .gitignore and .npmignore. However, this duplicates code.

With this script, you have a second option. Write .gitignore, mark a few lines as excluded from .npmignore, and you’re done!

The script provided by this package, brinkdevteam-derive-npmignore, will automatically read your .gitignore, filter out any lines between #BEGIN_NPMIGNORE_EXCLUDE and #END_NPMIGNORE_EXCLUDE, and output the result to .npmignore. It will also take any lines between #BEGIN_NPMIGNORE_INCLUDE and #END_NPMIGNORE_INCLUDE and remove exactly one # from the beginning of each line.

Example

This example shows how one might combine this with a pattern of developing in TypeScript and publishing compiled JavaScript files with type definitions.

Note that .npmignore is considered a built file when using this pattern!

.gitignore:

# Common editor swap files
*.swp
*~
*\#*

# Build/restored
*.tgz
package-lock.json
node_modules

#BEGIN_NPMIGNORE_EXCLUDE

# Ignore built files.
*.d.ts
*.map
.npmignore

# However, sometimes we need to author and commit custom typings for untyped
# modules or to augment modules which have not been pushed upstream yet. Put
# these *.d.ts files inside of any directory called “types”:
!**/types/*.d.ts

#END_NPMIGNORE_EXCLUDE

#BEGIN_NPMIGNORE_INCLUDE
## TypeScript consumers generally cannot handle it when packages
## publish the source .ts depending on what loader is used to consume
## the files.
#*.ts
#!*.d.ts
#*.tsx
#END_NPMIGNORE_INCLUDE

Put your compilation and call to this sript in the prepare hook which is automatically called by npm pack/npm publish and also called whenever your module is included via a VCS reference.

package.json:

{
  "devDependencies": {
    "@brinkdevteam/derive-npmignore": "^1.1.0",
    "typescript": "^3.0.1"
  },
  "scripts": {
    "prepare": "tsc -d && brinkdevteam-derive-npmignore"
  }
}

Usage

brinkdevteam-derive-npmignore [-h] [--] [path-to-.gitignore [path-to-.npmignore]]

• -h: Prints the basic usage line and exits.

• --: Disabled interpretation of - for the remainder of the arguments. Useful if you may refer to paths starting with -.

• path-to-.gitignore: (Default: .gitignore) You may supply the path to the .gitignore file to use as a template. For example, in one of my projects, that is ../../.gitignore. Regardless of the path to .gitignore, .npmignore will be output to the current directory by default.

• path-to-.npmignore: (Default: .npmignore) You may supply an alternate output path for the .npmignore. For example, you may wish to run this command from outside of the directory which you want to package.