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:

`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.