fix(npm packaging): restore prepare script in package.json so that npm install from github works

[appzuka]

Date: Fri Oct 19 16:08:37 2018 +0100

fix(npm packaging): restore prepare script in package.json so that npm install from github works

In commit 2a4d3b the prepare script was removed from package.json.  After that, it is no longer
possible to specify a github location in the project's package.json file to load a specific version
of the package from Github.  It should be possible to load the package using a command such as npm
install github:webpack-contrib/karma-webpack

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

Breaking Changes

Additional Info

[jsf-clabot]

All committers have signed the CLA.

[matthieu-foucault]

According to https://docs.npmjs.com/misc/scripts, prepare and prepublish are both executed when npm install is executed. How does that PR work, given that there is already a prepublish command?

[appzuka]

It looks as if prepublish has been deprecated, although it is not very clear from the help. If I go to a clean directory, npm init, then type

npm install git+https://github.com/webpack-contrib/karma-webpack.git

Then no code is installed under node_modules/karma-webpack. If instead I type

npm install git+https://github.com/appzuka/karma-webpack.git

The package and its dependencies are installed into node_modules, as expected. I am using npm 6.4.1.

npm/npm#10074 gives a detailed description of the confusion. It is possible that users will see a different behaviour depending on the version of npm they are using.

I guess if you publish the package and users install from npmjs they will not see any issue. This is only an issue if users install directly from github. As described in https://docs.npmjs.com/cli/install the prepare script is run in this case so if there is no prepare script the package is not installed.

Now I wonder if having the build step in both prepare and prepublish will mess with the publishing process. It seems to me that it should just be in prepare, so that both publishing and installing from Github will work.

[matthieu-foucault]

I can confirm that prepare fixes it. The prepublish script should be removed though, as it will trigger build twice when running npm install in the karma-webpack directory.

[appzuka]

Agreed. I have removed the prepublish script and tested that installation works with npm directly from github and also with npm install in the local folder.