elm-make-server

A manager for co-ordinating elm-make instances.

Problem

The elm-make program does a great job using multiple threads to speed up the compilation. Unfortunately this can be a problem when there is a more than one instance of elm-make running at a time. They both go about their job as if they are the only running instance and so end up using too many threads, stepping on each other and going slowly. More slowly than if run in sequence, I think.

Benefits of elm-make-server

With elm-make-server you only have one compiler running at any one time. That includes builds triggered by webpack and by your editor integrations. This means you never hit problems with multiple compiles being triggered at once and all of them going slowly.

It also allows different compile jobs to have different priorities. Generally you want builds triggered by your editor integration to have priority over a webpack build as you're expecting immediate feedback for it to be displayed in your editor. With elm-make-server you can set up your editor builds to have priority so that lower priority builds are killed to make way for your editor build and then restarted afterwards without any disruption.

How

You run a server with elm-make-server and then add a new 'elm-make' to your PATH which is a wrapper script which sends the compilation request to the server instead of running it directly. The server then makes sure that it is only running one compile at a time.

Status

Alpha. I've been putting this together in my spare time and haven't had a chance to test to thoroughly in my work set up. The basics seem to be in place though.

Feedback

Please let me know if you use it and have any luck! Suggestions & changes welcome. It would be nice to improve the user-friendliness of the set up.

Set up

1. Clone this repository
2. Run install with npm or yarn
3. Run ./setup. This creates a bin directory with our elm-make replacment script.
4. Run elm-make-server
5. Open a new shell & navigate to your elm project directory
6. Add the bin directory created in step 3 to your PATH
7. Run elm-make, or your webpack build, or your editor. You should see the build being handled in the shell running the server command in step 4.

Prioritising Jobs

As mentioned above it can be used for different build jobs to have different priorities. I would rather my editor integration elm-make was prioritised over the webpack build.

To achieve this you can set an ELM_SERVER_PRIORITY environment variable. Priority 1 is the highest priority. The default value is 10. In my typical set up, I would have 1 in my editor set up, 5 in the shell that I sometimes do builds from and 10 in the webpack shell.

Webpack

I have struggled to get the elm-make replacement script to work with Webpack. Somehow it finds the old elm-make executable despite my best efforts. To work around that you can use the pathToMake configuration for the elm-webpack-loader to point directly at the elm-make script created in step 3 of the set up above.