Install dependencies of build script.

[nojaf]

Description

I'd like a way to download dependencies of the build script without invoking anything else.

Scenario:

I want to add a new module nuget Fake.JavaScript.Npm.
Before I can add open Fake.JavaScript I need to have that dependency installed.

Repro steps

Please provide the steps required to reproduce the problem

1. Delete build.fsx.lock file

2. Run fake.exe run build.fsx --help

With --help no target is invoked it does contain side effects however.

Expected behavior

I'd be nice if there were a fake.exe install to fetch the new dependency.

Possible Solutions

Option fake install

Similar to paket install. Open points: Would it write/update the intellisense file -> probably yes

Option fake update

Similar to paket update. Open points: Would it write/update the intellisense file -> probably yes

Option fake paket <..>

Will execute paket <..> (internally). And write/update intellisense files if needed?

Option fake compile

Will execute something similar to paket install (ie. add/download new packages), update intellisense files and compiling the script (without running it). fake run should be fast and cached afterwards.

This option could have additional parameters in the future:

• fake compile --update to update dependencies similar to deleting the lockfile and paket update
• fake compile --no-install to only compile and without paket install

[matthid]

After discussing what the CLI should look like (fake install, fake update, fake prepare, fake download, fake restore ...) I'd accept a PR for this. From time to time I thought about this as well. (you should feel free to send a PR as changing the CLI shouldn't be a problem)

[nojaf]

Hi @matthid , thanks for the approval.
Could you give me some directions on getting started?
What should the cli look like? Could it be an option to just do something like fake.exe paket <command> and act accordingly?

[matthid]

That would be an even bigger change and probably be seen sceptical by some users. It would need a change similar to fsprojects/Paket#3338 before we can start here

[BlythMeister]

If I understand your aim is to perform the compile stage of running fake. Without running your script.

So why not use a similar syntax to ’fake run <script>‘ and do ’fake compile <script>‘

[baronfel]

An additional thought I had with @TheAngryByrd tonight would be to package up that compiled version of the fake-script dll into a single deployable artifact somehow. Ideally a .net core static-linked exe, but that might not be feasible.

[matthid]

@baronfel Yes I thought about that as well, this is useful especially for release pipelines, however this is a separate issue imho

[matthid]

@BlythMeister I like fake compile as well

[nojaf]

@matthid just to be on the safe side, what does fake compile do for you?
I'd like something that installs my fake deps. Compile sounds like you will compile that fsx to a dll?

[matthid]

@nojaf Yes it would do everything, load all deps, generate intellisense files and compile the script (cached behind the scenes), such that everything is ready for fake run

[matthid]

And it really would be a fake specific operation and could have options like fake compile --no-install to skip the paket install step if needed

[nojaf]

Ok, would you mind writing out a small summary of all the commands. What each should do?
I could perhaps start then with fake install and fake update.

[matthid]

Imho the commands are different ways to solve the problem of this issue. I'll update the first post