Stops unplugging packages when the install scripts are disabled

[arcanis]

Summary

We currently unplug packages by default when they have postinstall scripts, since we can't run them from within the cache. This approach is fine, but we're a bit overzealous and we also do this when the user explicitly disabled the scripts.

This diff ensures that we don't automatically unplug packages anymore when the install scripts are disabled. Of note: packages that have already been unplugged won't be affected by this change (so for example, if you do yarn install && yarn install --ignore-scripts, the packages will still be unplugged).

Test plan

Should be simple enough not to be worth a test?

[edmorley]

Hi!

Trying with Yarn 1.13.0 (which includes this change) this works when using --ignore-scripts however does not when using ignore-scripts true in a .yarnrc in the repository root (even though the console output in both cases mentions ignoring scripts).

Is this expected?

[arcanis]

Nope, not expected 😮 Can you try adding --ignore-scripts true in your .yarnrc and see if it has an effect? I don't see why the two would be any different, but ...

[edmorley]

Using --ignore-scripts true in the .yarnrc worked.

In all cases (CLI flag and both forms of the .yarnrc option) the console output included:
warning Ignored scripts due to flag.

...but I'm presuming that's because the option is retrieved via flags instead?

yarn/src/cli/commands/install.js

Lines 688 to 689 in fcf6298

	if (this.flags.ignoreScripts) {
	this.reporter.warn(this.reporter.lang('ignoredScripts'));

[arcanis]

Well, ignore-scripts true should not have any effect whatsoever - the settings can only be set from the command line afaik (and the yarnrc, but only through the command-line syntax). Compare here:

yarn/src/config.js

Lines 399 to 400 in eb2b565

	this.ignorePlatform = !!opts.ignorePlatform;
	this.ignoreScripts = !!opts.ignoreScripts;

Versus here (which also accepts the no-cli rc defintition):

yarn/src/config.js

Lines 310 to 312 in eb2b565

	cafile: String(opts.cafile || this.getOption('cafile', true) || ''),
	cert: String(opts.cert || this.getOption('cert') || ''),
	key: String(opts.key || this.getOption('key') || ''),

[edmorley]

Well, ignore-scripts true should not have any effect whatsoever

It does affect whether the scripts are run, see:

In all cases (CLI flag and both forms of the .yarnrc option) the console output included:
warning Ignored scripts due to flag.

[edmorley]

I've broken out the issue above to #6893.